f Serum creatinine levels at day 2 post-renal IRI. h Relative Krt20 mRNA levels in kidney at day 2 post-renal IRI. i Experimental group left and serum urea levels AUC post-renal IRI after one week of preconditioning with Ctrl or HC.

k Relative Krt20 mRNA levels in kidney at day 2 post-renal IRI. l Kaplan-Meier survival curve post-renal IRI after one week of preconditioning with Ctrl or HC.

m Serum aspartate aminotransferase AST and n alanine aminotransferase ALT enzyme levels at the indicated time post-hepatic IRI. Images 1a, 1e and 1i were partly created with BioRender.

In a-d and l-o , experiments were carried out in weeks old male mice; in e-h, in week-old female mice; in i-k , in month-old male mice. See also Supplementary Data Fig. Sex-specific differences have been observed in preclinical models of renal ischemic injury. In particular, females recover more readily from IRI than males In accordance with what was observed in males, HC preconditioning reduced IRI in female mice Fig.

Similarly, serum creatinine levels Fig. Some benefits of DR appear lost when started late-in-life 44 , but most surgical patients are older. Thus, we asked whether HC was similarly effective in aged male mice months-old.

As in young mice, HC preconditioning improved renal function upon IRI in old mice Fig. Finally, we tested whether HC could also protect from surgical stress by using a mouse model of hepatic IRI, as previously described Taken together, these data suggest that pre-operative HC confers hepatic and renal protection against surgical stress, independent of sex or age.

Having demonstrated that one week of carbohydrate loading increased surgical stress resistance, we then sought to identify the underlying nutritional mechanism.

Given the links between dietary restriction and protection from surgical stress 14 , we hypothesized that carbohydrate loading would impact food intake. Indeed, HC induced a voluntary 2-fold reduction in solid food intake Fig.

Strikingly, mice on HC doubled their water intake Fig. Changes in the HC group drove a significant increase in total energy intake relative to body weight Figs.

One week of HC did not affect bodyweight, lean or fat mass percentages compared to Ctrl Fig. When examining the contribution of each macronutrient to whole body energy intake, HC resulted in a significant increase in energy from carbohydrates Figs.

In both sexes and aged male mice, HC induced a reduction in food intake, associated with a 2-fold increase in sucrose-water intake Supplementary Data Figs. Similarly, body weight was unaffected Supplementary Data Fig. b Total calorie intake normalized to body weight by day.

c Body weight at the indicated time in mice given ad libitum access to Ctrl or HC. d Total calorie intake by macronutrient normalized to body weight by day. e Relationship between sucrose intake and protein intake, and f fiber intake and protein intake in humans from the US National Health and Nutrition Examination Survey NHANES.

Box plots represent median with 25th and 75th percentile. Whiskers plots represent hinge ± 1. The red line indicates the level of the control group Ctrl.

h Serum urea levels AUC post-renal IRI after one week of preconditioning with the indicated diet. i Serum creatinine levels at day 3 post-renal IRI. j Relative Krt20 mRNA levels in kidneys at day 2 post-renal IRI after one week of preconditioning with the indicated diet.

Serum urea levels AUC post-renal IRI after one week of preconditioning with the indicated diet. n Relative Krt20 mRNA levels in kidney at day 2 post-renal IRI after one week of preconditioning with the indicated diet.

o Relationship between serum urea at day 2 post-renal IRI and dietary protein intake or carbohydrate or fat intake. In all surfaces, red indicates the highest value while blue indicates the lowest value, with the colors standardized across each slice.

In a — d and g — o , experiments were carried out in weeks old male mice. See also Supplementary Data Figs. Given the robustness of these data, we asked whether similar effects could be observed in humans.

Total carbohydrate and protein intake was analyzed from the National Health and Nutrition Examination Survey NHANES from to including two h dietary recalls per person on a representative sample of the United States population every 2 years four distinct cycles of data collection. Given the voluntary protein restriction observed during carbohydrate loading, and because restricting dietary protein has pronounced effects on glucose tolerance 26 , lipid metabolism 24 and resistance to IRI 12 in vivo, we hypothesized that HC might not have additional benefits in mice fed a low protein LP diet.

To test this hypothesis, we fed an additional cohort of mice an LP diet Supplementary Data Figs. Similar to mice on a standard diet, mice on an LP diet with access to HC decreased their food intake and increased their water and total energy intake Supplementary Data Fig. Mice on an LP diet for one week lost weight Supplementary Data Fig.

In line with our hypothesis that the benefits of carbohydrate loading are mediated by protein dilution, mice fed with an LP diet with access to HC had no additional protection from IRI, as assessed by tissue necrosis, serum urea, creatinine levels, and Krt20 expression Fig.

Next, we asked whether the reintroduction of protein would reverse the benefits of HC. To achieve this, we administered cysteine, a sulfur-containing amino acid previously shown to be relevant in the beneficial effects of DR 14 , via oral gavage to mice treated with HC.

We estimated the amount of cysteine to be 5. Interestingly, food, water, total energy intake, and body weight were unaffected by cysteine add-back Supplementary Data Fig.

This was evident by increased serum creatinine at day 1 and serum urea levels after IRI Fig. Finally, we utilized the geometric framework 26 to evaluate the effects of ad libitum -fed diets varying in macronutrients on kidney function serum urea.

Resistance to surgical stress was most robustly associated with protein intake Fig. In contrast, fat and carbohydrate intake had negligible influence.

Overall, we found that one week of HC increased total caloric intake while reducing protein intake, which is required for resistance to surgical stress. Nutrient sensing pathways proposed to link dietary restriction with stress resistance include H 2 S production downstream of the integrated stress response Activating Transcription Factor 4; ATF4 and oxidative stress responses NRF2.

We previously demonstrated that H 2 S was necessary and sufficient for increased stress resistance under certain DR paradigms 13 , Surprisingly, HC in both standard and LP diets did not induce the H 2 S-producing enzyme cystathionine-γ-lyase CGL; Cth gene in either the liver or kidney Supplementary Data Fig.

Similarly, H 2 S production capacity in the liver, kidney, and serum was unaffected by HC Supplementary Data Fig. Fibroblast growth factor 21 FGF21 is another key nutrient-sensing molecule In both rodents and humans, one month of protein restriction increases FGF21 and drives key physiologic adaptations, including thermogenesis and altered feeding behavior 32 , 37 , Here, one week of HC induced a fold increase in serum FGF21 levels Fig.

HC induced a similar increase in serum FGF21 levels in females Supplementary Data Fig. The LP diet increased serum FGF21 levels to a greater extent, but the combination of HC water and the LP diet did not result in an additional increase Fig.

FGF21 is a metabolic hormone predominantly produced in the liver Here Fgf21 mRNA expression was restricted to the liver, with low expression in the kidney, skeletal muscle, and adipose tissue Supplementary Data Fig. Consistently, FGF21 induction was observed in the liver Fig. In accordance with the activation of FGF21, HC increased whole-body metabolic rate, as shown by VO 2 consumption Supplementary Data Fig.

Similarly, the effects of HC were driven by protein dilution, as no additive effect was observed in mice fed an LP diet Supplementary Data Fig. Serum FGF21 levels correlated negatively with dietary protein intake Fig.

b Relative liver Fgf21 mRNA levels after one week of preconditioning with the indicated diet. c Relative kidney Fgf21 mRNA levels after one week of preconditioning with the indicated diet. d Linear regression showing the relationship between serum FGF21 levels versus protein intake and e serum urea AUC.

h Fold change of top DEGs from GSE in liver after one week of preconditioning with HC compared to Ctrl. In all panels, experiments were carried out in weeks old male mice. To further explore the importance of HC-mediated induction of FGF21 signaling, we sought to compare the Fgf21 transcriptional signature to one week of HC.

To do so, we examined the hepatic differentially expressed genes DEGs from a publicly available dataset of Fgfoverexpressing mice GSE Of these 31 DEG, the top 10 highest from the Fgfoverexpression dataset were similarly upregulated in the livers of HC mice Fig. Together, these data support the hypothesis that HC effects on stress resistance are mediated by FGF21 signaling induced downstream of dietary protein dilution.

The necessity of FGF21 for HC-mediated benefits was tested with whole-body Fgf21 deletion Fgf21 KO mice Fig. HC-mediated changes in body weight Supplementary Data Fig. However, while the absence of FGF21 had no effect on renal IRI response in Ctrl mice, Fgf21 KO mice failed to gain protection upon HC, as demonstrated by serum urea Fig.

Finally, we tested whether protection against general surgical stress conferred by HC required FGF In addition, Hmgb1 mRNA expression, a biomarker of cellular stress responses and damage-associated molecular patterns 46 , was decreased in Fgf21 WT mice on HC, but not in Fgf21 KO mice Fig.

In conclusion, our findings demonstrate that FGF21 is required for surgical stress resistance via mechanisms that may be independent of diet-induced metabolic adaptations. b Food left and water right intake normalized by body weight after one week of preconditioning with the indicated diet.

c Serum urea AUC and d serum creatinine levels at day 2 post-renal IRI after one week of preconditioning with the indicated diet. g Relative Krt20 mRNA levels in the kidney at day 2 post-renal IRI after one week of preconditioning with the indicated diet.

h Serum aspartate aminotransferase AST and alanine aminotransferase ALT enzyme levels at the indicated time post-hepatic IRI. Ischemic areas appearing in light pink. j Relative Hmgb1 mRNA levels in the liver at day 2 post-renal IRI after one week of preconditioning with the indicated diet.

Fgf21 WT Ctrl. In a-j , experiments were carried out in Fgf21 WT and Fgf21 KO weeks old male mice. Long-term treatment with FGF21 agonists improves circulating lipid profiles in humans 47 , but could negatively impact blood pressure with long-term use After showing that FGF21 was required for protection against IRI, we tested whether short-term FGF21 treatment was sufficient to confer protection against surgical stress.

During the baseline period prior to surgery, and consistent with previous findings in Fgf21 transgenic mice 35 , total food intake and water intake doubled in mice treated with FGF21 Fig. On day 7 of treatment, FGFtreated mice had a lower body weight compared to the control group Supplementary Data Fig.

Similar trends were observed for protein, carbohydrate, and lipid intake Supplementary Data Fig. Serum urea was significantly decreased in FGFtreated mice compared to Veh Fig. Serum creatinine at day 2 post-renal IRI was similarly reduced Fig.

FGF21 preconditioning also decreased the expression of Krt20 Fig. Together, these data are consistent with the hypothesis that FGF21 treatment for one week is sufficient to recapitulate HC-induced surgical stress protection.

a Experimental setup. b Serum FGF21 levels left and AUC right post-renal IRI after one week of preconditioning with the indicated treatment. c Food left and water right intake normalized by body weight after one week of preconditioning with the indicated treatment.

d Serum urea levels left and AUC right at the indicated time post-renal IRI. e Serum creatinine levels at day 2 post-renal IRI after one week of preconditioning with the indicated treatment.

f Relative Krt20 mRNA levels at day 2 post-renal IRI after one week of preconditioning with the indicated treatment. Image1A was partially created with BioRender.

In b-h , experiments were carried out in week-old male mice. We finally sought to understand the changes in gene expression induced by FGF21 during HC, and how they underlie the protective effects on IRI.

To do this, we identified gene expression modules associated with serum FGF21 expression in both kidney and liver transcriptomic datasets using weighted correlation network analysis WGCNA. For the kidney, we performed bulk RNA-seq in mice preconditioned for one week with either Ctrl or HC on both standard and LP diets.

To identify the genes associated with various kidney and liver phenotypes and traits, all expressed protein-coding genes were aggregated and analyzed using WGCNA, including genes for kidney and for liver.

A total of 13 and 15 WGCNA modules were identified Supplementary Data Fig. Ets and Nf K b have been implicated in the regulation of immune and cell survival processes, while PPARγ has been identified as a key regulator of cellular metabolism.

ATF3 and ATF4 are involved in cellular stress responses, including amino acid deprivation and oxidative stress, while UQCRB is a subunit of complex III in the mitochondrial electron transport chain, suggesting the induction of tissue regeneration or repair-like responses. To validate our analysis, we employed an alternative method, identifying positively Fig.

In addition, network and transcription factor analysis identified PPARγ and Nf K b, as well as Trp53 and ATF4 Fig. Together, these results suggest that activation of stress responses and cell survival pathways is associated with FGF21 induction during HC. a Module-Trait relationships with serum FGF21 levels identified through Weighted Gene Co-expression Network Analysis WGCNA from kidneys of male mice given access to ad libitum Ctrl, HC, LP and LPHC diet for one week.

Top line corresponds to Pearson R 2 and bottom line to adjusted p value. Color scales represent positive correlation red and negative correlation blue. c Common biological processes GO terms enriched in kidney and liver modules with significant positive and d negative Module-Trait relationships with serum FGF21 identified through WGCNA.

The dot size corresponds to the number of genes in the pathway. The color of the dots indicates the degree of significance of the pathway enrichment, with darker shades indicating higher significance.

e Heatmap of percentile-transformed expression levels of the top 15 genes from kidney and liver f modules with significant Module-Trait relationships with serum FGF Yellow indicating high expression and blue indicating low expression.

The genes from each module with positive Module-Trait relationships with serum FGF21 were used in STRING and non-singleton were used for transcription factor analysis TFA. The motifs picture shows the top NES motifs and their associated direct transcription factors.

Top panel shows genes with positive slopes, while bottom panel shows negative slopes, reflecting protein dilution intake. Yellow indicates high expression and blue indicates low expression. Upregulated genes were used in STRING and nonsingleton were used for transcription factor analysis TFA.

In this study, we demonstrate that one week of carbohydrate loading induces protein dilution in mice, which confers protection from surgical stress in vivo via FGF We not only found that short-term carbohydrate loading is sufficient to induce protein dilution, but also demonstrated that these benefits can be achieved under hypercaloric conditions.

In fact, we are among the first to demonstrate a dietary intervention that protects from surgical stress without inducing body weight reduction.

A model is presented in Supplementary Data Fig. Voluntary adherence to a dietary restriction is difficult for most people. One potential benefit of carbohydrate loading is that it does not involve forced food restriction but instead promotes an alternative source of energy and spontaneous macronutrient dilution.

The response to carbohydrate was consistent across sex and in older mice, supporting the general validity of our findings. The observational human data from the USDA NHANES suggested an inverse association between sucrose and protein intake, indicating the potential for conserved appetitive mechanisms.

However, the metabolic response and the extent to which carbohydrate loading may result in favorable outcomes in humans are still unknown. As with any epidemiologic study, the association of macronutrient intake can be confounded by any other variable lifestyle, other dietary factors, comorbidities, medications, etc.

Although protein energy intake was treated as a single variable, it truly is a combination of amino acid ratios that cannot be fixed, even in mice which limit drawing conclusions about the effects of dietary protein in humans. The latter is similar to most murine dietary protein restriction regimen, that replaced dietary protein with carbohydrates utilized complex carbohydrates derived from starch 15 , While we did not study the interactions between carbohydrate sources here, one of the few studies testing the effects of carbohydrate composition during protein dilution showed that a sucrose-rich diet improved metabolic parameters compared to a mixture of glucose and fructose Of interest, carbohydrate loading resulted in an overconsumption of excess energy from sucrose and a voluntary reduction in protein intake.

Rodents have a dominant protein appetite, which drives food intake to reach a protein target 52 via an FGFdependent mechanism 37 , Thus, protein-restricted diet typically results in the overconsumption of total energy.

This response is called protein leverage While we do replicate the protein leverage hypothesis in mice fed low protein with normal water, we interestingly observe that mice given sucrose-water do not increase food intake on a low protein diet.

This suggests the intriguing possibility that liquid carbohydrate intake may override protein leverage. Future studies may test the resulting hypothesis that FGF21 action on drinking behavior may override its action on feeding behavior, or that an FGFindependent mechanism affects feeding behavior upon liquid carbohydrate intake.

Consistent with the latter hypothesis, carbohydrate loading-mediated changes in food and water intake were unaffected by the absence of FGF On the other hand, exogenous FGF21 administration, without any dietary intervention, was sufficient to increase both water and food intake.

While protein restriction is required for the benefits of carbohydrate loading, this suggests that protein restriction might be dispensable for FGF21 benefits when given exogenously. These differences in the metabolic response to dietary protein restriction and protein dilution during carbohydrate loading will need to be further investigated.

Additionally, liquid carbohydrate loading may be a previously unrecognized method to limit protein intake. The response to dietary protein is also not linear. In our study, when comparing carbohydrate loading 3.

This is consistent with the idea of a threshold and non-linear effects 41 , 54 A study comparing a range of sucrose concentrations during carbohydrate loading would be of interest to better investigate the potential for dose response to carbohydrate loading.

The duration of carbohydrate loading required for the onset of stress resistance benefits is unknown. Here, we show that only one week of carbohydrate loading is sufficient for the observed benefits in mice with maximal FGF21 induction already achieved after two days, indicating that this relatively short duration of carbohydrate loading might be sufficient to yield the observed benefits.

Whether or not longer periods of carbohydrate loading will further increase protection remains to be experimentally determined. Our previous results demonstrated that CGL is required for the benefits of DR, including protection from ischemia 13 and IRI Protein restriction was associated with a decrease in CGL expression and cysteine level 41 , while caloric and methionine restriction were previously demonstrated to increase both CGL and H 2 S production.

CGL expression was also increased in response to a high-protein diet 55 , but was not affected in long-lived mice overexpressing Fgf21 35 , Instead, FGF21 appears to be the molecular mediator of the benefits of carbohydrate loading.

Additionally, we propose that HC-mediated protection from IRI functions as a para- and endocrine mechanism involving hepatic secretion of FGF21, consistent with a previous report This could serve as a basis for FGFbased therapeutics during surgical stress or trauma, where there is currently no widely accepted risk mitigation strategy.

FGF21 is a critical mediator of protein restriction In line with previous studies, we show that FGF21 signaling increases energy expenditure and thermogenesis 34 , 38 , During protein restriction, FGF21 signaling is essential to regulate adaptive, homeostatic changes in metabolism and feeding behavior 32 , Consistent with others 45 , we found that carbohydrate loading induction of FGF21 caused increased adipose UCP-1 and increased energy expenditure.

The importance of FGF21 signaling during carbohydrate loading also emphasizes that protein restriction is a key driver of the observed benefits. Of note, in mice lacking ATF3, IRI was increased after orthotopic liver transplantation, which was associated with inhibition of HO-1 signaling and increased TLR4 as well as NFκB signaling ATF4 can induce hepatic FGF21 in both ATF4-overexpressing mice and a model of endoplasmic reticulum stress through eIF2alpha and the unfolded protein response However, the role of ATF4 in dietary restriction is complicated, as it is not required for FGF21 induction upon methionine restriction Similarly, NRF2 was not required for calorie restriction-dependent protection from hepatic IRI However, activation of NRF2 reduced tubular damage upon renal IRI and was associated with FGFmediated protection against diabetic nephropathy 61 , Current clinical recommendations for the clinical presurgical care are to 1 avoid fasting, 2 initiate nutritional support or supplementation without delay, and 3 reduce factors that exacerbate stress-related catabolism or impair gastrointestinal function 4 , 5.

Thus, our findings carry significant implications for the development of nutritional strategies during surgery. While our data suggest an inverse correlation between protein and sucrose intake in humans, the impact of short-term carbohydrate loading on calorie and protein intake in patients undergoing surgery remains to be established.

Additionally, the impact of such interventions in humans with altered glucose metabolism insulin resistance, metabolic syndrome, etc. will need to be carefully evaluated prior to initiating a clinical trial. On the other hand, FGF21 could be an alternative strategy for those who are not able to tolerate carbohydrate loading Counterintuitively, FGF21 levels are increased in patients with obesity and chronic kidney disease CKD 64 , This may be explained by FGF21 resistance, which is also associated with worse metabolic profiles, higher inflammatory markers, more comorbidities, and higher mortality in CKD patients Interestingly, in our study in FGFsensitive mice, short-term FGF21 delivery was sufficient to recapitulate the benefits of HC drinks without the need for prolonged administration, thus highlighting the translational potential.

In conclusion, in ad libitum -fed mice, carbohydrate loading promotes dietary protein restriction, the adaptive stress response, and resilience to surgical stress. ERAS® approaches currently promote short-term carbohydrate loading drinks to improve postoperative recovery without clear mechanistic explanations.

Here, we identified FGF21 as a key molecular mediator of carbohydrate loading. These findings have broad implications for our basic understanding of the impact of carbohydrate and protein-carbohydrate interactions on metabolic health. Finally, our results provide a rationale for short-term carbohydrate loading or FGFbased therapeutics during surgery, for which there is now no widely accepted risk mitigation strategy.

All experiments were performed with the approval of the cantonal Veterinary Office Service de la Consommation et des Affaires Vétérinaires SCAV-EXPANIM, authorization number , b and All animal experimentation conformed to the Guide for the Care and Use of Laboratory Animals.

All efforts were made to minimize animal suffering, including the use of anesthesia and analgesia during surgical procedures as well as humane endpoints to prevent undue distress. Animals were monitored daily. Fgf21 knockout Fgf21 KO was generated by crossing Fgf21 loxP mice B6.

The resulting offspring had a deletion in exons of Fgf21 in all tissues. The line was subsequently maintained by breeding animals heterozygous for the Fgf21 deletion allele. Mouse ear biopsies were taken and digested in DirectPCR lysis reagent with proteinase K.

All experimental diets were based on diet from Granovit AG Kaiseraugst, Switzerland , with The low protein LP diet was custom prepared by Granovit AG based on diet with 6. The nutritional value of the control diet was 3.

HC drink was changed every two days. Food pellets and bottles were weighed daily in every cage of mice. The delta weight of food and drink was calculated, divided by the number of mice, and normalized by the weight of each individual mouse in the cage.

The cysteine solution concentration was calculated from the difference of daily food intake, in weight of food, between mice given ad libitum access to water Ctrl and HC. According to the diet composition, cysteine constitutes 0.

A stock solution containing a concentration of Following a 2-cm abdominal incision, the vascular pedicles of the right and left kidneys were identified under a microscope. First, the right renal artery, vein, and ureter were ligated and cauterized.

Immediately after, the right kidney was dissected and flash-frozen in liquid nitrogen. A darkening of the kidney was observed to ensure that the pedicle had been successfully clamped. Liver IRI was performed as described previously Following a 2-cm abdominal incision, the vascular pedicles of the median lobe and left lateral lobe were identified under a microscope.

Blanching of the lobes was observed to ensure that the artery had been successfully clamped. The abdominal incision was sutured with Prolene, and surgical staples were used to close the skin , Aichele Medico AG.

All mice received subcutaneous buprenorphine 0. Of note, the surviving mice involved in the survival experiment were euthanized after 8 days. The remaining kidney was collected and cut in half transversally. Mice were injected intra-peritoneally i. once a day for three days prior to the kidney IRI surgery.

At the conclusion of the measurements, the mice were weighed again. Energy expenditure was determined using a computer-controlled indirect calorimetry system PromethionH, Sable Systems, Las Vegas, NV as published Animals had unlimited access to food and water throughout the study.

XYZ beam arrays BXYZ-R, Sable Systems, Las Vegas, NV were used to record ambulatory activity and position, and respiratory gases were measured using an integrated fuel cell oxygen analyzer, a spectrophotometric CO 2 analyzer, and a capacitive water vapor partial pressure analyzer GA3, Sable Systems, Las Vegas, NV.

Oxygen consumption and CO 2 production were monitored for 1-minute at 5-minute intervals. The respiratory quotient RQ was determined by dividing CO 2 production by O 2 consumption.

MetaScreen v. FITC-sinistrin clearance was utilized to determine the glomerular filtration rate. Mice were anesthetized with isoflurane and subsequently had their right flanks shaved. Body composition EchoMRIH, Echo Medical System, Houston, TX was obtained on awake mice contained in a thin-walled plastic cylinder with a cylindrical plastic insert to restrict their movement.

Mice were exposed to a low-intensity electromagnetic field for a brief period, and their fat and lean mass were determined. The kidneys were scored histologically using a modified Goujon scoring method 70 , 71 , The kidneys were imaged at a magnification of 20x using a Zeiss Axioscan Z.

The entire scanned section was analyzed using Zen Blue 3. The same procedure was followed in the remaining categories. After that, the score for each category was converted to a percentage of damage.

On a scale of 0 to 25, the final score was the sum of the scores for each category. Necrotic areas were identified using the following criteria: tubules with large debris, large dilation, and tubular cell loss; tubules with cast formation; and tubule loss.

The pelvis region has been excluded from quantification. The necrotic area of digitally highlighted images was measured by calculating the highlighted area fraction using ImageJ v1. Slides were further counterstained with hematoxylin.

The positive immunostaining area was quantified using the Fiji ImageJ 1. cDNA samples were loaded into a well plate format Applied Biosystems, ThermoFischer Scientific AG, Switzerland using SYBR Green reagent—based PCR chemistry l reaction volume containing specific forward and reverse primers.

RPL27 was chosen as the housekeeping gene Ct values for candidate and housekeeping genes were determined, and standard curves for each gene were calculated using serial dilutions. The relative standard curve method was used to determine the relative level of expression of genes.

For gene encoding, the primers listed in supplementary Table S1 were used, and analysis was performed using the QuantStudioTM 1. Triglyceride concentration was determined using a Sigma kit Cat TR The serum creatinine level was determined using the mouse Creatinine Assay Kit , Crystal Chem INC.

H 2 S production was quantified in the kidney and liver, as previously published 13 , Briefly, tissue powder was homogenized in passive lysis buffer PLB E, Promega and the protein concentration was determined using the ThermoFisher Pierce TM BCA Protein Assay Kit Cat All data were analyzed in R v.

Data involving response surfaces were analyzed using Generalized Additive Model GAM and previously described Briefly, GAMs with thin-plate splines were used to model the responses to the macronutrient composition of the diet.

GAMs were fitted using the mgcv tool of the R programming language v1. The effects of macronutrients were divided into main effects and interactions.

The response included post-renal IRI serum urea levels. Data from the US Department of Agriculture National Health and Nutrition Examination Survey were analyzed as previously described Briefly, NHANES XPT data files were downloaded from the CDC NHANES website for surveys carried out from The data were imported into R using the sasxport.

get function from the Hmisc package. Individuals who were not pregnant, over the age of 18 years, and had two complete hour dietary recalls were included. As no gender-differences were observed, genders were pooled for the final analysis presented in the manuscript.

Data preprocessing, statistical computation, and visualization were performed using the Omics Playground version v2. Data preprocessing included filtering genes based on variance, expression across the samples, and missing values.

Only protein-coding genes on non-sexual chromosomes were included in the analysis. Batch effects were identified by an F-test for the first three principal components.

Batch correction was performed for explicit batch variables or unwanted covariates. For gene-level testing and identification of differentially expressed genes DEG , statistical significance was assessed using two independent statistical methods: voom and limma-no-trend.

Only genes that were significant using both methods were included. For slope analysis , normalized genes were correlated with the mean protein intake of each group Ctrl, HC in both regular and low protein diets to identify protein dilution-driven genes.

Bonferroni corrections were applied to multiple Pearson correlations. Raw counts were normalized by performing a variance-stabilizing transformation using the DESeq2 package in R v1.

The variance-stabilizing transformed gene expressions were subjected to WGCNA based on the WGCNA package in R v1. Function annotations of the genes were obtained using the org.

db package in R v3. Intramodular analysis identified genes with high gene-module membership and gene-trait significance. The ClusterProfiler package in R v4.

Transcription factor binding motifs, which are enriched in the genomic regions of a query gene set, were determined using the iRegulon plugin version 1. The cis-regulatory control elements of genes from each module associated with serum FGF21 were used in the iRegulon analysis.

Gene expression of selected genes underwent a z-transformation, and the top genes from each module were used for the heatmaps using pheatmap in R v1. RNA sequencing publicly available data of liver of the Fgf21 transgenic mice GSE 35 and protein restriction diet SRA accession PRJNA 41 were analyzed following the same pipeline.

All experiments adhered to the ARRIVE guidelines and followed strict randomization. All experiments and data analysis were conducted in a blind manner using coded tags rather than the actual group name.

A power analysis was performed prior to the study to estimate sample-size. Animals with pre-existing conditions malocclusion, injury, abnormal weight were not operated or excluded from the experiments upon discovery during dissection kidney disease, tumor etc. All experiments were analyzed using Prism 9.

Correlation analyses were determined using Linear Regression Test. A P value inferior or equal to 0. Correlation analysis were determined using Linear Regression Test.

Artworks in figures S1A and S9 were created with BioRender. com Academic License Terms, www. Further information on research design is available in the Nature Portfolio Reporting Summary linked to this article.

All other relevant data are available from the corresponding author on request. The publicly available sequencing data generated in this study have been deposited in the National Center for Biotechnology Information Gene Expression Omnibus GEO and are accessible through the GEO Series accession number GSE and through SRA accession PRJNA Dobson, G.

Trauma of major surgery: A global problem that is not going away. Article PubMed PubMed Central Google Scholar. Jaeschke, H. Molecular mechanisms of hepatic ischemia-reperfusion injury and preconditioning. Liver Physiol. Article CAS PubMed Google Scholar. Chouchani, E. et al. Ischaemic accumulation of succinate controls reperfusion injury through mitochondrial ROS.

Nature , — Article ADS CAS PubMed PubMed Central Google Scholar. Gustafsson, U. Guidelines for perioperative care in elective colonic surgery: Enhanced Recovery After Surgery ERAS R Society recommendations. World J. Singh, S. survey of pre-operative carbohydrate-containing beverage use in colorectal enhanced recovery after surgery ERAS programs.

Lond 10 , 19 Article PubMed Google Scholar. Bilku, D. Role of preoperative carbohydrate loading: a systematic review.

R Coll. Article CAS PubMed PubMed Central Google Scholar. Varadhan, K. The enhanced recovery after surgery ERAS pathway for patients undergoing major elective open colorectal surgery: a meta-analysis of randomized controlled trials.

Budhathoki, S. Association of Animal and Plant Protein Intake With All-Cause and Cause-Specific Mortality in a Japanese Cohort.

JAMA Intern. Mitchell, J. Short-term dietary restriction and fasting precondition against ischemia reperfusion injury in mice. Aging Cell 9 , 40—53 Verweij, M.

Liver Transpl. Harputlugil, E. The TSC complex is required for the benefits of dietary protein restriction on stress resistance in vivo. Cell Rep.

Robertson, L. Protein and Calorie Restriction Contribute Additively to Protection from Renal Ischemia Reperfusion Injury Partly via Leptin Reduction in Male Mice. Longchamp, A. Cell , — e Hine, C. Endogenous hydrogen sulfide production is essential for dietary restriction benefits.

Cell , — Trocha, K. Short-term preoperative protein restriction attenuates vein graft disease via induction of cystathionine gamma-lyase. Orentreich, N. Low methionine ingestion by rats extends life span. CAS PubMed Google Scholar. Peng, W.

Surgical stress resistance induced by single amino acid deprivation requires Gcn2 in mice. Article Google Scholar. Kip, P. Insights From a Short-Term Protein-Calorie Restriction Exploratory Trial in Elective Carotid Endarterectomy Patients.

Endovascular Surg. Partridge, L. The quest to slow ageing through drug discovery. Drug Discov. Green, C. Molecular mechanisms of dietary restriction promoting health and longevity. There are 2 types of fibre: soluble, which dissolves in water and can help lower blood glucose and cholesterol levels, and insoluble, which can help food move through your digestive system, promoting regularity and helping prevent constipation.

It is important to understand the different types of carbohydrates and their roles to better optimise dietary strategies such as carb loading, to improve athletic performance. Carb loading is primarily intended for endurance athletes preparing for prolonged, intensive events, typically those lasting 90 minutes or longer.

This is because such strenuous activities deplete glycogen stores in muscles, which could result in fatigue and reduced performance. By carb loading, athletes aim to maximise their glycogen storage, which can enhance their endurance and delay the onset of fatigue.

Examples of activities where carb loading may be beneficial include marathon running, long-distance cycling, triathlon events, and long-distance swimming.

However, it's less relevant for sports involving short bursts of activity, such as sprinting or weightlifting, and for activities of a lower intensity or shorter duration. While carb loading can be beneficial for endurance athletes, it's important to note that it should be approached with care.

Not every endurance athlete will respond to carb loading in the same way, and individual dietary needs can vary widely. Carb loading primarily benefits athletes by enhancing their endurance. By maximising muscle glycogen, the body's preferred form of carbohydrate during exercise, athletes can maintain a high level of exertion for longer periods during endurance events, thus delaying the onset of fatigue.

Consuming glycogen after exercise helps replace muscle glycogen depleted during exercise, and aids in storing more glycogen as an adaptation to training. This is especially beneficial when events are spaced closely together — generally, if events are less than 8 hours apart.

The importance of carbohydrates extends beyond physical performance to mental acuity as well. Sufficient carbohydrate intake fuels the brain, aiding in maintaining focus and decision-making during endurance events.

Research suggests that consuming a high carbohydrate intake prior to a long-duration endurance event may delay the onset of fatigue and reduce risk of injury, further boosting the athlete's capacity for sustained performance.

However, carb loading strategies should be personalised, as individual needs and responses can vary greatly. Timing is crucial when it comes to carb loading. Begin the process approximately 36 — 48 hours prior to your event. This timeframe allows your body to store glycogen, the primary fuel source during prolonged exercise.

To determine the right amount of carbohydrates to consume, it's advisable to consult with a sports dietitian.

They can assess your individual needs and recommend a specific daily intake. Generally, athletes are advised to consume around 8 — 12 grams of carbohydrates per kilogram of body weight per day during the carb loading phase.

In conjunction with increased carbohydrate consumption, it's important to implement an exercise taper during this period.

Reducing the intensity and volume of your workouts allows your muscles to recover and glycogen stores to be maximised. A useful tip would be to practise carb loading as part of training prior to the actual competition or event. This will allow you to experiment with different strategies, gauge their effectiveness, and make any necessary adjustments.

By doing so, you can optimise your performance and fuel your body effectively for the endurance challenge ahead. It's important to note that carb loading protocols may vary among athletes. To develop a personalised plan, it is recommended to discuss your specific needs with both a sports dietitian and physical trainer.

They can guide you through the process, fine-tuning the dietary and training aspects to suit your individual requirements.

Carb loading doesn't mean you should increase your total daily calories. Rather, it involves adjusting the proportion of your calorie intake that comes from carbohydrates. Overeating can lead to weight gain and feelings of heaviness or discomfort, which are not conducive to optimal performance.

Do not neglect to consume sufficient fluids prior to an endurance event to ensure that you are adequately hydrated.

Failing to properly hydrate can lead to dehydration and negatively impact your performance and recovery. Another common mistake is not consuming enough carbohydrates to maximise glycogen stores. For effective carb loading, aim for 8 — 12 grams of carbs per kilogram of body weight each day.

The exact amount of carbohydrates required prior to an event should be discussed with a sports dietitian, as this will vary across different individuals and different types of sport. This can come in the form of refined carbohydrates like bread, rice, and noodles.

Although foods and drinks high in refined sugars, such as smoothies, cereal bars, and flavoured milks are generally not recommended on a regular basis, it is acceptable to use these foods and drinks to meet the higher-carbohydrate demands of carb-loading prior to endurance events.

Some athletes consume too much fibre while carb loading, leading to gastrointestinal discomfort. In the final days leading up to the event, switching to low-fibre carbohydrate sources such as white bread instead of wholemeal bread, or regular pasta rather than wholegrain pasta can help alleviate potential digestive issues.

Some people make the mistake of consuming high-fibre or fatty foods during their carb loading phase. Fatty foods can displace the carbs needed to fill glycogen stores, and while high -fibre foods like vegetables, whole grains and fruit are healthy and recommended on a regular basis, these should not be overconsumed during the carb loading phase because they can cause digestive discomfort especially if consumed in large amounts.

While the focus of carb loading is on carbohydrates, protein should not be completely overlooked. Including a moderate amount of protein in your meals can aid in muscle repair and recovery. Speak to a sports dietitian to understand your individual protein needs and how adequate protein can be incorporated into a high-carbohydrate diet.

The days leading up to a race are not the time to try a new dietary strategy. Every athlete is unique, and you should use your periods of training to trial and fine-tune your carb loading plan. When carb loading, you should avoid high-fat and high-fibre foods and alcohol.

Instead, what you should go for are foods that are high in carbohydrates and low in fibre to maximise glycogen storage and minimise digestive discomfort. These include:. Refined grains. Choose white bread, white rice, or pasta.

While whole grains are generally healthier, they're higher in fibre, which can lead to digestive discomfort when consumed in large quantities. Refined grains, on the other hand, are more easily digested, and are therefore more appropriate to meet the high carb needs during carb loading.

Starchy vegetables. Potatoes and sweet potatoes without skin, as well as taro are some good choices. Fruit juices and canned fruits. These are high in simple sugars which are more carbohydrate-dense than fresh fruit.

It is acceptable to include foods and drinks high in refined sugars, such as juices, flavoured milk, canned fruit, and smoothies as part of the diet to meet the high carb needs during the carb loading phase. Low-fat dairy. Milk, yogurt, and low-fat cheeses provide carbohydrates along with some protein for muscle recovery.

Flavoured low-fat milks and yoghurt are a good way to provide lots of carbohydrates in a small volume. If you're interested in learning more about carb loading or are going to go on the diet for an upcoming event, our experienced dietitians can help. This is a phenomenon that has been rearing its head much more in recent years.

Athlete or not, it is important to understand its possible causes. Not everyone who participates in sports knows about the risks involved — until they get hurt.

Here are the top 5 serious sports injuries and how they can be treated. Cardiologists can provide expert advice to athletes. Professional athletes collect a score of injuries during their career. Singapore Slinger Wong Wei Long shares how he minimises sports injuries on the job.

Dr Michael Soon, orthopaedic surgeon, shares how proper conditioning and swing techniques can reduce one's risk at getting injured. As a sport, cycling is affordable, fun and an easy exercise to weave into your busy schedule.

But before you hit Google Maps to plan for a ride around your neighbourhood, it is important to know your risks and take a few precautions. Get trusted medical advice from our specialists, dietitians and physiotherapists directly in your inbox.

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Last updated: Thursday, July 13, 8 min reading time. Diane Ashley Seto Ern Dietitian. The practice of carbohydrate loading carb loading is often used by athletes to enhance performance and endurance in their sports events.

Also, increase the carbohydrate intake progressively over 5 or 6 smaller meals during the day rather than heavily overindulging with 3 meals only. Examples of high carbohydrates include wholegrain bread, brown rice, cereals, pasta, and potatoes 3 days before the event, the amount of exercise should be reduced.

Athletes must go on 3 days of complete rest and must fill up on a lot of carbohydrates during this time to fill up the glycogen stores. A breakfast meal packed with the right nutrients, e.

For events longer than 2. This needs to be done in training as the gut needs to adapt and be trained to handle high amounts of carbohydrates while exercising. After the event, provide the body with both protein and carbohydrates to recover and also replenish the carbohydrate stores. Carbohydrate loading intake will depend on the kind of sport an individual plays and the kind of training the athlete receives for it.

An athlete can feel indigestion, bloated, and constipation because the intestines are filled up with carbs. To hold so many carbohydrates and glycogen in the body, water is required. So, feeling heavier than usual is normal.

Home Blog Physiotherapy And Fitness Improve Your Athletic Performance By Carbohydrate Loading. de Ataide e Silva T, de Di Cavalcanti Alves Souza ME, Amorim JF, Stathis CG, Leandro CG, Lima-Silva AE. Can carbohydrate mouth rinse improve performance during exercise? A systematic review.

Article Google Scholar. Colombani PC, Mannhart C, Mettler S. Carbohydrates and exercise performance in non-fasted athletes: a systematic review of studies mimicking real-life. Nutr J. Currell K, Jeukendrup AE. Validity, reliability and sensitivity of measures of sporting performance.

Mitchell JB, Costill DL, Houmard JA, Fink WJ, Pascoe DD, Pearson DR. Influence of carbohydrate dosage on exercise performance and glycogen metabolism.

J Appl Physiol. CAS PubMed Google Scholar. Jeukendrup A, Brouns F, Wagenmakers AJ, Saris WH. Carbohydrate-electrolyte feedings improve 1 h time trial cycling performance.

Int J Sports Med. Hawley JA, Schabort EJ, Noakes TD, Dennis SC. Carbohydrate-loading and exercise performance. An update. Carter JM, Jeukendrup AE, Mann CH, Jones DA. The effect of glucose infusion on glucose kinetics during a 1-h time trial. Higgins JPT, Thompson SG. Quantifying heterogeneity in a meta-analysis.

Stat Med. Brockwell SE, Gordon IR. A comparison of statistical methods for meta-analysis. Coggan AR, Coyle EF. Carbohydrate ingestion during prolonged exercise: effects on metabolism and performance.

Exerc Sports Sci Rev. Article CAS Google Scholar. Jeukendrup AE. Carbohydrate intake during exercise and performance. Schubert MM, Astorino TA. A systematic review of the efficacy of ergogenic aids for improving running performance. J Strength Cond Res. Carbohydrate feeding during exercise. Coombes JSHKL.

The effectiveness of commercially available sports drinks. Wallis GA, Wittekind A. Is there a specific role for sucrose in sports and exercise performance?

Int J Sport Nutr Exerc Metab. Burke LM, Hawley JA, Schabort EJ, St Clair Gibson A, Mujika I, Noakes TD. Carbohydrate loading failed to improve km cycling performance in a placebo-controlled trial. Burke LM, Hawley JA, Angus DJ, Cox GR, Clark SA, Cummings NK, et al. Adaptations to short-term high-fat diet persist during exercise despite high carbohydrate availability.

Beelen M, Berghuis J, Bonaparte B, Ballak SB, Jeukendrup AE, van Loon LJC. Carbohydrate mouth rinsing in the fed state: lack of enhancement of time-trial performance.

Rollo I, Williams C. Influence of ingesting a carbohydrate-electrolyte solution before and during a 1-hour run in fed endurance-trained runners.

J Sports Sci. McGawley K, Shannon O, Betts J. Ingesting a high-dose carbohydrate solution during the cycle section of a simulated Olympic-distance triathlon improves subsequent run performance. Clarke ND, Maclaren DPM, Reilly T, Drust B. Carbohydrate ingestion and pre-cooling improves exercise capacity following soccer-specific intermittent exercise performed in the heat.

Eur J Appl Physiol. Ganio MS, Klau JF, Lee EC, Yeargin SW, McDermott BP, Buyckx M. Effect of various carbohydrate-electrolyte fluids on cycling performance and maximal voluntary contraction.

Flynn MG, Michaud TJ, Rodriguez-Zayas J, Lambert CP, Boone JB, Moleski RW. Effects of 4- and 8-h preexercise feedings on substrate use and performance. el-Sayed MS, Rattu AJ, Roberts I. Effects of carbohydrate feeding before and during prolonged exercise on subsequent maximal exercise performance capacity.

Int J Sport Nutr. Campbell C, Prince D, Braun M, Applegate E, Casazza GA. Carbohydrate-supplement form and exercise performance. Cox AJ, Pyne DB, Cox GR, Callister R, Gleeson M. Pre-exercise carbohydrate status influences carbohydrate-mediated attenuation of post-exercise cytokine responses.

Cox GR, Clark SA, Cox AJ, Halson SL, Hargreaves M, Hawley JA, et al. Daily training with high carbohydrate availability increases exogenous carbohydrate oxidation during endurance cycling. Hulston CJ, Jeukendrup AE. No placebo effect from carbohydrate intake during prolonged exercise.

Acker-Hewitt TL, Shafer BM, Saunders MJ, Goh Q, Luden ND. Independent and combined effects of carbohydrate and caffeine ingestion on aerobic cycling performance in the fed state. Baur DA, Schroer AB, Luden ND, Womack CJ, Smyth SA, Saunders MJ.

Glucose-fructose enhances performance versus isocaloric, but not moderate, glucose. Langenfeld ME, Seifert JG, Rudge SR, Bucher RJ.

Effect of carbohydrate ingestion on performance of non-fasted cyclists during a simulated mile time trial.

J Sports Med Phys Fitness. Nassif C, Gomes AR, Peixoto GHC, Chagas MH, Soares DD, Silami-Garcia E, et al. The effect of double--blind carbohydrate ingestion during 60 km of self-paced exercise in warm ambient conditions. PloS One. Article PubMed PubMed Central Google Scholar. van Essen M, Gibala MJ.

Failure of protein to improve time trial performance when added to a sports drink. Jeukendrup AE, Hopkins S, Aragon-Vargas LF, Hulston C. No effect of carbohydrate feeding on 16 km cycling time trial performance.

Angus DJ, Hargreaves M, Dancey J, Febbraio MA. Effect of carbohydrate or carbohydrate plus medium-chain triglyceride ingestion on cycling time trial performance.

Desbrow B, Anderson S, Barrett J, Rao E, Hargreaves M. Carbohydrate-electrolyte feedings and 1 h time trial cycling performance. PubMed Google Scholar. Hunter AM, St Clair Gibson A, Collins M, Lambert M, Noakes TD. Caffeine ingestion does not alter performance during a km cycling time-trial performance.

el-Sayed MS, Balmer J, Rattu AJ. Carbohydrate ingestion improves endurance performance during a 1 h simulated cycling time trial. Chambers ES, Bridge MW, Jones DA.

Carbohydrate sensing in the human mouth: effects on exercise performance and brain activity. J Physiol. Pottier A, Bouckaert J, Gilis W, Roels T, Derave W.

Mouth rinse but not ingestion of a carbohydrate solution improves 1-h cycle time trial performance. Scand J Med Sci Sports. Rollo I, Cole M, Miller R, Williams C. Influence of mouth rinsing a carbohydrate solution on 1-h running performance.

Lane SC, Bird SR, Burke LM, Hawley JA. Effect of a carbohydrate mouth rinse on simulated cycling time-trial performance commenced in a fed or fasted state. Carter JM, Jeukendrup AE, Jones DA. The effect of carbohydrate mouth rinse on 1-h cycle time trial performance.

Rollo I, Williams C, Gant N, Nute M. The influence of carbohydrate mouth rinse on self-selected speeds during a min treadmill run. Sinclair J, Bottoms L, Flynn C, Bradley E, Alexander G, McCullagh S, et al.

The effect of different durations of carbohydrate mouth rinse on cycling performance. Erickson MA, Schwarzkopf RJ, McKenzie RD. Effects of caffeine, fructose, and glucose ingestion on muscle glycogen utilization during exercise.

Pirnay F, Crielaard JM, Pallikarakis N, Lacroix M, Mosora F, Krzentowski G, et al. Fate of exogenous glucose during exercise of different intensities in humans. Costill DL, Bennett A, Branam G, Eddy D.

Glucose ingestion at rest and during prolonged exercise. Metabolism and performance following carbohydrate ingestion late in exercise. Coyle EF, Coggan AR, Hemmert MK, Ivy JL.

Muscle glycogen utilization during prolonged strenuous exercise when fed carbohydrate. Jeukendrup AE, Raben A, Gijsen A, Stegen JH, Brouns F, Saris WH, Wagenmakers AJ. Glucose kinetics during prolonged exercise in highly trained human subjects: effect of glucose ingestion.

Howlett K, Angus D, Proietto J, Hargreaves M. Effect of increased blood glucose availability on glucose kinetics during exercise. van Handel PJ, Fink WJ, Branam G, Costill DL. Fate of 14 C Glucose ingested during prolonged exercise. Bosch AN, Dennis SC, Noakes TD.

Influence of carbohydrate ingestion on fuel substrate turnover and oxidation during prolonged exercise. J Appl Physiol Bethesda, MD. CAS Google Scholar. Brouns F, Beckers E. Is the gut an athletic organ? Digestion, absorption and exercise.

Rowlands DS, Swift M, Ros M, Green JG. Composite versus single transportable carbohydrate solution enhances race and laboratory cycling performance.

Jentjens RL, Jeukendrup AE. High rates of exogenous carbohydrate oxidation from a mixture of glucose and fructose ingested during prolonged cycling exercise. Br J Nutr. Triplett D, Doyle JA, Rupp JC, Benardot D.

Wallis GA, Rowlands DS, Shaw C, Jentjens RLPG, Jeukendrup AE. Oxidation of combined ingestion of maltodextrins and fructose during exercise. Superior endurance performance with ingestion of multiple transportable carbohydrates. Download references. Paradoxically, carbohydrates are the preferred fuel during exercise of high intensity but are stored in extremely limited amounts in the body.

This storage form of carbohydrate, called glycogen, is found primarily in muscles and liver. The glycogen in the muscle is used directly by the muscle which is being exercised. There are two ways by which the athlete can manipulate the carbohydrate content of their diet to improve performance:.

How much carbohydrate is enough? We often express recommendations in terms of percentages of total calories. Most people can do this if they consume 3 grams of carbohydrate per pound of body weight. For example, a pound person who is cycling, say, miles per week would require approximately grams of carbohydrate daily.

This carbohydrate would provide calories. Good examples of high carbohydrate foods are breads, cereals, grains, pasta, vegetables and fruits. Each time you exercise muscle glycogen becomes depleted to some extent.

By providing high carbohydrate intake every day, it more likely that you will restore the carbohydrate which has been used, thereby allowing for another hard bout of training the following day. To avoid hypoglycemia or low blood sugar during exercise, carbohydrate should probably not be consumed within 1 hour of the start of exercise.

The best pre-game strategy is to eat a light meal which contains or so grams of carbohydrate hours prior to exercise, which is low in fat and high in fluids. Such a meal might look something like this:.