High protein intake along with paternal part-time employment is associated with higher body fat mass among girls from South China

PURPOSE

Protein intake has been suggested to be associated with body composition among western children. Our aim was to determine whether protein intake is associated with body composition among Chinese children and to investigate whether parental socioeconomic status modifies these associations.

METHODS

Cross-sectional data were collected from the baseline survey of an ongoing population-based prospective open cohort study conducted in 2013. In this survey, 2039 children in South China were recruited using cluster random sampling. Information of 1704 children (47% girls), aged 7-12 years from three primary schools (42 classes), on diet and anthropometry was included finally. Their daily protein intake was obtained by 3-day 24-h dietary recalls. Skinfold thickness, body height, and weight were measured to calculate percent body fat (%BF), fat mass index (FMI), and fat-free mass index (FFMI). Parental characteristics were collected by questionnaires.

RESULTS

Among girls, protein intake was positively associated with %BF and FMI [estimate (SE) for %BF: 0.007 (0.003), p = 0.04; for FMI: 0.092 (0.002), p = 0.03], adjusted for pubertal stage, breast-feeding, maternal overweight, carbohydrate intake, energy intake, and physical activity level. Furthermore, there was interaction between paternal occupation and the relations of dietary protein with %BF and FMI (p _{for interaction} ≤ 0.04). None of the associations between protein intake and %BF, FMI, or FFMI was found among boys.

CONCLUSIONS

Our data indicate that school-aged girls, but not boys, living in South China with higher dietary protein intake might have higher body fat mass, which could be modified by paternal occupation.

Weight loss achieved using an energy restriction diet with normal or higher dietary protein decreased the number of CD14++CD16+ proinflammatory monocytes and plasma lipids and lipoproteins in middle-aged, overweight, and obese adults

Monocytes are involved in immune responses, and specific monocyte subpopulations (MS) that express intermediate to high levels of CD16 are associated with obesity and cardiovascular events. Consuming high protein (HP) when dieting improves body composition and cardiometabolic health outcomes, but whether HP affects MS during weight loss remains unknown. We assessed the effect of HP on energy restriction (ER)-induced changes in MS in overweight and obese adults. The relations between MS and plasma lipids and lipoproteins were also examined. We hypothesized that, independent of protein intake, ER-induced weight loss would decrease the numbers of MS and that MS and plasma lipids and lipoproteins would be related. Thirty-two adults (age 52 ± 1 years, body mass index 31.3 ± 0.5 kg/m², means ± S.E.) consumed either a normal protein (n=18) or HP (n=14) (0.8 vs 1.5 g•kg^-1•d^-1 protein) ER diet (750-kcal/d [3138-kJ/d] deficit) for 16 weeks. The HP diet included 0.7 g•kg^-1•d^-1 of milk protein isolate. Fasting plasma lipids, lipoproteins, and the numbers of MS were analyzed. Over time, independent of protein intake, CD14⁺⁺CD16⁺ cell number decreased, whereas CD14^dimCD16⁺⁺, CD14⁺CD16⁺, and CD14⁺CD16^- cell numbers remained unchanged. CD14^dimCD16⁺⁺ cell number was negatively associated with total cholesterol (TC) and triglyceride, while CD14⁺⁺CD16⁺ cell number was positively associated with TC, low-density lipoprotein cholesterol (LDL), TC to high-density lipoprotein cholesterol (HDL) ratio, and LDL to HDL ratio. Weight loss achieved while consuming an ER diet with either normal or high protein may improve immunity by partially decreasing proinflammatory monocytes. Associations between MS and plasma lipids and lipoproteins are confirmed in overweight and obese adults.

Epithelial response to a high-protein diet in rat colon

Background

High-protein diets (HPD) alter the large intestine microbiota composition in association with a metabolic shift towards protein degradation. Some amino acid-derived metabolites produced by the colon bacteria are beneficial for the mucosa while others are deleterious at high concentrations. The aim of the present work was to define the colonic epithelial response to an HPD. Transcriptome profiling was performed on colonocytes of rats fed an HPD or an isocaloric normal-protein diet (NPD) for 2 weeks.

Results

The HPD downregulated the expression of genes notably implicated in pathways related to cellular metabolism, NF-κB signaling, DNA repair, glutathione metabolism and cellular adhesion in colonocytes. In contrast, the HPD upregulated the expression of genes related to cell proliferation and chemical barrier function. These changes at the mRNA level in colonocytes were not associated with detrimental effects of the HPD on DNA integrity (comet assay), epithelium renewal (quantification of proliferation and apoptosis markers by immunohistochemistry and western blot) and colonic barrier integrity (Ussing chamber experiments).

Conclusion

The modifications of the luminal environment after an HPD were associated with maintenance of the colonic homeostasis that might be the result of adaptive processes in the epithelium related to the observed transcriptional regulations.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-017-3514-z) contains supplementary material, which is available to authorized users.

Physical Activity Modifies the Association between Dietary Protein and Lean Mass of Postmenopausal Women

BACKGROUND

Maintenance of lean muscle mass and related strength is associated with lower risk for numerous chronic diseases of aging in women.

OBJECTIVE

Our aim was to evaluate whether the association between dietary protein and lean mass differs by physical activity level, amino acid composition, and body mass index categories.

DESIGN

We performed a cross-sectional analysis of a prospective cohort.

PARTICIPANTS/SETTING

Participants were postmenopausal women from the Women's Health Initiative with body composition measurements by dual-energy x-ray absorptiometry (n=8,298).

MAIN OUTCOME MEASURES

Our study measured percent lean mass, percent fat mass, and lean body mass index.

STATISTICAL ANALYSES PERFORMED

Linear regression models adjusted for scanner serial number, age, calibrated energy intake, race/ethnicity, neighborhood socioeconomic status, and recreational physical activity were used to determine the relationship between protein intake and body composition measures. Likelihood ratio tests and stratified analysis were used to investigate physical activity and body mass index as potential effect modifiers.

RESULTS

Biomarker-calibrated protein intake was positively associated with percent lean mass; women in the highest protein quintile had 6.3 percentage points higher lean mass than the lowest quintile (P<0.001). This difference rose to 8.5 percentage points for physically active women in the highest protein quintile (P_interaction=0.023). Percent fat mass and lean body mass index were both inversely related to protein intake (both P<0.001). Physical activity further reduced percent fat mass (P_interaction=0.022) and lean body mass index (P_interaction=0.011). Leucine intake was associated with lean mass, as were branched chain amino acids combined (both P<0.001), but not independent of total protein. All associations were observed for normal-weight, overweight, and obese women.

CONCLUSIONS

Protein consumption up to 2.02 g/kg body weight daily is positively associated with lean mass in postmenopausal women. Importantly, those that also engage in physical activity have the highest lean mass across body mass index categories.

The potential of blue lupins as a protein source, in the diets of laying hens

Layers diets typically contain 15–20% soya due to its high crude protein content (ca. 36%). Reliance on soya for protein can result in large increases in cost of feed due to the law of supply and demand as a global commodity. Lupin grains have high protein content (35–40%) but previous experience with white lupins has shown toxic effects in poultry due to high levels alkaloids and poor performance due to anti-nutritional Non-starch polysaccharides (NSP). Here blue lupins either processed or whole were trialled for their potential as a protein source. Point of lay chickens (64) at 16 weeks of age were weighed and allocated to 16 coops of four hens. Coops, as the experimental unit, were randomly allocated to four treatments: layers mash with soya (Control); or layers mash with 150 g of lupin/kg diet with the lupin either: whole (Whole); dehulled (Dehulled) or dehulled + a solid state fermentation enzyme extract (SSF; 150 g/tonne DM). All diets were ground and formulated to be balanced for energy, crude protein and essential amino acids using NIRS. No difference in growth rate, final hen weight, DM and water intake, eggs per day, mean egg weight, yellowness of yolk or chroma was found between treatments. There was a trend (P<0.1) for the SSF treatment to produce less heavy shells and a significant effect for the lupin treatments to have redder yolks (P<0.001). Fecal DM and bacterial counts were not different and there was no sign of enteritis or intestinal tissue hyperplasia from hen autopsies. Inclusion of blue lupins in the diet of laying hens at a rate of 150 g/kg DM resulted in no adverse effects in production or hen health and could be used as part of a balanced ration with inclusion of NSP degrading enzymes to reduce reliance on soya protein.

Di- and tripeptide transport in vertebrates: the contribution of teleost fish models

Solute Carrier 15 (SLC15) family, alias H⁺-coupled oligopeptide cotransporter family, is a group of membrane transporters known for their role in the cellular uptake of di- and tripeptides (di/tripeptides) and peptide-like molecules. Of its members, SLC15A1 (PEPT1) chiefly mediates intestinal absorption of luminal di/tripeptides from dietary protein digestion, while SLC15A2 (PEPT2) mainly allows renal tubular reabsorption of di/tripeptides from ultrafiltration, SLC15A3 (PHT2) and SLC15A4 (PHT1) possibly interact with di/tripeptides and histidine in certain immune cells, and SLC15A5 has unknown function. Our understanding of this family in vertebrates has steadily increased, also due to the surge of genomic-to-functional information from 'non-conventional' animal models, livestock, poultry, and aquaculture fish species. Here, we review the literature on the SLC15 transporters in teleost fish with emphasis on SLC15A1 (PEPT1), one of the solute carriers better studied amongst teleost fish because of its relevance in animal nutrition. We report on the operativity of the transporter, the molecular diversity, and multiplicity of structural-functional solutions of the teleost fish orthologs with respect to higher vertebrates, its relevance at the intersection of the alimentary and osmoregulative functions of the gut, its response under various physiological states and dietary solicitations, and its possible involvement in examples of total body plasticity, such as growth and compensatory growth. By a comparative approach, we also review the few studies in teleost fish on SLC15A2 (PEPT2), SLC15A4 (PHT1), and SLC15A3 (PHT2). By representing the contribution of teleost fish to the knowledge of the physiology of di/tripeptide transport and transporters, we aim to fill the gap between higher and lower vertebrates.

Evaluation of Body Weight, Body Condition, and Muscle Condition in Cats with Hyperthyroidism

Background

The contribution of fat loss versus muscle wasting to the loss of body weight seen in hyperthyroid cats is unknown.

Objectives

To investigate body weight, body condition score (BCS), and muscle condition score (MCS) in hyperthyroid cats.

Animals

Four hundred sixty‐two cats with untreated hyperthyroidism, 117 of which were reevaluated after treatment.

Methods

Prospective cross‐sectional and before–after studies. Untreated hyperthyroid cats had body composition evaluated (body weight, BCS, and MCS). A subset of these cats were reevaluated 3–12 months after treatment when euthyroid.

Results

Pretreatment body weight (median, 4.36 kg; IQR, 3.5 to 5.2 kg) was lower than premorbid weight (5.45 kg; IQR, 4.6 to 6.4 kg, P < .0001) recorded 1–2 years before diagnosis. 154 (35.3%) cats were thin or emaciated; 357 (77.3%) had loss of muscle mass. Cats showed increases in body weight (median, 4.1 kg to 5.0 kg), BCS (median, 3/5 to 3.5/5), and MCS (2/3 to 3/3) after treatment (P < .001), but mild‐to‐moderate muscle wasting persisted in 45% of treated cats.

Conclusions and Clinical Importance

Most hyperthyroid cats lose body weight but maintain an ideal or overweight BCS, with only a third being underweight. As in human hyperthyroid patients, this weight loss is associated with muscle wasting, which affects >75% of hyperthyroid cats. Successful treatment leads to weight gain and increase of BCS in most cats, but almost half fail to regain normal muscle mass.

Controversies in Veterinary Nephrology: Differing Viewpoints: Role of Dietary Protein in the Management of Feline Chronic Kidney Disease

The role of diet in management of chronic kidney disease (CKD) is important. There are different interpretations of the current knowledge on this topic. Neither clinical trials involving product testing, nor prospective research investigating dietary influences on cats with induced kidney disease provide guidance on the utility of specific nutritional strategies. Likewise, data derived from other species also has limitations. More research is needed to further our understanding of this topic. However, practical guidance from current knowledge for the management of individual patients can be utilized with success.

A practical approach to dietary interventions for nondialysis-dependent CKD patients: the experience of a reference nephrology center in Brazil

This paper describes the 30-year experience on nutritional management of non-dialysis dependent chronic kidney disease (CKD) patients in a public outpatient clinic located in the city of São Paulo, Brazil. A team of specialized dietitians in renal nutrition is responsible to provide individual dietary counseling for patients on stages 3 to 5 of CKD. Two different types of nutrition care protocols are employed depending on the level of renal function. For patients with CKD stage 3 a simplified nutritional assessment is performed and the main dietary focus is on the control of protein intake particularly from animal sources. A more complete nutritional assessment as well as a detailed dietary plan focusing not only on the control of protein but also on energy supply and on specific micronutrients is provided for patients on stages 4 or 5 of CKD. Practical approaches and tools used by the dietitians in our clinic for improving patient´s adherence to protein, sodium and potassium restriction while maintaining a healthy diet are described in detail in the sections of the article.

[Nutrition for diabetic patients]

Evidence demonstrates that medical diabetes treatment has to be accompanied by lifestyle modifications. Structured nutrition interventions and increased physical activity will help patients to normalise, respectively maintain their body weight. The main target of a diabetes therapy is aimed at achieving normal or nearly normal blood glucose levels. Reaching this goal may be facilitated by the following nutritional patterns: Using mainly carbohydrates from vegetables, whole grains, legumes and fruits, Restriction of mono- and disaccharides are often important factors in normalising body weight and blood glucose, Reduction of dietary fat could be indicated. However, the primary goal is the limitation of saturated fatty acids which to high percentage are consumed with animal products. There is not sufficient evidence to recommend a dietary protein consumption of more than 20% of energy intake. Individuals with diabetes should be aware of the importance of acquiring daily vitamin and mineral requirements. Natural food sources should be preferred.

In vitro influence of dietary protein and fructooligosaccharides on metabolism of canine fecal microbiota

Background

The present in vitro study investigated whether the utilization of fructooligosaccharides (FOS) may influence canine fecal microbial population in presence of diets differing in their protein content and digestibility. Fresh fecal samples were collected from five adult dogs, pooled, and incubated for 24 h with the undigested residue of three diets: 1, Low protein high digestibility diet (LP HD, crude protein (CP) 229 g/kg); 2, High protein high digestibility diet (HP HD, CP 304 g/kg); 3, High protein low digestibility diet (HP LD, CP 303 g/kg) that had been previously subjected to enzymatic digestion. In the in vitro fermentation study, there were six treatments: 1) LP HD; 2) HP HD 3) HP LD; 4) LP HD + FOS; 5) HP HD + FOS; 6) HP LD + FOS. Fructooligosaccharides were added at the final concentration of 1.5 g/L. Samples of fermentation fluid were collected at 6 and 24 h of incubation.

Results

Values of pH were reduced by FOS at 6 and 24 h (P < 0.001); conversely, low protein digestibility and high dietary protein level resulted in higher pH at both sampling times (P < 0.001). At 24 h, FOS lowered ammonia (−10 %; P < 0.001) and resulted (P < 0.05) in higher concentrations of total volatile fatty acids (VFA) (+43 %), acetic acid (+14 %), propionic acid (+75 %) and n-butyric acid (+372 %). Conversely, at 24 h, low protein digestibility resulted (P < 0.01) in lower concentrations of acetic acid (−26 %), propionic acid (−37 %) and total VFA (−21 %). Putrescine concentrations were increased at 6 and 24 h of fermentation by low protein digestibility (+21 and 22 %, respectively; P < 0.05) and FOS (+18 and 24 %, respectively; P < 0.01). After 24 h of fermentation, high dietary protein level resulted in lower counts of lactobacilli and enterococci (−0.5 and −0.7 log cells/mL, respectively; P < 0.05) whereas low protein digestibility tended to increase counts of C. perfringens (+0.2 log cells/mL; P = 0.07).

Conclusions

Results from the present study showed that diets rich in protein may exert negative influences on the canine intestinal ecosystem, slightly increasing the presence of ammonia and reducing counts of lactobacilli and enterococci. Moreover, the presence of poorly digestible protein resulted in lower concentrations of VFA. Conversely, administration of FOS may improve metabolism of canine intestinal microbiota, reducing ammonia concentrations and enhancing VFA production.

The Effects of Increased Protein Intake on Fullness: A Meta-Analysis and Its Limitations

BACKGROUND

Higher protein intake has been implicated in weight management because of its appetitive properties. However, the effects of protein intake on appetitive sensations such as fullness have not been systematically assessed. Meta-analysis is a useful technique to evaluate evidence of an intervention's effect on testable outcomes, but it also has important limitations.

OBJECTIVE

The primary aim of this study was to synthesize the available evidence on the effect of protein intake on fullness using a quantitative meta-analysis and a secondary directional analysis using the vote-counting procedure. A tertiary aim was to address limitations of meta-analyses as they pertain to findings from this meta-analysis.

DESIGN

We searched multiple databases for interventional studies that evaluated the effect of increased protein intake on fullness ratings. Inclusion criteria for both analyses were as follows: healthy human participants, preload studies that utilized intact dietary protein, delivery of protein load orally, and studies reporting fullness as an outcome. For the meta-analysis, an additional criterion was that the studies also needed to report 2- to 4-hour area under the curve value for fullness.

RESULTS

Five studies met all criteria for the meta-analysis. Twenty-eight studies met all criteria for the directional analysis. The meta-analysis indicated higher protein preloads have a greater effect on fullness than lower protein preloads (overall effect estimate: 2,435.74 mm.240 min, (95% CI 1,375.18 to 3,496.31 mm.240 min; P<0.0001). The directional analysis also revealed a positive effect on fullness with higher protein preloads (P<0.01). Many related scientifically rigorous studies were excluded from the analysis because analytical criteria required a narrowly focused research question.

CONCLUSIONS

The present analyses show that higher protein preloads increase fullness ratings more than lower protein preloads under tightly defined conditions. Extrapolation of findings to common conditions outside the specified criteria of this analysis must be made cautiously, as must speculation about the influence of fullness sensations on ingestive behavior, body weight, and various health outcomes.

Distinct physiological, plasma amino acid, and liver transcriptome responses to purified dietary beef, chicken, fish, and pork proteins in young rats

SCOPE

We report on the impact of purified dietary meat proteins from four species on plasma insulin, lipid and amino acid (AA) concentrations, and hepatic transcriptome (RNA-sequencing).

METHODS AND RESULTS

Young rats received semi-synthetic diets for 1 wk that differed only regarding protein source; casein (reference) was replaced by beef, chicken, fish, or pork proteins. Compared to casein, all proteins, except pork, increased total plasma AA concentrations. Pork protein reduced adipose tissue mass and liver triacylglycerol, which was accompanied by increased plasma triacylglycerol concentrations. Plasma cholesterol was reduced by fish protein. The number of differentially expressed genes ranged between 609 (pork) and 1258 (chicken); on average one-third of the changes were specific for each meat protein. Pathway responses were most similar for beef and chicken, followed by pork and fish. Although the extent varied, all meat proteins induced mRNA translation, antigen processing/presentation, intracellular vesicular trafficking, and oxidoreductive-transformation pathways, and suppressed signal-transduction (Notch, TGFB/SMAD, insulin) and mitochondrial biogenesis pathways. Lipid- and AA-metabolic pathways were repressed, except by pork. AA-transport pathways were induced by beef and fish only, and complement/coagulation-pathways were suppressed by chicken and beef. Fish suppressed nuclear-transport and cofactor metabolism.

CONCLUSION

To conclude, short-term feeding of different meat proteins resulted in distinct physiological and transcriptome changes in young rats.

The impact of low-protein high-carbohydrate diets on aging and lifespan

Most research on nutritional effects on aging has focussed on the impact of manipulating single dietary factors such as total calorie intake or each of the macronutrients individually. More recent studies using a nutritional geometric approach called the Geometric Framework have facilitated an understanding of how aging is influenced across a landscape of diets that vary orthogonally in macronutrient and total energy content. Such studies have been performed using ad libitum feeding regimes, thus taking into account compensatory feeding responses that are inevitable in a non-constrained environment. Geometric Framework studies on insects and mice have revealed that diets low in protein and high in carbohydrates generate longest lifespans in ad libitum-fed animals while low total energy intake (caloric restriction by dietary dilution) has minimal effect. These conclusions are supported indirectly by observational studies in humans and a heterogeneous group of other types of interventional studies in insects and rodents. Due to compensatory feeding for protein dilution, low-protein, high-carbohydrate diets are often associated with increased food intake and body fat, a phenomenon called protein leverage. This could potentially be mitigated by supplementing these diets with interventions that influence body weight through physical activity and ambient temperature.

Effects of the dietary protein level on the microbial composition and metabolomic profile in the hindgut of the pig

The aim of this study was to investigate the effects of a long-term low protein diet on the microbial composition and metabolomic profile in the hindgut of the pig. Thirty-six Duroc × Landrace × Large White growing barrows (70 days of age, 23.57 ± 1.77 kg) were randomly allocated to normal protein diet (NP) and low protein diet (LP) groups using a randomized block design. At the age of 170 days, the digesta in the hindguts of the pigs were collected for microbial and metabolomic analysis. The results showed that there were no significant differences in the average daily gain, average daily feed intake, or feed:gain ratio between the NP and LP groups. The concentrations of isobutyrate, isovalerate, and branched-chain fatty acids (BCFAs)/short-chain fatty acids (SCFAs) in the cecum decreased with the reduction of dietary protein. Pyrosequencing of the V1-V3 region of the 16S rRNA genes showed that LP diet significantly decreased the relative abundance of Lactobacillus in the cecum, and Streptococcus in the colon; however, the relative abundance of Prevotella and Coprococcus in the LP group was significantly higher than in the NP group in the cecum, and Sarcina, Peptostreptococcaceae incertae sedis, Mogibacterium, Subdoligranulum, and Coprococcus was higher in the colon. The gas chromatography-mass spectrometry (GC-MS) analysis showed that the dietary protein level mainly affected phenylalanine metabolism; glycine, serine, and threonine metabolism; the citrate cycle; pyruvate metabolism; and the alanine, aspartate, and glutamate metabolism. Moreover, the correlation analysis of the combined datasets revealed some potential relationships between the colonic metabolites and certain microbial species. These results suggest that a low protein diet may modulate the microbial composition and metabolites of the hindgut, without affecting the growth performance of pigs; however, potential roles of this modulation to the health of pigs remains unknown.

Effects of protein sources and levels in antibiotic-free diets on diarrhea, intestinal morphology, and expression of tight junctions in weaned piglets

This study examined effects of dietary protein sources and levels on intestinal health of 21 to 35 d-old weaned piglets fed antibiotics-free diets. A total of 150 weaned piglets (21 d of age) were allotted to 5 dietary treatment groups. Diets were formulated, based on corn-soybean meal, with different protein sources (fish meal and soy protein concentrate) to provide different dietary CP levels. Piglets within 5 dietary treatments were fed diets as follows, respectively: 1) control diet of 17% CP (control); 2) 19% CP diets formulated with more soy protein concentrate (SPC19); 3) fish meal (FM19); 4) 23.7% CP diets formulated with more soy protein concentrate (SPC23); 5) fish meal (FM23). The results showed that piglets from control group had higher ADG and lower incidence of diarrhea compared with those of other groups (P < 0.05). The incidence of diarrhea of piglets in FM19 group was lower than those from SPC23 group and FM23 group (P < 0.05). With the higher CP levels, villous height and villous height to crypt depth ratio of piglets in the duodenum and jejunum were decreased (P < 0.05), but crypt depth was increased (P < 0.05). Comparing control group and other groups, we found the expression of inflammatory cytokines interleukin-1β (IL-1β) and interferon-γ (IFN-γ) were increased (P < 0.05) in the jejunum and colon of piglets, as did cystic fibrosis transmembrane conductance regulators (CFTR) in the distal colon. The relative transcript abundance of Zonula occludens-1 (ZO-1) in the jejunum, and occludin in the jejunum and ileum of piglets fed 23.7% CP diets were reduced compared with those fed control diet (P < 0.05). In conclusion, the 17% CP diet without in-feed antibiotics helped improve growth performance and relief of diarrhea of 21 to 35 d-old weaned piglets. Dietary CP level, rather than its source (either fish meal or soy protein concentrate), has more significant impacts on the growth performance and intestinal health of 21 to 35 d-old weaned piglets when fed antibiotics-free diets.

Protein intake in early childhood and cardiometabolic health at school age: the Generation R Study

Purpose

High protein intake in infancy has been linked to obesity. We aimed to examine the associations of protein intake in early childhood with cardiovascular and metabolic outcomes at school age.

Methods

This study was performed in 2965 children participating in a population-based prospective cohort study. Protein intake at 1 year was assessed with a food frequency questionnaire and was adjusted for energy intake. At the children’s age of 6 years, we measured their body fat percentage (BF%), blood pressure (BP), and insulin, HDL cholesterol, and triglyceride serum levels. These measures were incorporated into a cardiometabolic risk factor score, using age- and sex-specific SD scores.

Results

In covariate-adjusted models, higher protein intake was associated with a higher BF%, lower diastolic BP, and lower triglyceride levels. We observed a significant interaction of protein intake with child sex on metabolic outcomes. Stratified analyses showed that protein intake was positively associated with BF% [0.07 SD (95 % CI 0.02; 0.13) per 10 g/day] and insulin levels in girls, but not in boys. In boys, but not in girls, higher protein intake was associated with lower triglyceride levels [−0.12 SD (95 % CI −0.20; −0.04) per 10 g/day] and a lower cardiometabolic risk factor score. Protein intake was not consistently associated with systolic BP or HDL cholesterol levels.

Conclusion

Protein intake in early childhood was associated with a higher BF% and higher insulin levels at 6 years in girls and with lower triglyceride levels in boys. Further studies are needed to explore these sex differences and to investigate whether the observed changes persist into adulthood.

Electronic supplementary material

The online version of this article (doi:10.1007/s00394-015-1026-7) contains supplementary material, which is available to authorized users.

Co-dependence of genotype and dietary protein intake to affect expression on amino acid/peptide transporters in porcine skeletal muscle

A total of 96 barrows (48 pure-bred Bama mini-pigs representing fatty genotype, and 48 Landrace pigs representing lean genotype) were randomly assigned to either a low- or adequate-protein treatment diet. The experimental period commenced at 5 weeks of age and extended to the finishing period. After euthanasia, blood and skeletal muscle samples were collected from pigs at the nursery, growing, and finishing phases. Our results indicate that the concentrations of free AAs in the plasma and muscle decreased as the age of the pigs increased. In addition, a strain × growth phase interaction (P < 0.05) was observed for the free AA pool in the plasma and muscle. The low-protein diet upregulated (P < 0.05) the mRNA levels for T1R1/T1R3 involved in glutamate binding, but downregulated (P < 0.05) the mRNA levels for PAT1, PAT2, and ASCT2, which transport neutral AAs into muscles. Bama mini-pigs had higher (P < 0.05) mRNA levels for LAT1, SNAT2, and EAAC1, but a lower (P < 0.05) mRNA level for PepT1, compared with Landrace pigs. Collectively, our findings indicate that adequate provision of dietary protein plays an important role in regulating profiles of free AA pools and expression of key AA/peptide transporters/transceptors in a genotype- and tissue-specific manner.

The effects of dietary protein and amino acids on skeletal metabolism

Dietary protein is required for optimal skeletal growth and maturation. Although Recommended Dietary Allowances (RDAs) exist for global dietary protein intake, the level and sources of dietary protein that are optimal for skeletal health over the life continuum have not been established. This is partly due to the difficulty in quantifying the effects of variable levels of a nutrient's intake over a lifetime as well as the complex nature of the relationships between dietary protein and calcium economy. Areas of current uncertainty include the precise source and amount of dietary protein required for optimal skeletal accretion and maintenance of skeletal mass, as well as the site-specific effects of dietary protein. The cellular and molecular mechanisms that underpin the actions of dietary protein on mineral metabolism and skeletal homeostasis remain unclear. This review attempts to summarize recent data bearing on these questions.

Dietary ratio of animal:plant protein is associated with 24-h urinary iodine excretion in healthy school children

Adequate dietary iodine intake in children is essential for optimal physical and neurological development. Whether lower dietary animal food and salt intake may adversely affect iodine status is under discussion. We examined the association between dietary animal:plant protein ratio with 24-h urinary iodine excretion (24-h UI, μg/d), and whether this is modified by salt intake. A 24-h UI was measured in 1959 24-h urine samples from 516 6- to 12-year-old participants of the Dortmund Nutritional and Anthropometric Longitudinally Designed Study. Parallel 3 d weighed food records were used to estimate dietary intakes. Protein sources were classified as dairy, animal and plant. A repeated-measures regression model (PROC MIXED) was used to analyse the effect of animal:plant protein ratios on 24-h UI.

ANIMAL

plant protein ratios ranged from 0.5 (95 % CI 0.4, 0.6) to 1.6 (95 % CI 1.4, 1.9) (lowest and highest quartile). After adjustment for total energy intake, main dietary iodine sources (dairy and salt intake), and further covariates, the inter-individual variation in animal:plant protein ratio was significantly associated with variation in 24-h UI. One unit higher animal:plant protein ratio predicted 6 μg/d higher 24-h UI (P= 0.002) in boys and 5 μg/d (P= 0.03) in girls. This relationship was partially mediated by a higher salt intake at higher animal:plant protein ratios. These results suggest that lower consumption of animal protein is associated with a small decline in iodine excretion, partially mediated by decreased salt intake. Because limited salt and increased intake of plant-based foods are part of a preferable healthy food pattern, effective nutrition political strategies will be required in the future to ensure appropriate iodine nutrition in adherent populations.

Curcumin ameliorates the tumor-enhancing effects of a high-protein diet in an azoxymethane-induced mouse model of colon carcinogenesis

An increasing number of reports suggest that a high-protein diet (HPD) is associated with an increased risk for colorectal cancer (CRC). One of the proposed mechanisms is that an HPD increases the delivery of protein to the colon and generates various toxic metabolites that contribute to colon carcinogenesis. Curcumin was shown to exert significant preventive properties against CRC. We therefore hypothesized that curcumin can reverse the tumor-enhancing effects of an HPD. This study examined the effects of curcumin on the development of azoxymethane (AOM)-induced colorectal tumors in HPD-fed mice. A total of 30 female Balb/c mice were randomly divided into 3 groups: those fed a normal diet (20% casein), those fed an HPD (HPD; 50% casein), and those fed an HPD supplemented with curcumin (HPDC; 0.02% curcumin). The mice were subjected to an AOM-dextran sodium sulfate colon carcinogenesis protocol. Mice in the HPDC group exhibited a significant (40%) reduction in colorectal tumor multiplicity when compared with those in the HPD group. The expression of colonic inflammatory proteins (cyclooxygenase-2 and inducible nitric oxide synthase), the levels of plasma inflammatory markers (nitric oxide and tumor necrosis factor-α), fecal ammonia, short- and branched-chain fatty acid levels, and the rate of colonocyte proliferation were significantly lower in the HPDC than the HPD group. In conclusion, curcumin inhibited the development of colorectal tumors in an AOM-induced mouse model of colon carcinogenesis by attenuating colonic inflammation, proliferation, and toxic metabolite production. Curcumin might be useful in the chemoprevention of CRC in individuals consuming an HPD.

Bone Mineral Density and Protein-Derived Food Clusters from the Framingham Offspring Study

BACKGROUND

Dietary protein is beneficial to bone health; however, dietary patterns of protein intake and their relationship with bone mineral density (BMD) have not been evaluated.

OBJECTIVE

To examine the relationship of dietary protein food clusters with BMD at the femoral neck, trochanter, total femur, and lumbar spine among middle-aged and older men and women.

DESIGN

Cross-sectional study.

PARTICIPANTS AND SETTING

Two thousand seven hundred fifty-eight community-dwelling individuals from the Framingham Offspring Study.

METHODS

BMD was measured by Lunar DPX-L (Lunar Radiation Corporation) in 1996-2001. Dietary intakes were estimated using the Willett food frequency questionnaire in either 1995-1998 or 1998-2001, and the exam closest to a participant's BMD measurement was used. Cluster analysis (FASTCLUS procedure, k-means method) was used to classify participants into groups, determined by major sources of protein. Generalized linear regression was used to compare adjusted least-squares mean BMD across protein food clusters for all pairwise comparisons.

RESULTS

From 2,758 participants (44% men; mean age 61±9 years, range=29 to 86 years), five protein food clusters were identified (chicken, fish, processed foods, red meat, and low-fat milk). Three of these food clusters showed associations with BMD. The red meat protein food cluster presented with significantly lower femoral neck BMD compared with the low-fat milk cluster (red meat 0.898±0.005 g/cm(2) vs low-fat milk 0.919±0.007 g/cm(2); P=0.04). Further, the processed foods protein cluster presented with significantly lower femoral neck BMD compared with the low-fat milk cluster (processed foods 0.897±0.004 g/cm(2) vs low-fat milk 0.919±0.007 g/cm(2); P=0.02). A similar, yet nonsignificant, trend was observed for other BMD sites examined.

CONCLUSIONS

Diets with the greatest proportion of protein intake from red meat and processed foods may not be as beneficial to the skeleton compared with dietary patterns where the highest proportion of protein is derived from low-fat milk.

The association of plasma IGF-I with dietary, lifestyle, anthropometric, and early life factors in postmenopausal women

OBJECTIVE

Higher circulating concentrations of insulin like growth factor (IGF-I) are associated with an increased risk of breast cancer. The objective of this study was to investigate associations between circulating IGF-I concentrations and dietary factors (intakes of protein, dairy protein, and alcohol), lifestyle factors (smoking and HT use), anthropometric indices (height and adiposity) and factors in early life (birth weight, having been breastfed, body size at age 10, and at age 20) in postmenopausal women in the UK.

DESIGN

An analysis of plasma IGF-I concentrations (measured by immunoassay) in 1883 postmenopausal women. Multivariate analysis was used to examine correlates of plasma IGF-I concentrations.

RESULTS

Women in the highest quintile of total protein and dairy protein intakes had, respectively, 7.6% and 5.5% higher plasma IGF-I concentrations than women in the lowest quintile (p trend <0.05 for both). Other factors significantly (p<0.05) associated with reduced IGF-I concentrations were: consuming 14 or more vs 3-7 alcoholic drinks per week (8.8% lower IGF-I); current vs non-current HT users (9.9% lower IGF-I); current use of oestrogen alone vs oestrogen+progestagen (16.9% lower IGF-I); obese vs overweight (6.8% lower IGF-I); and women who reported wearing larger vs smaller clothes sizes at age 20 (4.9% lower IGF-I).

CONCLUSIONS

This study in post-menopausal women identified several potentially modifiable determinants of circulating IGF-I concentrations. There is now strong evidence from this and other studies that IGF-I concentrations are associated with dietary protein intakes.

Association between post-dinner dietary intakes and nocturnal hypoglycemic risk in adult patients with type 1 diabetes

AIMS

To describe (i) current bedtime nutritional practices and (ii) the association between post-dinner dietary intake and the occurrence of non-severe nocturnal hypoglycemia (NH) in real-life conditions among adult patients with type 1 diabetes using insulin analogs.

METHODS

One hundred adults (median [interquartile range]: age 46.4 [36.0-55.8] years, HbA1c 7.9 [7.3-8.6] % (63 [56-70] mmol/mol)) using multiple daily injections (n=67) or insulin pump (n=33) wore a blinded continuous glucose monitoring system and completed a food diary for 72-h.

RESULTS

NH occurred on 28% of 282 nights analyzed. (i) Patients reported post-dinner dietary intakes on 63% of the evenings. They injected rapid-acting insulin boluses on 64 occasions (23% of 282 evenings). These insulin boluses were mostly injected with (n=37) dietary intakes. (ii) Post-dinner dietary intake was not associated with NH occurrence in univariate analyses. In multivariate analyses, the injection of rapid-acting insulin modulated the association between post-dinner dietary intake and NH: with insulin, post-dinner carbohydrate intake was positively associated with NH (odds ratio (OR): 1.16 [95% confidence interval, CI: 1.04-1.29] per 5g increase, p=0.008); without insulin, post-dinner protein intake was inversely associated with NH occurrence (OR [95% CI]: 0.88 [0.78-1.00] per 2g increase, p=0.048).

CONCLUSIONS

NH remains frequent in adults with type 1 diabetes. There is a complex relationship between post-dinner dietary intake and NH occurrence, including the significant role of nutrient content and rapid-acting insulin injection that requires further investigation.

A protein-enriched low glycemic index diet with omega-3 polyunsaturated fatty acid supplementation exerts beneficial effects on metabolic control in type 2 diabetes

AIMS

The current study aims to investigate practicability and effects of a combined dietary intervention with increased relative protein content supplemented with omega-3 polyunsaturated fatty acids (PUFA) on metabolic control and inflammatory parameters in a real life situation in type 2 diabetes patients.

METHODS

In this observational study we advised thirty mostly obese patients with type 2 diabetes to follow a protein-enriched diet with carbohydrates of low glycemic index (low GI) and moderate fat reduction supplemented with omega-3 PUFA for 24 weeks. Primary efficacy parameter was the change in HbA1c; secondary parameters included changes in systemic inflammation (measured by ultrasensitive C-reactive protein, usCRP), body weight, waist circumference, fat mass. The study is registered at clinicaltrials.gov (NCT01474603).

RESULTS

The dietary intervention significantly reduced the primary efficacy variable HbA1c from a baseline value of 63±11mmol/mol to 59±14mmol/mol (P=0.033) and 56±12mmol/mol (P=0.001) after 12 and 24 weeks, respectively. In addition, usCRP decreased significantly at 24 weeks (P=0.039). Waist circumference, an important indicator for cardiometabolic-risk and silent inflammation, decreased from baseline 116.0±14.1cm to 114.9±13.5cm (P=0.019), 114.0±14.4cm (P=0.001), and 112.7±13.4cm (P=0.049), after 3, 12 and 24 weeks, respectively.

CONCLUSION

Counseling a protein enriched and low glycemic index diet supplemented with long-chain omega-3 PUFA in a real-life clinical setting improves glycemic control and also reduces waist circumference and silent inflammation in overweight or obese patients with type 2 diabetes.

Relevance of dietary protein concentration and quality as risk factors for the formation of calcium oxalate stones in cats

The role of dietary protein for the development of feline calcium oxalate (CaOx) uroliths has not been conclusively clarified. The present study evaluated the effects of a varying dietary protein concentration and quality on critical indices for the formation of CaOx uroliths. Three diets with a high protein quality (10–11 % greaves meal/diet) and a varying crude protein (CP) concentration (35, 44 and 57 % in DM) were compared. Additionally, the 57 % CP diet was compared with a fourth diet that had a similar CP concentration (55 % in DM), but a lower protein quality (34 % greaves meal/diet). The Ca and oxalate (Ox) concentrations were similar in all diets. A group of eight cats received the same diet at the same time. Each feeding period was divided into a 21 d adaptation period and a 7 d sampling period to collect urine. There were increases in urinary volume, urinary Ca concentrations, renal Ca and Ox excretion and urinary relative supersaturation (RSS) with CaOx with increasing dietary protein concentrations. Urinary pH ranged between 6·34 and 6·66 among all groups, with no unidirectional effect of dietary protein. Lower renal Ca excretion was observed when feeding the diet with the lower protein quality, however, the underlying mechanism needs further evaluation. In conclusion, although the observed higher urinary volume is beneficial, the increase in urinary Ca concentrations, renal Ca and Ox excretion and urinary RSS CaOx associated with a high-protein diet may be critical for the development of CaOx uroliths in cats.

Associations of plant and animal protein intake with 5-year changes in blood pressure: the Zutphen Elderly Study

BACKGROUND AND AIM

The aim of the present study was to investigate the association of plant and animal protein intake with 5-year changes in blood pressure (BP) level.

METHODS AND RESULTS

Analyses were based on 702 observations of 272 men participating in the Zutphen Elderly Study. Men did not use antihypertensive medication and were initially free of cardiovascular disease, diabetes mellitus and cancer. Physical and dietary examinations were performed in 1985, 1990, 1995, and 2000. Diet was assessed using the cross-check dietary history method. Men were categorised into tertiles according to their plant and animal protein intake. BP was measured twice at each examination. The associations of plant and animal protein intake with 5-year changes in BP level were investigated by a random intercept model with first-order autoregressive (AR [1]) serial correlation and a nugget effect. Adjustments were made for age, examination year, BMI, socioeconomic status, smoking, physical activity, prescribed diet, alcohol consumption and intake of energy and nutrients. In 1985, men were 70.1 ± 4.6 years old and had a mean BP of 147/84 mmHg. Mean protein intake was 15 en%, of which one-third consisted of plant protein. The higher-intake tertiles of plant protein intake were associated with a mean 5-year change of -2.9 mmHg (95% CI: -5.6, -0.2) systolic and -1.7 mmHg (95% CI: -3.2, -0.2) diastolic, compared with the lowest-intake tertile. No associations were observed for animal protein intake.

CONCLUSION

Intake of plant protein, but not animal protein, was inversely associated with 5-year changes in BP level in elderly men.

High dietary protein restores overreaching induced impairments in leukocyte trafficking and reduces the incidence of upper respiratory tract infection in elite cyclists

The present study examined whether a high protein diet prevents the impaired leukocyte redistribution in response to acute exercise caused by a large volume of high-intensity exercise training. Eight cyclists (VO2max: 64.2±6.5mLkg(-1)min(-1)) undertook two separate weeks of high-intensity training while consuming either a high protein diet (3gkg(-1)proteinBM(-1)day(-1)) or an energy and carbohydrate-matched control diet (1.5gkg(-1)proteinBM(-1)day(-1)). High-intensity training weeks were preceded by a week of normal-intensity training under the control diet. Leukocyte and lymphocyte sub-population responses to acute exercise were determined at the end of each training week. Self-reported symptoms of upper-respiratory tract infections (URTI) were monitored daily by questionnaire. Undertaking high-intensity training with a high protein diet restored leukocyte kinetics to similar levels observed during normal-intensity training: CD8(+) TL mobilization (normal-intensity: 29,319±13,130cells/μL×∼165min vs. high-intensity with protein: 26,031±17,474cells/μL×∼165min, P>0.05), CD8(+) TL egress (normal-intensity: 624±264cells/μL vs. high-intensity with protein: 597±478cells/μL, P>0.05). This pattern was driven by effector-memory populations mobilizing (normal-intensity: 6,145±6,227cells/μL×∼165min vs. high-intensity with protein: 6,783±8,203cells/μL×∼165min, P>0.05) and extravastating from blood (normal-intensity: 147±129cells/μL vs. high-intensity with protein: 165±192cells/μL, P>0.05). High-intensity training while consuming a high protein diet was associated with fewer symptoms of URTI compared to performing high-intensity training with a normal diet (P<0.05). To conclude, a high protein diet might reduce the incidence of URTI in athletes potentially mediated by preventing training-induced impairments in immune-surveillance.

The impact of dietary methionine restriction on biomarkers of metabolic health

Calorie restriction without malnutrition, commonly referred to as dietary restriction (DR), results in a well-documented extension of life span. DR also produces significant, long-lasting improvements in biomarkers of metabolic health that begin to accrue soon after its introduction. The improvements are attributable in part to the effects of DR on energy balance, which limit fat accumulation through reduction in energy intake. Accumulation of excess body fat occurs when energy intake chronically exceeds the energy costs for growth and maintenance of existing tissue. The resulting obesity promotes the development of insulin resistance, disordered lipid metabolism, and increased expression of inflammatory markers in peripheral tissues. The link between the life-extending effects of DR and adiposity is the subject of an ongoing debate, but it is clear that decreased fat accumulation improves insulin sensitivity and produces beneficial effects on overall metabolic health. Over the last 20 years, dietary methionine restriction (MR) has emerged as a promising DR mimetic because it produces a comparable extension in life span, but surprisingly, does not require food restriction. Dietary MR also reduces adiposity but does so through a paradoxical increase in both energy intake and expenditure. The increase in energy expenditure fully compensates for increased energy intake and effectively limits fat deposition. Perhaps more importantly, the diet increases metabolic flexibility and overall insulin sensitivity and improves lipid metabolism while decreasing systemic inflammation. In this chapter, we describe recent advances in our understanding of the mechanisms and effects of dietary MR and discuss the remaining obstacles to implementing MR as a treatment for metabolic disease.

Food protein-induced proctocolitis: Is this allergic disorder a reality or a phantom in neonates?

The etiology of small and fresh rectal bleeding in neonates who are not sick is usually unknown; the only known cause is food protein-induced proctocolitis (FPIPC). It has been recently reported that FPIPC is a rare cause of rectal bleeding in newborns, and most cases have been proved to be due to idiopathic neonatal transient colitis. A recommended strategy for diagnosing suspected FPIPC in neonates is as follows. During the early stage, the etiology of small and fresh rectal bleeding in an otherwise healthy newborn need not be studied through extensive investigations. In patients showing continued bleeding even after 4 days, sigmoidoscopy and rectal mucosal biopsy may be performed. Even if mucosal histological findings indicate a diagnosis of FPIPC, further oral food elimination and challenge tests must be performed sequentially to confirm FPIPC. Food elimination and challenge tests should be included in the diagnostic criteria of FPIPC.

Diet-induced weight loss: the effect of dietary protein on bone

High-protein (>30% of energy from protein or >1.2 g/kg/day) and moderately high-protein (22% to 29% of energy from protein or 1.0 to 1.2 g/kg/day) diets are popular for weight loss, but the effect of dietary protein on bone during weight loss is not well understood. Protein may help preserve bone mass during weight loss by stimulating insulin-like growth factor 1, a potent bone anabolism stimulator, and increasing intestinal calcium absorption. Protein-induced acidity is considered to have minimal effect on bone resorption in adults with normal kidney function. Both the quantity and predominant source of protein influence changes in bone with diet-induced weight loss. Higher-protein, high-dairy diets may help attenuate bone loss during weight loss.

Regional, but not total, body composition changes in overweight and obese adults consuming a higher protein, energy-restricted diet are sex specific

Secondary analyses of data from 2 studies were used to assess the effects of protein intake and sex on diet-induced changes in body composition. The primary hypothesis was that the changes of body composition via energy restriction (ie, lean body mass [LBM], fat mass [FM], and bone) would be sex and diet specific. For 12 weeks, 43 male (study 1) and 45 female (study 2) overweight and obese adults consumed an energy-deficit diet (750 kcal/d less than energy needs) containing either 0.8 (normal protein [NP], 21 men and 23 women) or 1.4 g protein∙kg(-1)∙d(-1) (high protein [HP], 22 men and 22 women). Body composition measurements were performed at preintervention and postintervention. Over time, all research participants lost weight, LBM, and FM. Independent of protein intake, the men lost more LBM in the trunk (-0.9 vs -0.5 kg) and less in the legs (-1.5 vs -1.1 kg) compared with the women (P < .05). Independent of sex, the HP group lost less LBM in the trunk and legs than the NP group. These sex and protein intake responses resulted in the NP men losing the most LBM in the legs and the NP women losing the most LBM in the trunk. Over time, men lost more FM (-5.0 vs -3.9 kg) from the trunk and less from legs (-1.7 vs -2.1 kg) than women (P < .05), which resulted in a greater decrease of the android-to-gynoid fat ratio for the men. Protein intake did not influence these sex-specific responses or have any independent effects on changes in FM. In addition, protein intake did not influence bone mineral density responses over time; bone mineral density was reduced in women, but not in men. These findings indicate that higher protein intake during weight loss promotes the retention of LBM in both the trunk and legs despite the sex-specific changes in these body regions.

Differential modulation of the functionality of white adipose tissue of obese Zucker (fa/fa) rats by the type of protein and the amount and type of fat

Recent evidence indicates that several metabolic abnormalities developed during obesity are associated with the presence of dysfunctional adipose tissue. Diet is a key factor that modulates several functions of adipose tissue; however, each nutrient in the diet produces specific changes. Thus, the aim of this work was to study the effect of the interaction of the type (coconut or soybean oil) and amount (5% or 10%) of fat with the type of dietary protein (casein or soy protein) on the functionality of white adipose tissue of Zucker (fa/fa) rats. The results showed that soybean oil reduced adipocyte size and decreased esterified saturated fatty acids in white adipose tissue. Excess dietary fat also modified the composition of esterified fatty acids in white adipose tissue, increased the secretion of saturated fatty acids to serum from white adipose tissue and reduced the process of fatty acids re-esterification. On the other hand, soy protein sensitized the activation of the hormone-sensitive lipase by increasing the phosphorylation of this enzyme (Ser 563) despite rats fed soy protein were normoglucagonemic, in contrast with rats fed casein that showed hyperglucagonemia but reduced hormone-sensitive lipase phosphorylation. Finally, in white adipose tissue, the interaction between the tested dietary components modulated the transcription/translation process of lipid and carbohydrate metabolism genes via the activity of the PERK-endoplasmic reticulum stress response. Therefore, our results showed that the type of protein and the type and amount of dietary fat selectively modify the activity of white adipose tissue, even in a genetic model of obesity.

The mTOR Pathway and the Role of Energy Balance Throughout Life in Colorectal Cancer Etiology and Prognosis: Unravelling Mechanisms Through a Multidimensional Molecular Epidemiologic Approach

Timing of exposure to lifestyle factors that influence energy balance may differentially affect colorectal cancer (CRC) risk and prognosis. Caloric restriction in youth and short stature, as markers of early-life exposures, have shown to decrease CRC risk, whereas large body size and low physical activity levels in adulthood are established risk factors for CRC. Regarding prognosis, overweight, sarcopenia, and their co-occurrence (sarcopenic obesity) may negatively influence the health and quality of life of CRC survivors. There is mechanistic support for disruption of the mammalian target of rapamycin (mTOR) pathway as an underlying mechanism possibly driving these associations, because mTOR integrates signals from growth factors, nutrients, mutagens, and hormones to induce cell proliferation, resistance to apoptosis, and autophagy. However, epidemiologic evidence connecting mTOR to energy-balance-related CRC throughout the lifespan is scarce. This perspective proposes how multidimensional molecular epidemiologic studies can shed light on the etiology and prognosis of energy-balance-related CRC.