There is a strong relationship between stress and the intake of calorically-dense palatable food. Additionally, intake of sodas is an important contributory factor to obesity, and is often associated with palatable food consumption. We studied the effects of 2-h intermittent access to sucrose-sweetened water (SSW, 12.3%, soda-like) and its schedule of administration on the response to chronic variable stress in mice fed a high-fat, high-sugar diet. C57BL/6 mice (n = 64) had access to water or to both water and 2-h SSW during 5 weeks, in addition to their diet. After the first two weeks, half of the animals from each group were stressed daily using a chronic variable stress (CVS) paradigm, while the other half were kept undisturbed. During the CVS exposure period, 2-h SSW access was either scheduled randomly, right before the stressors or right after the stressors. The effects of SSW and its schedule of administration on dietary intake, stress hormones and adiposity were analyzed. Results showed a larger consumption of SSW and higher bodyweight gain in mice receiving SSW after the stressor. In addition, SSW consumption was shown to affect appetite regulation by reducing CCK sensitivity. The present study suggests that SSW leads to overconsumption and weight gain only if provided after exposure to stress. These findings may implicate a relation between exposure to stress, binge-drinking behaviors of sugar sweetened beverages that ensues, and weight gain in humans consuming a western diet.

Background: We have reported large differences in adiposity (fat mass/body weight) gain between rats fed a low-fat, high-starch diet, leading to their classification into carbohydrate "sensitive" and "resistant" rats. In sensitive animals, fat accumulates in visceral adipose tissues, leading to the suggestion that this form of obesity could be responsible for rapid development of metabolic syndrome.Objective: We investigated whether increased amylase secretion by the pancreas and accelerated starch degradation in the intestine could be responsible for this phenotype.Method: Thirty-two male Wistar rats (7-wk-old) were fed a purified low-fat (10%), high-carbohydrate diet for 6 wk, in which most of the carbohydrate (64% by energy) was provided as corn starch. Meal tolerance tests of the Starch diet were performed to measure glucose and insulin responses to meal ingestion. Indirect calorimetry combined with use of C-13-labelled dietary starch was used to assess meal-induced changes in whole body and starch-derived glucose oxidation. Real-time polymerase chain reaction was used to assess mRNA expression in pancreas, liver, white and brown adipose tissues, and intestine. Amylase activity was measured in the duodenum, jejunum, and ileum contents. ANOVA and regression analyses were used for statistical comparisons.Results: "Resistant" and "sensitive" rats were separated according to adiposity gain during the study (1.73% +/- 0.20% compared with 4.35% +/- 0.36%). Breath recovery of (CO2)-C-13 from C-13-labelled dietary starch was higher in "sensitive" rats, indicating a larger increase in whole body glucose oxidation and, conversely, a larger decrease in lipid oxidation. Amylase mRNA expression in pancreas, and amylase activity in jejunum, were also higher in sensitive rats.Conclusion: Differences in digestion of starch can promote visceral fat accumulation in rats when fed a low-fat, high-starch diet. This mechanism may have important implications in human obesity.

External information can modify the subjective value of a tasted stimulus, but little is known about neural mechanisms underlying these behavioral modifications. This study used flavored drinks to produce variable degrees of discrepancy between expected and received flavor. During a learning session, 43 healthy young men learned 4 symbol-flavor associations. In a separate session, associations were presented again during an fMRI scan, but half of the trials introduced discrepancy with previously learned associations. Liking ratings of drinks were collected and were analyzed using a linear model to define the degree to which discrepant symbols affected liking ratings of the subjects during the fMRI session. Based on these results, a GLM analysis of fMRI data was conducted to determine neural correlates of observed behavior. Groups of subjects were composed based on their behavior in response to discrepant symbols, and comparison of brain activity between groups showed that activation in the PCC and the caudate nucleus was more potent in those subjects in which liking was not affected by discrepant symbols. These activations were not found in subjects who assimilated unexpected flavors to flavors preceeded by discrepant symbols. Instead, these subjects showed differences in the activity in the parietal operculum. The activity of reward network appears to be related to assimilation of received flavor to expected flavor in response to symbol-flavor discrepancy.

Background: Protein status is controlled by the brain, which modulates feeding behavior to prevent protein deficiency. Objective: This study tested in rats whether protein status modulates feeding behavior through brain reward pathways. Methods: Experiments were conducted in male Wistar rats (mean +/- SD weight; 230 +/- 16 g). In experiment 1, rats adapted for 2 wk to a low-protein (LP; 6% of energy) or a normal-protein (NP; 14% of energy) diet were offered a choice between 3 cups containing high-protein (HP; 50% of energy), NP, or LP feed; their intake was measured for 24 h. In 2 other experiments, the rats were adapted for 2 wk to NP and either HP or LP diets and received, after overnight feed deprivation, a calibrated HP, NP, or LP meal daily. After the meal, on the last day, rats were killed and body composition and blood protein, triglycerides, gut neuropeptides, and hormones were determined. In the brain, neuropeptide mRNAs in the hypothalamus and c-Fos protein and opioid and dopaminergic receptor mRNAs in the nucleus accumbens (NAcc) were measured. Results: Rats fed an LP compared with an NP diet had 7% lower body weight, significantly higher protein intake in a choice experiment (mean +/- SD: 30.5% +/- 0.05% compared with 20.5% +/- 0.05% of energy), higher feed-deprived blood ghrelin, lower postmeal blood leptin, and higher neuropeptide Y (Npy) and corticotropin-releasing hormone (Crh) mRNA expression in the hypothalamus. In contrast to NP, rats fed an LP diet showed postmeal c-Fos protein expression in the NAcc, which was significantly different between meals, with LP < NP < HP. In contrast, in rats adapted to an HP diet compared with an NP diet, energy intake was lower; and in the NAcc, meal-induced c-Fos protein expression was 20% lower, and mRNA expression was 17% higher for dopamine receptor 2 (Drd2) receptors and 38% lower for kappa opioid receptor (Oprk1) receptors. Conclusions: A protein-restricted diet induced a reward system-driven appetite for protein, whereas a protein-rich diet reduced the meal-induced activation of reward pathways and lowered energy intake in male rats.

Low protein (LP)-containing diets can induce overeating in rodents and possibly in humans in an effort to meet protein requirement, but the effects on energy expenditure (EE) are unclear. The present study evaluated the changes induced by reducing dietary protein from 20% to 6%-using either soy protein or casein-on energy intake, body composition, and EE in mice housed at 22°C or at 30°C (thermal neutrality). LP feeding increased energy intake and adiposity, more in soy-fed than in casein-fed mice, but also increased EE, thus limiting fat accumulation. The increase in EE was due mainly to an increase in spontaneous motor activity related to EE and not to thermoregulation. However, the high cost of thermoregulation at 22°C and the subsequent heat exchanges between nonshivering thermogenesis, motor activity, and feeding induced large differences in adaptation between mice housed at 22°C and at 30°C.

Nous avons révélé l’existence de rats sensibles à l’obésité sous régime standard riche en glucides et pauvres en graisses (Nadkarni et al., 2013). Ces rats sont appelés « carbohydrate sensitive » (CS) pour être démarqués des rats sensibles à l’obésité sous régime gras (rats dits « obesity prone » [OP]). Nous avons observé que les rats CS présentaient une augmentation des taux d’oxydation des glucides en réponse à un repas test (Chaumontet et al., 2015). L’objectif de notre étude a donc été de rechercher les mécanismes responsables de cette réponse. Les rats ont été soumis pendant 7 semaines à un régime riche en glucides complexes (amidon). Le poids et la prise alimentaire ont été mesurés 3 fois par semaine. La composition corporelle a été mesurée par IRM au début de l’introduction du régime (T0), puis après 3 (T3) et 6 (T6) semaines de régime. Le gain de masse grasse entre T0 et T3 nous a permis de sélectionner les rats sensibles (CS) et résistants (CR). Afin de mesurer l’oxydation postprandiale glucidique, les rats ont reçu un repas test de 56 kJ de même composition que leur régime, mais contenant soit de l’amidon (AMIDON) soit de la maltodextrine (MALTO) marqués au 13C. Les rats ont été placés en cage calorimétrique et leurs échanges respiratoires mesurés. L’enrichissement en 13CO2 dans les gaz expirés a été mesuré par multiflow-IRMS. À la fin de l’expérience, les animaux ont été euthanasiés, la composition corporelle mesurée par dissection des principaux tissus et le sang et les tissus cibles collectés pour les mesures biochimiques et d’expression de gênes. Comme nous l’avions préalablement observé, après trois semaines de régime, les rats CS sont significativement plus gras que les rats CR, mais le poids et la prise alimentaire ne diffèrent pas significativement. Suite à l’ingestion d’un repas MALTO, les taux postprandiaux d’oxydation des glucides et l’apparition de 13CO2 dans les gaz expirés augmentent rapidement mais de façon identique chez les rats CR et CS, ce qui indique que l’absorption et l’utilisation métabolique du glucose ne diffèrent pas entre les rats CS et CR. Par contre, suite à l’ingestion d’un repas AMIDON, les taux postprandiaux d’oxydation des glucides sont plus élevés chez les rats CS que chez les CR. Cette augmentation coïncide avec une apparition plus rapide du 13CO2 dans les gaz expirés qui indique que la digestion et l’utilisation métabolique des glucides alimentaires complexes sont plus rapides chez les rats CS. En outre, les ARNm codant l’amylase dans le pancréas sont augmentés chez les rats CS, de même que l’activité de l’amylase dans le jéjunum et dans le sang portal. L’augmentation de l’expression de l’amylase pancréatique chez les rats CS induit une accélération de la digestion et de l’utilisation métabolique du glucose dérivé des glucides complexes et est probablement responsable du développement progressif de obésité de type viscéral (Nadkarni et al., 2013) observée chez les rats « carbohydrate-sensitive ».

The degree to which consumers expect foods to satisfy hunger, referred to as expected satiation, has been reported to predict food intake. Yet this relationship has not been established precisely, at a quantitative level. We sought to explore this relationship in detail by determining whether expected satiation predicts the actual intake of semi-solid desserts. Two separate experiments were performed: the first used variations of a given food (eight apple purées), while the second involved a panel of different foods within a given category (eight desserts). Both experiments studied the consumption of two products assigned to volunteers based on their individual liking and expected satiation ratings, given ad libitum at the end of a standardised meal. A linear model was used to find predictors of food intake and included expected satiation scores, palatability scores, BMI, age, sex, TFEQ-R, TFEQ-D, water consumption during the meal, reported frequency of eating desserts, and reported frequency of consuming tested products as explanatory variables. Expected satiation was a significant predictor of actual food intake in both experiments (apple purée: F(1,97) = 18.60, P < .001; desserts: F(1,106) = 9.05, P < .01), along with other parameters such as product palatability and the volunteers' age, sex and food restriction (variation explained by the model/expected satiation in the experiments: 57%/23% and 36%/17%, respectively). However, we found a significant gap between expected and actual consumption of desserts, on group and on individual level. Our results confirm the importance of expected satiation as a predictor of subsequent food intake, but highlight the need to study individual consumption behaviour and preferences in order to fully understand the role of expected satiation.

Human consumption of obesogenic diets and soft drinks, sweetened with different molecules, is increasing worldwide, and increases the risk of metabolic diseases. We hypothesized that the chronic consumption of caloric (sucrose, high-fructose corn syrup (HFCS), maltodextrin) and non-caloric (sucralose) solutions under 2-hour intermittent access, alongside the consumption of a high-fat high-sucrose diet, would result in differential obesity-associated metabolic abnormalities in mice. Male C57BL/6 mice had ad libitum access to an HFHS diet and to water (water control group). In addition, some mice had access, 2h/day, 5days/week (randomly chosen) for 12weeks, to different solutions: i) a sucrose solution (2.1kJ/ml), ii) an HFCS solution (2.1kJ/ml), iii) a maltodextrin solution (2.1kJ/ml) and a sucralose solution (60mM) (n=15/group). Despite no changes in total caloric intake, 2h-intermittent access to the sucrose, HFCS or maltodextrin solutions led to increased body weight and accumulation of lipids in the liver when compared to the group consuming water only. The HFCS and sucrose solutions induced a higher fat mass in various fat depots, glucose intolerance, increased glucose oxidation at the expense of lipid oxidation, and a lower hypothalamic expression of NPY in the fasted state. HFCS also reduced proopiomelanocortin expression in the hypothalamus. 2h-intermittent access to sucralose did not result in significant changes in body composition, but caused a stronger expression of CART in the hypothalamus. Finally, sucrose intake showed a trend to increase the expression of various receptors in the nucleus accumbens, linked to dopamine, opioid and endocannabinoid signaling. In conclusion, 2h-intermittent access to caloric solutions (especially those sweetened with sucrose and HFCS), but not sucralose, resulted in adverse metabolic consequences in high-fat high-sucrose-fed mice.

The ingestion of low or high lipid diets enriched with fructo-oligosaccharide (FOS) affects energy homeostasis. Ingesting protein diets also induces a depression of energy intake and decreases body weight. The goal of this study was to investigate the ability of FOS, combined or not with a high level of protein (P), to affect energy intake and body composition when included in diets containing different levels of lipids (L). We performed two studies of similar design over a period of 5 weeks. During the first experiment (exp1), after a 3-week period of adaptation to a normal protein-low fat diet, the rats received one of the following four diets for 5 weeks (6 rats per group): (i) normal protein (14% P/E (Energy) low fat (10% L/E) diet, (ii) normal protein, low fat diet supplemented with 10% FOS, (iii) high protein (55%P/E) low fat diet, and (iv) high protein, low fat diet supplemented with 10% FOS. In a second experiment (exp2) after the 3-week period of adaptation to a normal protein-high fat diet, the rats received one of the following 4 diets for 5 weeks (6 rats per group): (i) normal protein, high fat diet (35% of fat), (ii) normal protein, high fat diet supplemented with 10% FOS, (iii) high protein high fat diet and (iv) high protein high fat diet supplemented with 10% FOS. In low-fat fed rats, FOS did not affect lean body mass (LBM) and fat mass but the protein level reduced fat mass and tended to reduce adiposity. In high-fat fed rats, FOS did not affect LBM but reduced fat mass and adiposity. No additive or antagonistic effects between FOS and the protein level were observed. FOS reduced energy intake in low-fat fed rats, did not affect energy intake in normal-protein high-fat fed rats but surprisingly, and significantly, increased energy intake in high-protein high-fat fed rats. The results thus showed that FOS added to a high-fat diet reduced body fat and body adiposity.

SCOPE:Food structure is a key factor controlling digestion and nutrient absorption. We test the hypothesis that protein emulsion structure in the diet may affect digestive and absorptive processes.METHODS & RESULTS:Rats (n = 40) are fed for 3 weeks with two diets chemically identical but based on lipid-protein liquid-fine (LFE) or gelled-coarse (GCE) emulsions that differ at the macro- and microstructure levels. After an overnight fasting, they ingest a 15 N-labeled LFE or GCE test meal and are euthanized 0, 15 min, 1 h, and 5 h later. 15 N enrichment in intestinal contents and blood are measured. Gastric emptying, protein digestion kinetics, 15 N absorption, and incorporation in blood protein and urea are faster with LFE than GCE. At 15 min time point, LFE group shows higher increase in GIP portal levels than GCE. Three weeks of dietary adaptation leads to higher expression of cationic amino acid transporters in ileum of LFE compared to GCE. LFE diet raises cecal butyrate and isovalerate proportion relative to GCE, suggesting increased protein fermentation. LFE diet increases fecal Parabacteroides relative abundance but decreases Bifidobacterium, Sutterella, Parasutterella genera, and Clostridium cluster XIV abundance.CONCLUSION:Protein emulsion structure regulates digestion kinetics and gastrointestinal physiology, and could be targeted to improve food health value.

EDITORIAL article Front. Nutr., 01 December 2017Sec. Clinical Nutrition Volume 4 - 2017 | https://doi.org/10.3389/fnut.2017.00058

SCOPE:Few studies have evaluated in vivo the impact of food structure on digestion, absorption of nutrients and on microbiota composition and metabolism. In this study we evaluated in rat the impact of two structures of protein emulsion in food on gut microbiota, luminal content composition, and intestinal characteristics. METHODS AND RESULTS:Rats received for 3 weeks two diets of identical composition but based on lipid-protein matrices of liquid fine (LFE) or gelled coarse (GCE) emulsion. LFE diet led to higher abundance, when compared to the GCE, of Lactobacillaceae (Lactobacillus reuteri) in the ileum, higher β-diversity of the caecum mucus-associated bacteria. In contrast, the LFE diet led to a decrease in Akkermansia municiphila in the caecum. This coincided with heavier caecum content and higher amount of isovalerate in the LFE group. LFE diet induced an increased expression of (i) amino acid transporters in the ileum (ii) glucagon in the caecum, together with an elevated level of GLP-1 in portal plasma. However, these intestinal effects were not associated with modification of food intake or body weight gain. CONCLUSION:Overall, the structure of protein emulsion in food affects the expression of amino acid transporters and gut peptides concomitantly with modification of the gut microbiota composition and activity. Our data suggest that these effects of the emulsion structure are the result of a modification of protein digestion properties.

IntroductionProtein together with energy is an essential component of the diet. Implicit control of protein consumption is a key element of food decision‐making and behavior in humans. However, it is unclear which food characteristics, especially sensory, are the determinants of food choices guiding to adequate protein intake. A low‐protein diet is known to induce unconscious search for foods containing protein. By comparing food preferences of human subjects under a low‐protein diet to preferences of the same subjects subjected to a balanced diet, this study aimed at identifying implicit determinants of protein level in common foods.Materials and Methods23 healthy volunteers (13 women) 18 to 35 years old, non‐overweight (BMI between 18 and 25 kg/m2) followed two successive dietary interventions in a randomized crossover design during which they consumed either a diet containing 0.5g of protein/kg body weight/day, or 1.4g protein/kg/day. Both diets were iso‐energetic and variations in protein content were compensated by variations in both carbohydrates and fats. Experimental diets lasted 4 days each and were separated by a 10‐day wash‐out period during which participants were instructed to go back to their normal diet. At the beginning and at the end of each experimental diet period participants completed an on‐screen task during which they choose the preferred food from two food photographs. Foods present on photographs differed in protein content, portion size, or sensory qualities. A total of 153 pairs was used. Based on this task, preference scores for each food was estimated using the Bradley‐Terry method for analysis of paired comparisons. Effect of subjects' protein status on preference scores and its interaction with food sensory and nutritional characteristics was then evaluated.ResultsPreference analysis showed a significant effect of subjects' protein status on food preference scores (p=0.0047). A significant interaction was found between protein status and portion size (p=0.0002), a low‐protein diet resulting in a preference for larger portions. Other food characteristics such as protein content of foods and their sweet or salty taste, did not appear to affect preferences in a situation of low protein status (p=0.11 and p=0.14, respectively).ConclusionThis study showed an alteration of food preferences induced by a low‐protein diet, observed after 4‐day dietary intervention. Subjects following a low‐protein diet appear to prefer larger food portions that could be interpreted as an attempt to restore protein balance.Support or Funding InformationThe study was funded by a grant from French Nutrition Society

Le contrôle de la consommation de protéines, qui représentent une composante du régime strictement indispensable à la survie, est un élément clé dans les processus de contrôle de choix et de l’ingestion alimentaire chez l’humain. On ignore cependant les critères décisionnels, sensoriels notamment, sur lesquels nous basons nos choix alimentaires en vue d’assurer l’adéquation de notre régime à nos besoins protéiques. Un régime déficient en protéines est connu pour entraîner une recherche non consciente de protéines alimentaires. En comparant les choix d’une cohorte de sujets en déficience protéique à ceux des même sujets consommant les protéines à un niveau habituel, nous avons cherché à identifier les critères implicites d’évaluation de la teneur en protéine des aliments. Vingt-trois sujets sains (dont 13 femmes) ont été recrutés, âgés entre 18 et 35 ans, l’IMC compris entre 18 et 25 kg/m2 et ne suivant pas de régime particulier. Ces sujets ont suivi deux phases d’intervention successives, durant lesquelles ils ont consommé des régimes apportant soit 0,5 g de protéine/kg/j, soit 1,4 g/kg/j. Les deux régimes étaient isoénergétiques et la variation de la teneur en protéines était compensée par une variation de la teneur en lipides et en glucides. Chaque période de régime a duré 4j, les périodes étant séparées par 10 j où les sujets ont retrouvé leur alimentation habituelle. À la fin de chaque période de régime, les sujets ont complété un test lors duquel il leur a été demandé de choisir l’aliment préféré parmi des paires d’images d’aliments différant par leur teneur en protéines, taille de portion, ou qualités sensorielles (total de 153 comparaisons). Le score de préférence a été estimé pour les différents aliments évalués à l’aide des modèles de Bradley-Terry. L’effet du régime sur ces scores de préférence, ainsi que son interaction avec les qualités nutritionnelles et sensorielles des aliments, a été ensuite étudié. L’analyse des tests de préférence a révélé un effet significatif du régime sur les préférences alimentaires des sujets (p = 0,0047). En particulier, le facteur régime a montré une interaction significative avec le facteur taille de portion (p = 0,0002) : en effet, le poids accordé au facteur taille de portion était significativement plus important pour les préférences observées après régime à teneur en protéines plus basse. Les autres facteurs relatifs aux qualités des aliments, à savoir, la teneur en protéines des aliments et leur goût salé ou sucré, n’ont pas manifesté d’interaction avec le facteur régime (p = 0,11 et p = 0,14, respectivement). Cette étude a permis de mettre en évidence des modifications de préférences induites par une diminution de consommation protéique, et ce dès 4 j de régime réduit en protéines. Les sujets soumis à une restriction protéique semblent orienter leurs choix vers des tailles de portion plus importantes. Tandis qu’une telle stratégie pourrait effectivement augmenter les apports protéiques, elle pose des problèmes potentiels de dépassement de consommation calorique. Il convient de s’interroger sur les mécanismes causant ces choix, afin d’étudier la possibilité d’orienter les consommateurs vers des aliments plus riches en protéines par exemple.

Background: Cooking may impair meat protein digestibility. When undigested proteins are fermented by the colon microbiota, they can generate compounds that potentially are harmful to the mucosa. Objectives: This study addressed the effects of typical cooking processes and the amount of bovine meat intake on the quantity of undigested proteins entering the colon, as well as their effects on the intestinal mucosa. Methods: Male Wistar rats (n = 88) aged 8 wk were fed 11 different diets containing protein as 20% of energy. In 10 diets, bovine meat proteins represented 5% [low-meat diet (LMD)] or 15% [high-meat diet (HMD)] of energy, with the rest as total milk proteins. Meat was raw or cooked according to 4 processes (boiled, barbecued, grilled, or roasted). A meat-free diet contained only milk proteins. After 3 wk, rats ingested a 15N-labeled meat meal and were killed 6 h later after receiving a 13C-valine injection. Meat protein digestibility was determined from 15N enrichments in intestinal contents. Cecal short- and branched-chain fatty acids and hydrogen sulfide were measured. Intestinal tissues were used for the assessment of protein synthesis rates, inflammation, and histopathology. Results: Meat protein digestibility was lower in rats fed boiled meat (94.5% ± 0.281%) than in the other 4 groups (97.5% ± 0.0581%, P < 0.001). Cecal and colonic bacterial metabolites, inflammation indicators, and protein synthesis rates were not affected by cooking processes. The meat protein amount had a significant effect on cecal protein synthesis rates (LMD > HMD) and on myeloperoxidase activity in the proximal colon (HMD > LMD), but not on other outcomes. The ingestion of bovine meat, whatever the cooking process and the intake amount, resulted in discrete histologic modifications of the colon (epithelium abrasion, excessive mucus secretion, and inflammation). Conclusions: Boiling bovine meat at a high temperature (100°C) for a long time (3 h) moderately lowered protein digestibility compared with raw meat and other cooking processes, but did not affect cecal bacterial metabolites related to protein fermentation. The daily ingestion of raw or cooked bovine meat had no marked effect on intestinal tissues, despite some slight histologic modifications on distal colon.

We tested the hypothesis that, for rats fed a high-fat diet (HFD), a prioritization of maintaining protein intake may increase energy consumption and hence result in obesity, particularly for individuals prone to obesity (“fat sensitive,” FS, vs. “fat resistant,” FR). Male Wistar rats ( n = 80) first received 3 wk of HFD (protein 15%, fat 42%, carbohydrate 42%), under which they were characterized as being FS ( n = 18) or FR ( n = 20) based on body weight gain. They then continued on the same HFD but in which protein (100%) was available separately from the carbohydrate:fat (50:50%) mixture. Under this second regimen, all rats maintained their previous protein intake, whereas intake of fat and carbohydrate was reduced by 50%. This increased protein intake to 26% and decreased fat intake to 37%. Adiposity gain was prevented in both FR and FS rats, and gain in fat-free mass was increased only in FS rats. At the end of the study, the rats were killed 2 h after ingestion of a protein meal, and their tissues and organs were collected for analysis of body composition and measurement of mRNA levels in the liver, adipose tissue, arcuate nucleus, and nucleus accumbens. FS rats had a higher expression of genes encoding enzymes involved in lipogenesis in the liver and white adipose tissue. These results show that FS rats strongly reduced food intake and adiposity gain through macronutrient selection, despite maintenance of a relatively high-fat intake and overexpression of genes favoring lipogenesis.