Individual amino acid balances in young lean and obese Zucker rats fed a cafeteria diet

The amino acid composition of the diet ingested by reference and cafeteria diet-fed lean and obese Zucker rats has been analyzed from day 30 to 60 after birth. Their body protein amino acid composition was measured, as well as the urinary and faecal losses incurred during the period studied. The protein actually selected by the rats fed the cafeteria diet had essentially the same amino acid composition as the reference diet. The mean protein amino acid composition of the rat showed only small changes with breed, age or diet.Cafeteria-fed rats had a higher dietary protein digestion/absorption efficiency than reference diet-fed rats. Obese rats wasted a high proportion of dietary amino acids when given the reference diet, but not on the cafeteria diet. In all cases, the amino acids lost as such in the urine were a minimal portion of available amino acids.In addition to breed, the rates of protein accretion are deeply influenced by diet, but even more by the age — or size — of the animals: cafeteria-fed rats grew faster, to higher body protein settings, but later protein accrual decreased considerably; this is probably due to a limitation in the blueprint for growth which restricts net protein deposition when a certain body size is attained. Obese rats, however, kept accuring protein with high rates throughout.Diet composition — and not protein availability or quality-induced deep changes in amino acid metabolism. Since the differences in the absolute levels of dietary protein or carbohydrate energy ingested by rats fed the reference or cafeteria diets were small, it can be assumed that high (lipid) energy elicits the changes observed in amino acid metabolism by the cafeteria diet. The effects induced in the fate of the nitrogen ingested were more related to the fractional protein energy proportion than to its absolute values. Cafeteria-fed rats tended to absorb more amino acids and preserve them more efficiently; these effects were shown even under conditions of genetic obesity.There were deep differences in handling of dietary amino acids by dietary or genetically obese rats. The former manage to extract and accrue larger proportions of their dietary amino acids than the latter. The effects of both models of amino acid management were largely additive, suggesting that the mechanisms underlying the development of obesity did not run in parallel to those affecting the control of amino acid utilization. Obesity may be developed in both cases despite a completely different strategy of amino acid assimilation, accrual and utilization. (Mol Cell Biochem121: 45–58, 1993)     

Plasma amino acids of lean and obese Zucker rats subjected to a cafeteria diet after weaning.

Plasma amino acids of Zucker obese (fa/fa) and lean (Fa/?) rats fed either a reference nonpurified pellet or a cafeteria diet have been studied from 30 to 60 days after birth. Obese rats showed higher plasma branched chain amino acid levels but similar total amino acids, urea and glucose concentrations. The ingestion of a cafeteria diet induced higher levels in many amino acids, as well as in the composite figure in lean rats, but failed to alter total 2-amino nitrogen concentrations in obese rats, despite high levels in several non-essential amino acids and lower values in essential amino acids; urea levels were much lower in rats fed the cafeteria diet. The results are consistent with an impairment of amino acid nitrogen elimination via urea cycle in cafeteria diet-fed rats. This is independent of the hyperinsulinemia-driven plasma accumulation of several essential amino acids induced by genetic obesity. The effects were, then additive.     

Modulatory role of food, feeding regime and physical exercise on body weight and insulin resistance

Energy intake and expenditure is a highly conserved and well-controlled system with a bias toward energy intake. In times of abundant food supply, individuals tend to overeat and in consequence to increase body weight, sometimes to the point of clinical obesity. Obesity is a disease that is not only characterized by enormous body weight but also by rising morbidity for diabetes type II and cardiovascular complications. To better understand the critical factors contributing to obesity we performed the present study in which the effects of energy expenditure and energy intake were examined with respect to body weight, localization of fat and insulin resistance in normal Wistar rats. It was found that a diet rich in fat and carbohydrates similar to "fast food" (cafeteria diet) has pronounced implication in the development of obesity, leading to significant body weight gain, fat deposition and also insulin resistance. Furthermore, an irregularly presented cafeteria diet (yoyo diet) has similar effects on body weight and fat deposition. However, these rats were not resistant to insulin, but showed an increased insulin secretion in response to glucose. When rats were fed with a specified high fat/carbohydrate diet (10% fat, 56.7% carbohydrate) ad lib or at the beginning of their activity phase they were able to detect the energy content of the food and compensate this by a lower intake. They, however, failed to compensate when food was given in the resting phase and gained more body weight as controls. Exercise, even of short duration, was able to keep rats on lower body weight and reduced fat deposition. Thus, inappropriate food intake with different levels of energy content is able to induce obesity in normal rats with additional metabolic changes that can be also observed in humans.     

Spontaneous and experimental variations in body weight, food intake and metabolic rate in captive dormice (Glis glis)

Captive dormice (Glis glis) showed spontaneous cyclical fluctuations in body weight that were not synchronous between animals and not directly related to season. Presenting the animals with a varied and palatable (cafeteria) diet for short periods caused marked increases in energy intake and body weight, and higher levels of oxygen consumption (V02). The level of hyperphagia was fairly constant, but the rise in V02 during cafeteria feeding varied (20-80%) according to season, being greatest in the winter (Nov.-Jan.). Removal of the cafeteria foods caused weight loss, hypophagia and a fall in V02 to levels below that seen in either normally-fed or fasted dormice. This hypometabolism was associated with increased periods of sleep and torpor, and it is suggested that the excess fat deposition resulting from cafeteria feeding may have induced a transient "hibernation-like" state.     

Fatty acid utilization by young Wistar rats fed a cafeteria diet

The content and accretion of fatty acids in 30, 45 and 60-day old Wistar rats fed either reference chow or a cafeteria diet has been studied, together with their actual fatty acid intake during that period. Diet had a small overall effect on the pattern of deposition of fatty acids, but the deposition of fat was much higher in cafeteria rats. The fat-rich cafeteria diet allowed the direct incorporation of most fatty acids into lipid storage, whilst chow-feeding activated lipogenesis and the deposition of a shorter chain and more saturated type of fatty acids. During the second month of the rat's life, the elongation pathway as well as ⁹-desaturase became functional, thus helping to shape the pattern of fatty acids actually accrued. The 60-day rats showed a relative impairment in the operation of ⁵-desaturase, since their lipids had a higher C20:4/C20:3 ratio than those of the diet ingested. Cafeteria-diet feeding minimized this effect since the large supply of dietary polyunsaturated fatty acids made the operation of the elongation-desaturase pathways practically unnecessary.     

Systemic lupus erythematosus onset in lupus-prone B6.MRL/lpr mice Is influenced by weight gain and Is preceded by an increase in neutrophil oxidative burst activity

In this study, we assessed whether weight gain influenced the systemic lupus erythematosus (SLE) onset and/or outcome, and examined the role that reactive oxygen species (ROS) production by neutrophils played in the SLE onset and/or outcome. Female control (C57BL/6) and lupus-prone B6.MRL/lpr mice (CM and LPM, respectively) at 4 weeks old were fed standard diet or standard diet plus cafeteria diet during 12 weeks. SLE diagnosis relied on the presence of both antinuclear antibodies (ANA) and renal abnormalities. We found that the percentage of weight gain in CM and LPM increased as a function of the length of cafeteria diet feeding period, but it was not associated with energy intake. Cafeteria diet-fed CM and LPM at 8 and 12 weeks old were overweight, while CM and LPM at 16 weeks old were obese. Compared with standard diet-fed CM and LPM, cafeteria diet-fed CM and LPM exhibited elevated glucose and total cholesterol levels, and diminished triglycerides levels. Standard diet-fed 16-week-old LPM and cafeteria diet-fed 12-week-old LPM had nephritis, characterized by the increased interstitial infiltration of leukocytes. Cafeteria diet-induced weight gain rose the frequency of homogeneous and speckled ANA staining patterns in the 12- and 16-week-old LPM groups. Together, these results indicated that weight gain anticipated the SLE onset. In addition, neutrophils from cafeteria diet-fed 8-week-old LPM exhibited augmented ROS production capacity; in standard diet-fed LPM, such rise occurred only in the 16-week-old group. Thus, the neutrophil ROS production capacity was increased before the SLE onset and during its outcome. Overweight and obese CM and LPM displayed elevated levels of kidney, liver, heart, and spleen lipid peroxidation. In conclusion, cafeteria diet-induced weight gain is associated with the increased production of ANA and neutrophil-derived ROS, which may contribute to accelerate the SLE onset.     

Ketoconazole, an antifungal agent, protects against adiposity induced by a cafeteria diet.

Ketoconazole, an anti-glucocorticoid agent, is widely used in humans as an antifungal agent. It inhibits ergosterol synthesis and reduces cortisol levels in the treatment of Cushing's Syndrome. The aim of this work was to study the drug's preventive potential against adiposity induced by a high-fat cafeteria diet in rats. Female Wistar rats were fed on standard pelleted diet or cafeteria diet during 42 days in the presence or absence of an oral treatment with ketoconazole (24 mg/kg of body weight). The cafeteria diet increased energy intake and body weight. In addition, this high-fat diet increased body-fat weight and adipose tissue depots analyzed. Interestingly, ketoconazole was able to protect against increased total body fat and adipose depot enlargement induced after cafeteria-diet feeding. Moreover, ex vivo isoproterenol-induced lipolysis was reduced in adipocytes from cafeteria-fed animals; this decrease was reverted by treatment with ketoconazole. Thus, ketoconazole was able to protect against adiposity induced by a cafeteria diet, revealing an interaction between fat intake and glucocorticoids on adipose deposition.     

Effects of chronic heat exposure and protein intake on growth performance, nitrogen retention and muscle development in broiler chickens

The respective effects of ambient temperature, dietary crude protein and feed intake were investigated in finishing chickens and the consequence of protein supplementation under high temperature conditions was analysed in particular. Heat-related reduction in growth was associated with decreased nitrogen retention (-30 or -35% according to the diet), which could not be explained by the observed lower feed intake alone. Tissue samples performed in 5- to 6-week-old chicks showed varying effects of heat according to the muscles studied: at 32 degrees C, the proportion of Pectoralis major muscle (in percentage of body weight) appeared slightly reduced (reduction lower than 10%), whereas the proportion of two leg muscles were increased (+10 to +15% for the Sartorius muscle; +5% for the gastrocnemius muscle). At 32 degrees C, providing a high protein diet significantly (P < 0.05) increased weight gain and feed efficiency, and slightly improved whole body protein deposition.     

Adjustments to nitrogen metabolism during wing moult in Greylag Geese, Anser anser

1. This study examined the nitrogen balance of free-living flightless moulting Greylag Geese, Anser anser , in relation to food quality, nitrogen absorption, food retention time and nitrogen excretion rates.
2. Food intake rates during moult were the same as those before and after the flightless period, but total daily time spent foraging fell by 58% from 9·45 h to 3·96 h. Dropping production during moult was 43%, and mean dropping mass 42% of that before and after moult, suggesting a considerable increase in food passage time through the gut during moult. Nitrogen absorption increased from 25% prior to moult to 47% during moult.
3. At the same time, excreted dry mass uric acid in faecal material fell by 68%, such that the proportion of nitrogen absorbed and retained in the body as a proportion of the nitrogen ingested in food rose from 16% prior to moult to 42% during moult.
4. Based on these significant increases in nitrogen absorption and decreases in nitrogen excretion, geese were able to compensate for reduced food intake and derive sufficient nitrogen from their diet to re-grow flight feathers.     

Ammonia excretion increased and urea excretion decreased in urine of a new world nectarivorous bat with decreased nitrogen intake

We determined the effect of water and nitrogen intake on nitrogenous waste composition in the nectarivorous Pallas's long-tongued bat Glossophaga soricina (Phyllostomidae) to test the hypothesis that bats reduce excretion of urea nitrogen and increase the excretion of ammonia nitrogen as nitrogen intake decreases and water intake decreases. Because changes in urine nitrogen composition are expected only in animals whose natural diets are low in nitrogen and high in water content, we also measured maintenance nitrogen requirements (MNR). We hypothesized that, similar to other plant-eating vertebrates, nectarivorous bats have low MNR. Our nitrogen excretion hypothesis was partly proved correct. There was an increase in the proportion of N excreted as ammonia and a decrease in the proportion excreted as urea in low-nitrogen diets. The proportion of N excreted as ammonia and urea was independent of water intake. Most individuals were ureotelic (n = 28), and only a few were ureo-ammonotelic (n = 3) or ammonotelic (n = 2). According to our nitrogen requirement hypothesis, apparent MNR (60 mg kg(-0.75) d(-1)) and truly digestible MNR (54 mg N kg(-0.75) d(-1)) were low. A decrease in urea excretion in low-nitrogen diets may result from urea recycling from liver to the gut functioning as a nitrogen salvage system in nectarivorous bats. This mechanism probably contributes to the low MNR found in Pallas's long-tongued bats.     

Individual severity of dietary obesity in unselected Wistar rats: relationship with hyperphagia

We investigated the relative importance of overeating, thermogenesis, and uncoupling protein (UCP) expression in determining the severity of obesity in male Wistar rats fed a highly palatable diet. After 2 wk of feeding, body weight did not differ significantly from controls (248 +/- 4 vs. 229 +/- 3 g; P > 0.3), but rectal temperature, brown adipose tissue (BAT) mass, UCP3 expression in gastrocnemius muscle, and UCP2 expression in white adipose tissue (WAT) were all elevated in diet-fed animals. In a further study, rats fed a palatable diet for 8 wk exhibited higher energy intake and rectal temperature than controls. Dietary-obese rats were divided into high (427-490 g; n = 8) and low (313-410 g; n = 10) weight gainers. The high gainers ate significantly more than the low gainers, and energy intake was positively correlated with weight gain (r(2) = 0.72, P < 0.01). UCP2 and UCP3 mRNA levels in gastrocnemius muscle were significantly increased above lean controls in all diet-fed animals, whereas UCPs in WAT and BAT did not differ significantly from controls. Whereas rats fed palatable food exhibited a thermogenic response, there was no significant difference in core temperature between high and low gain groups (37. 5 +/- 0.1 vs. 37.6 +/- 0.1 degrees C; P > 0.5). We conclude that a higher energy intake is the critical factor determining susceptibility to dietary obesity in unselected Wistar rats.     

Anti-obese activity of Butea monosperma (Lam) bark extract in experimentally induced obese rats

To study the efficacy of ethanolic extract of B. monosperma bark in cafeteria and atherogenic diet fed rats and monosodium glutamate (MSG) obese rats, different doses (200, 400 and 800 mg/kg) of ethanolic extract of B. monosperma bark showed dose dependent decrease in body weight, daily food intake, glucose, lipids, internal organs' weight and fat pad weight in cafeteria and atherogenic diet fed rats and monosodium glutamate obese rats. The results suggested that B. monosperma has significant anti-obese activity.     

Fatty acid synthesis and generation of glycerol-3-phosphate in brown adipose tissue from rats fed a cafeteria diet

In vivo fatty acid synthesis and the pathways of glycerol-3-phosphate (G3P) production were investigated in brown adipose tissue (BAT) from rats fed a cafeteria diet for 3 weeks. In spite of BAT activation, the diet promoted an increase in the carcass fatty acid content. Plasma insulin levels were markedly increased in cafeteria diet-fed rats. Two insulin-sensitive processes, in vivo fatty acid synthesis and in vivo glucose uptake (which was used to evaluate G3P generation via glycolysis) were increased in BAT from rats fed the cafeteria diet. Direct glycerol phosphorylation, evaluated by glycerokinase (GyK) activity and incorporation of [U-14C]glycerol into triacylglycerol (TAG)-glycerol, was also markedly increased in BAT from these rats. In contrast, the cafeteria diet induced a marked reduction of BAT glyceroneogenesis, evaluated by phosphoenolpyruvate carboxykinase-C activity and incorporation of [1-14C]pyruvate into TAG-glycerol. BAT denervation resulted in an approximately 50% reduction of GyK activity, but did not significantly affect BAT in vivo fatty acid synthesis, in vivo glucose uptake, or glyceroneogenesis. The data suggest that the supply of G3P for BAT TAG synthesis can be adjusted independently from the sympathetic nervous system and solely by reciprocal changes in the generation of G3P via glycolysis and via glyceroneogenesis, with no participation of direct phosphorylation of glycerol by GyK.     

建鲤和异育银鲫摄食不同质量饲料时的氮收支和能量收支比较

实验探讨了建鲤和异育银鲫摄食低质和高质饲料时氮和能量的收支情况.低质饲料以豆粕为主要蛋白源,饲料蛋白含量为33.91%,高质饲料以鱼粉为主要蛋白源,饲料蛋白含量为45.59%.55d的生长结果显示,氮收支和能量收支受到饲料质量和鱼类种类的显著影响:摄食低质饲料时,建鲤的生长氮和生长能比例显著低于异育银鲫,排泄氮、排泄能和代谢能比例显著高于异育银鲫;摄食高质饲料时,两种鱼的氮收支和能量收支无显著差异;建鲤的氮收支和能量收支受饲料质量的显著影响,摄食低质饲料时,其生长氮和生长能比例均显著低于摄食高质饲料时,而排泄氮、粪能和代谢能比例均显著高于摄食高质饲料时;异育银鲫的氮收支、生长能和代谢能比例不受饲料质量的显著影响.结果表明,在低质饲料条件下,建鲤利用氮和能量的能力弱于异育银鲫,在高质饲料条件下,两种鱼没有显著差异.与异育银鲫相比,建鲤利用氮和能量的能力受饲料质量的影响更为显著.       

Manipulation of dietary methionine+cysteine and threonine in broilers significantly decreases environmental nitrogen excretion

The intensification of livestock have increased the emission of pollutants to the environment, leading to a growing interest in seeking strategies that minimise these emissions. Studies have shown that it is possible to manipulate diets by reducing CP levels and thus reducing nitrogen (N) excretion, without compromising performance. However, there is no knowledge of any study that has focused on reducing N excretion and relating this reduction to individual amino acids. This study investigated the effect of dietary methionine+cysteine (MC) and threonine (THR), the two most limiting amino acids for broiler production, on nitrogen excretion (NE) and nitrogen deposition (ND) and determined the efficiency of utilisation of both amino acids for protein deposition. Six trials were conducted to measure the NE and ND in broiler chickens during three rearing phases in response to dietary amino acid. The efficiency of utilisation of the amino acids was calculated by linear regression of body protein deposition and the amino acid intake. Despite the differences between sexes and phases, the efficiency of utilisation was the same, being 0.60 and 0.59 for MC and THR, respectively. The rate of NE behaved exponentially, increasing with amino acid intake, and can exceed 50% of N intake, being higher than ND. On average, for a reduction in intake of each unit of MC or THR (mg) there is a reduction of 0.5% of NE. Although this reduction seems low, considering that it corresponds to changes in one amino acid only, the impact on a large scale would be significant. Knowledge of how animals respond to NE and ND/protein deposition according to amino acid dietary content may represent new efforts towards reducing the impact on environment.     

Effects of adrenalectomy on energy balance, diet-induced thermogenesis and brown adipose tissue in adult cafeteria-fed rats

Feeding adult male rats a palatable cafeteria diet stimulated energy intake and expenditure but also raised body weight and energy gains. Bilateral adrenalectomy (ADX) had little effect on stock-fed animals, but prevented the development of obesity in cafeteria-fed rats by depressing food intake and energetic efficiency. Adrenalectomy also markedly increased the thermogenic activity of brown adipose tissue, and depressed insulin levels, particularly in the cafeteria group.     

Effect of vitamin A content in cafeteria diet on the expression of nuclear receptors in rat subcutaneous adipose tissue

The aim of this study was to determine the effects of cafeteria diet containing control or elevated level of vitamin A on the expression of nuclear receptors in adipose tissue. Male Wistar rats were submitted to 3 experimental diets during 8 weeks, a standard diet and two hyper-energetic, hyperlipidic "cafeteria" diets containing normal (Caf) or higher (Caf+) vitamin A level. During the experiment, body weights and energy intakes were measured. At the end of the experimental period, subcutaneous adipose tissue (Swat) and all the fat mass were removed and weighted. Nuclear receptors mRNA levels of RARalpha, RARgamma, RXRalpha, PPARgamma were measured in the Swat by a real-time semi-quantitative RT-PCR method. We observed that energy intake of Caf+ and Caf groups was significantly higher than that of the control group. Despite a higher increase of the energy intake in the Caf group compared to the Caf+ group, no significant difference was observed in the body weight gain of the Caf+ compared to the Caf group. The Caf+ and Caf diets led to a significant increase of adipose tissue in cafeteria groups as observed in the Swat depot. The mRNA levels of PPARgamma and RXRalpha were significantly increased in the Caf+ group as compared to control group, with a significant positive correlation between these two parameters. Expressions of RARalpha and RARgamma were not modified in experimental groups compared to controls. In conclusion, 8-week exposure to cafeteria diets with normal and higher levels of vitamin A led to an increase of adiposity in rats, associated, only in the group fed with the higher vitamin A level cafeteria diet, with an increase of PPARgamma and RXRalpha expressions in subcutaneous adipose tissue.     

Positive correlation of skeletal muscle UCP3 mRNA levels with overweight in male,but not in female,rats

The objective of this study was to investigate the sex-dependent regulation of skeletal muscle uncoupling protein (UCP)3 mRNA expression in response to overweight and its relationship with serum levels of free fatty acids, leptin, and insulin. Two obesity models were used: rats made obese by feeding them with a cafeteria diet for 14 wk, and postcafeteria overweight rats fed a chow diet for 10 wk after consuming the cafeteria diet for 14 wk. The effects of 24-h fasting were studied in postcafeteria rats and their age-matched controls. The cafeteria rats ate a high-fat diet and attained an excess body weight that was higher in females (+59%) than in males (+39%). A trend to higher induction of abdominal muscle UCP3 mRNA in male rats than in females after cafeteria diet was apparent (+116% increase vs. +26% increase). Postcafeteria male but not female rats still showed the tendency to have increased UCP3 mRNA levels relative to their age-matched controls. A linear regression analysis showed a significant positive correlation of the UCP3 mRNA levels with overweight and with serum levels of leptin and insulin in males, but not in females, and no correlation with serum free fatty acid levels. A subsequent correlation analysis and a multiple linear regression analysis showed that overweight was the only parameter actually related to UCP3 mRNA levels in males. Fasting-induced upregulation of muscle UCP3 mRNA levels was higher in males (5- to 7-fold) than in females (3- to 4-fold). Our results point to the existence of sex-associated differences in the control of muscle UCP3 expression in response to overweight and fasting, with an impaired induction in female rats under both conditions. The correlation of abdominal muscle UCP3 mRNA expression with overweight in males could be related to their relative resistance to gain weight after chronic overeating of a cafeteria diet, by the purported role of UCP3 in the regulation of lipid utilization.     

Chronic Administration of Proanthocyanidins or Docosahexaenoic Acid Reversess the Increase of miR-33a and miR-122 in Dyslipidemic Obese Rats

miR-33 and miR-122 are major regulators of lipid metabolism in the liver, and their deregulation has been linked to the development of metabolic diseases such as obesity and metabolic syndrome. However, the biological importance of these miRNAs has been defined using genetic models. The aim of this study was to evaluate whether the levels of miR-122 and miR-33a in rat liver correlate with lipemia in nutritional models. For this purpose, we analyzed the levels of miRNA-33a and miR-122 in the livers of dyslipidemic cafeteria diet-fed rats and of cafeteria diet-fed rats supplemented with proanthocyanidins and/or ω-3 PUFAs because these two dietary components are well-known to counteract dyslipidemia. The results showed that the dyslipidemia induced in rats that were fed a cafeteria diet resulted in the upregulation of miR-33a and miR-122 in the liver, whereas the presence of proanthocyanidins and/or ω-3 PUFAs counteracted the increase of these two miRNAs. However, srebp2, the host gene of miR-33a, was significantly repressed by ω-3 PUFAs but not by proanthocyanidins. Liver mRNA levels of the miR-122 and miR-33a target genes, fas and pparβ/δ, cpt1a and abca1, respectively, were consistent with the expression of these two miRNAs under each condition. Moreover, the miR-33a and abca1 levels were also analyzed in PBMCs. Interestingly, the miR-33a levels evaluated in PBMCs under each condition were similar to the liver levels but enhanced. This demonstrates that miR-33a is expressed in PBMCs and that these cells can be used as a non-invasive way to reflect the expression of this miRNA in the liver. These findings cast new light on the regulation of miR-33a and miR-122 in a dyslipidemic model of obese rats and the way these miRNAs are modulated by dietary components in the liver and in PBMCs.     

The effects of a constant T3 level and thermoneutrality in diet-induced hyperphagia

Rats were thyroidectomized, then fitted with a miniosmotic pump infusing T3, thereby assuring a constant circulating level of T3. After a ten-day recovery period, they were submitted either to a chow or to a cafeteria diet. Body weight, food intake, and energy expenditure were recorded during a thirty day period. Thyroidectomized T3 supplemented rats did not exhibit hyperphagia when fed a cafeteria diet. Despite this puzzling normophagia, they still chose nutrients in a distribution similar to that of other cafeteria-fed rats and, though maintaining the same weight as chow-fed rats, increased their proportion of fatty weight compared to these rats. The relationship between energy expenditure, T3 concentration, and cafeteria diet are discussed.