Differences in segmental fat accumulation patterns by sex and ethnicity: An international approach.

Excess fat on the body impacts obesity-related co-morbidity risk; however, the location of fat stores affects the severity of these risks. The purpose of this study was to examine segmental fat accumulation patterns by sex and ethnicity using international datasets. An amalgamated and cross-calibrated dataset of dual x-ray absorptiometry (DXA)-measured variables compiled segmental mass for bone mineral content (BMC), lean mass (LM), and fat mass (FM) for each participant; percentage of segment fat (PSF) was calculated as PSFsegment = (FMsegment/(BMCsegment + LMsegment + FMsegment)) × 100. A total of 30 587 adults (N = 16 490 females) from 13 datasets were included. A regression model was used to examine differences in regional fat mass and PSF. All populations followed the same segmental fat mass accumulation in the ascending order with statistical significance (arms < legs < trunk), except for Hispanic/Latinx males (arms < [legs = trunk]). Relative fat accumulation patterns differed between those with greater PSF in the appendages (Arab, Mexican, Asian, Black, American Caucasian, European Caucasian, and Australasian Caucasian females; Black males) and those with greater PSF in the trunk (Mexican, Asian, American Caucasian, European Caucasian, and Australasian Caucasian males). Greater absolute and relative fat accumulation in the trunk could place males of most ethnicities in this study at a higher risk of visceral fat deposition and associated co-morbidities.

Low-quality protein modulates inflammatory markers and the response to lipopolysaccharide insult: the case of lysine.

The relationship between non-communicable diseases and eating behaviour has long been attributed to a surplus of food and energy. However, the increase in the prevalence of non-communicable disease and their underlying low-grade inflammatory milieu among people of low socio-economic status has highlighted the existence of a confounding factor. In this work, we aim to study the effect of lysine deficiency on some inflammatory markers in the absence or presence of an inflammatory insult (lipopolysaccharide (LPS)). For this purpose, thirty-two 5-week-old male Sprague Dawley rats were randomly distributed into four groups: (1) control diet, (2) control diet+LPS, (3) lysine-deficient diet and (4) lysine-deficient diet + LPS. Groups were only allowed their experimental diets for 4 weeks, during which LPS (50 µg/kg) or saline injections were administered intraperitoneally three times per week. The study showed that lysine deficiency blunted growth and body compartments development, decreased albumin production and elevated liver C-reactive protein (CRP) expression, independently of IL-6 and IL-1ß, the main precursors of CRP. Also, the insufficient levels of lysine in the diet increased hyperactivity and triggered an anxiety-like behaviour, exacerbated with LPS. This work presents evidence that various physiological changes are associated with the absence of a sufficient amount of lysine in the diet and can potentially increase the risk factor for diseases. Thus, the increment in non-communicable disease among the low socio-economic status populations, who heavily rely on cereals as a main source of protein, can be, at least partially, blamed on low lysine availability in diets.

The effect of aspartame and sucralose intake on body weight measures and blood metabolites: role of their form (solid and/or liquid) of ingestion.

The ingestion of non-caloric sweeteners (NCS) from food and/or drink was intended to reduce caloric intake without compromising palatability. However, the inconclusive relation between NCS and body weight may partially relate to their form of ingestion (solid or liquid). Thus, two paralleled experiments (aspartame and sucralose) were conducted. In each, Sprague Dawley rats (7-week-old male) were randomly divided into four groups. In Expt 1, aspartame (0·05 %) was added to the diet (AD) or drinking water (AW) or both diet and water (ADW), and a control group (C) was given a non-sweetened diet with plain water. In Expt 2, sucralose (0·016 %) was similarly provided in the diet (SD) or drinking water (SW) or both diet and water (SDW), with a control group (C). All rats had free access to food and water for 7 weeks. Energy intake, body weight and body composition were monitored and blood metabolites were determined. Results showed that aspartame ingestion significantly increased body weight and fat mass mainly due to an increase in energy efficiency. The effect was related to the amount rather than the form of ingestion. Additionally, aspartame ingestion was associated with glucose intolerance. Sucralose ingestion had a similar impact to that of aspartame though to a lesser extent. In conclusion, 7-week ingestion of aspartame and sucralose had adverse effects on body measures that were not related to the form of ingestion.

Iron Fortification and Supplementation: Fighting Anemia of Chronic Diseases or Fueling Obesity?

The significant worldwide increase in obesity has become a major health problem. Excess adiposity has been extensively linked to inflammation. Recently, studies have shown that dietary intake and microbiota dysbiosis can affect the health of the gut and lead to low-grade systemic inflammation, worsening the state of obesity and further exacerbating inflammation. The latter is shown to decrease iron status and potentially increase the risk of anemia by inhibiting iron absorption. Hence, anemia of obesity is independent of iron intake and does not properly respond to increased iron ingestion. Therefore, countries with a high rate of obesity should assess the health impact of fortification and supplementation with iron due to their potential drawbacks. This review tries to elucidate the relation between inflammation and iron status to better understand the etiology of anemia of obesity and chronic diseases and wisely design any dietary or medical interventions for the management of anemia and/or obesity.

Breakfast consumption among Saudi primary-school children relative to sex and socio-demographic factors.

BACKGROUND: Breakfast is an important meal that provides essential nutrients and energy. However, few comprehensive studies have reported breakfast habits and related behaviors among Saudi children. This study investigated breakfast consumption patterns and the associations of socio-demographic variables with daily breakfast intake among Saudi children. METHODS: A multistage stratified cluster random sampling technique was used to select 1051 elementary school boys and girls in Riyadh. Body weight and height were measured and body mass index (BMI) was computed. The breakfast eating habits and behaviors were assessed using a specifically designed self-reported questionnaire that was completed by the children's parents. RESULTS: More than 79% of children skipped daily breakfast, with no significant sex difference. Children in private schools consumed breakfast more frequently than those attending public schools. Multivariate analyses showed that boys in private schools had a significantly higher intake of breakfast than that in boys in public schools, yet, boys in public schools had significantly higher BMI than boys in private schools. Using logistic regression while adjusting for confounders showed insignificant effect for parent education. Among breakfast eaters, spread cheese sandwiches were consumed most frequently, followed by fried egg sandwiches and breakfast cereals. Full-fat milk, tea with milk, water, and fruit juice were the most consumed drinks. Girls consumed significantly more fresh fruits during breakfast than did boys. Mothers prepared breakfast at home most of the time (84.5%). Parents appeared mostly satisfied with the breakfast consumed by their child at home and placed high importance on breakfast compared to lunch or dinner. CONCLUSIONS: The proportion of school children who ate daily breakfast at home was low, which may have implications for children's school performance. Effort is needed to promote daily breakfast consumption among Saudi school children and to introduce appropriate interventions aimed at promoting daily breakfast consumption among Saudi children.

Insufficient Sleep Duration And Its Association With Breakfast Intake, Overweight/Obesity, Socio-Demographics And Selected Lifestyle Behaviors Among Saudi School Children.

OBJECTIVE: Adequate sleep is an important factor for maintaining good health among children. However, there have been few studies reporting on the association of sleep duration with breakfast intake frequency. This study examined the prevalence of nocturnal sleep duration among Saudi children and its association with breakfast intake, screen time, physical activity levels and socio-demographic variables. METHODS: A multistage stratified cluster random sampling technique was used to select 1051 elementary school children in Riyadh. Weight and height were measured and body mass index was computed. The sleep duration, daily breakfast intake frequency, socio-demographic and lifestyle behaviors were assessed using a specifically designed self-reported questionnaire filled by the children's parents. RESULTS: Over 71% of the Saudi school children did not attain the recommended sufficient sleep duration at night. Results of logistic regression analysis, adjusted for confounders, exhibited significant associations between longer sleep duration and younger age (aOR=1.12, p=0.046), being female (aOR=1.39, p=0.037), higher father educational levels, daily breakfast intake (aOR=1.44, p=0.049) and lower screen time (aOR for >2 hrs/day=0.69, p=0.033). However, no significant (p> 0.05) association was found for mother education, family income, number of family member in the house, overweight/obesity, or physical activity levels. CONCLUSION: The prevalence of insufficient nocturnal sleep among Saudi children was high. Insufficient sleep was associated with breakfast and several important socio-demographic and lifestyle behaviors. The findings of this study support the development of interventions to prevent insufficient sleep and help Saudi children improve their sleeping habits.

Effect of Meal Acceptability on Postprandial Appetite Scores and Hormones of Male Participants with Varied Adiposity.

OBJECTIVE: This study portrays the effect of hedonic manipulation (high acceptability [HA] vs. low acceptability [LA]) on postprandial hormones and appetite scores in healthy males. METHODS: Thirty participants (15 with normal weight and 15 with obesity) were recruited for a randomized, crossover design. They were randomly assigned to the HA or LA (with acesulfame-K) custard. Blood samples were drawn before the meals and for 4 hours after the meals and were analyzed for glucose, insulin, ghrelin, and glucagonlike peptide 1 (GLP-1). Appetite scores and subsequent energy intake were recorded. RESULTS: Postprandial glucose, insulin, and ghrelin were different according to adiposity, whereas meal acceptability did not correspond to any significant difference in postprandial glucose, insulin, ghrelin, and GLP-1 concentrations. Appetite scores showed lower hunger, higher satiety, and fullness after the HA meal without a significant difference between the meals. Subsequent energy intake, expressed as a percentage of the resting energy expenditure, was higher in participants with obesity but did not reflect postprandial hormones and appetite scores; there was no significant difference between meals. CONCLUSIONS: Hedonic properties and palatability do not affect gut hormones, mainly ghrelin and GLP-1. Moreover, their postprandial concentrations were not paralleled by similar changes in appetite scores, and both were not found to affect subsequent intake.

Phosphorus Supplementation Mitigated Food Intake and Growth of Rats Fed a Low-Protein Diet.

Background: Low protein intake is associated with various negative health outcomes at any life stage. When diets do not contain sufficient protein, phosphorus availability is compromised because proteins are the major sources of phosphorus. However, whether mineral phosphorus supplementation mitigates this problem is unknown, to our knowledge. Objective: Our goal was to determine the impact of dietary phosphorus supplementation on food intake, weight gain, energy efficiency, body composition, blood metabolites, and liver histology in rats fed a low-protein diet for 9 wk. Methods: Forty-nine 6-wk-old male Sprague-Dawley rats were randomly allocated to 5 groups and consumed 5 isocaloric diets ad libitum that varied only in protein (egg white) and phosphorus concentrations for 9 wk. The control group received a 20% protein diet with 0.3% P (NP-0.3P). The 4 other groups were fed a low-protein (10%) diet with a phosphorus concentration of 0.015%, 0.056%, 0.1%, or 0.3% (LP-0.3P). The rats' weight, body and liver composition, and plasma biomarkers were then assessed. Results: The addition of phosphorus to the low-protein diet significantly increased food intake, weight gain, and energy efficiency, which were similar among the groups that received 0.3% P (LP-0.3P and NP-0.3P) regardless of dietary protein content. In addition, phosphorus supplementation of low-protein diets reduced plasma urea nitrogen and increased total body protein content (defatted). Changes in food intake and efficiency, body weight and composition, and plasma urea concentration were highly pronounced at a dietary phosphorus content <0.1%, which may represent a critical threshold. Conclusions: The addition of phosphorus to low-protein diets improved growth measures in rats, mainly as a result of enhanced energy efficiency. A dietary phosphorus concentration of 0.3% mitigated detrimental effects of low-protein diets on growth parameters.

Phosphorus Supplementation Recovers the Blunted Diet-Induced Thermogenesis of Overweight and Obese Adults: A Pilot Study.

Diet-induced thermogenesis (DIT) is believed to be largely related to ATP production, which is dependent on phosphorus (P) availability. We aimed to test the effect of P addition on DIT of lean and overweight/obese healthy subjects. DIT was measured with or without P in 10 lean and 13 overweight/obese adults in a double-blind randomized cross-over pilot study with one week washout period. After 10 h overnight fast, resting metabolic rate, respiratory quotient, and substrate utilization were measured at fasting and every 30 min for 3 h after subjects drank a standardized glucose solution, with P (500 mg) or placebo pills. Subjective ratings of hunger and satiety were assessed before and after the end of each experiment using validated visual analogue scale (VAS) questionnaires. Overweight/obese subjects had a blunted DIT with placebo, while P supplementation induced a 23% increase in their DIT area under the curve (p < 0.05), which was associated with a significant increase in carbohydrate oxidation. Subjects had lower appetite following P supplementation, which was expressed as a significantly (p = 0.02) lower desire to eat a meal (4.0 ± 0.7 cm) compared with placebo (5.8 ± 0.9 cm). P supplementation recovers the blunted diet-induced thermogenesis in overweight and obese subjects and enhances their postprandial satiety.

Combined fish oil and high oleic sunflower oil supplements neutralize their individual effects on the lipid profile of healthy men.

Both n-3 and n-9 fatty acids share a common metabolic pathway and can potentially and individually improve cardiovascular disease risk factors. Dietary n-6 is known to weaken the efficacy of n-3 fatty acids due to competition for the same enzymes. Still unclear is whether a similar competition exists between n-3 and n-9 fatty acids. Thus, a 12-week intervention study was conducted to investigate the effect of different combinations of fish oil and high-oleic sunflower oil (OSO) on healthy subjects. Included were five groups (98 subjects): three groups received a fixed amount of n-9 (8 g/day) with varying amounts of n-3 (1, 2 or 4 g/day), one group was given n-3 fatty acids only (2 g/day) and another was given n-9 only (8 g/day). We found that fish oil supplement (2 g/day) was able to decrease TAG by about 13 %, this effect was diminished with the co-ingestion of n-9 (OSO). Intake of OSO (8 g/day) reduced both total and LDL cholesterol by about 10 %, this effect was reduced by the addition of fish oil. Both fish oil and OSO failed to have any significant effect on both glycemic and blood pressure parameters. In conclusion; the impact of oleic acid (n-9) on total and LDL cholesterol was altered by the addition fish oil (n-3). These effects may have been the result of enzymatic competition between the two types of fatty acids.

Effect of lysine, vitamin B(6), and carnitine supplementation on the lipid profile of male patients with hypertriglyceridemia: a 12-week, open-label, randomized, placebo-controlled trial.

BACKGROUND: Fat metabolism is known to be altered in hypertriglyceridemia. Fat oxidation requires carnitine, which can be obtained either from the diet (animal or dairy products) or through synthesis in the body using both lysine and vitamin B(6). OBJECTIVE: The goal of this study was to investigate the effect of lysine, vitamin B(6), and carnitine supplementation on both glycemia and the lipid profiles, specifically triglyceride (TG) levels, in men with hypertriglyceridemia. METHODS: This 12-week, randomized, placebo-controlled clinical trial was conducted at a Lebanese medical center. A total of 85 hypertriglyceridemic (TG> 150 mg/dL) male patients were randomized to 1 of 5 groups and given supplements of lysine (1 g/d), vitamin B(6) (50 mg/d), lysine (1 g/d) + vitamin B(6) (50 mg/d), carnitine (1 g/d), or placebo for 12 weeks. The lipid profile (TG, total cholesterol, LDL-C, and HDL-C) and fasting plasma glucose levels were assessed at baseline and at 6 and 12 weeks. RESULTS: Adults (∼50 years) Lebanese males from a low socioeconomic status in Beirut were given the appropriate supplements. Vitamin B(6) supplementation was associated with a significant reduction in total cholesterol and HDL-C of ∼10%. In addition, plasma TG was reduced by 36.6 mg/dL at 6 weeks, whereas levels in the placebo group increased by 18 mg/dL; this difference failed to reach statistical significance. No major changes in the lipid profile were observed in the lysine and carnitine groups or when lysine was added to vitamin B(6). CONCLUSION: Vitamin B(6) supplementation in these male patients with hypertriglyceridemia reduced plasma total cholesterol and HDL-C concentrations.

Stimulation of postprandial in vivo glycogenesis and lipogenesis of rats fed high fructose diet with varied phosphate content.

It has been reported that increased fructose intake is associated with the development of the metabolic syndrome. The phosphate (P) sequestering capacity of fructose is likely to affect the phosphorylation capacity of different metabolites, and this, in turn, may be the basis for several metabolic derangements, especially in the P requiring reactions, for example, glycogenesis and lipogenesis. We hypothesized that P enrichment of the diet can balance P status and, consequently, affect glycogenesis and lipogenesis. An animal experiment was executed in which adult male Sprague-Dawley rats were maintained for 4 days on high-fructose diets with different P content (0.15%, 0.165%, 0.30%, and 1.65%). At the end of the feeding period, overnight fasted rats were tube fed a test meal, injected with (3)H(2)O and euthanized 1 hour later. Final plasma glucose, insulin, uric acid, and triacylglycerol concentrations, as well as in vivo rates of glycogen and lipid synthesis and hepatic glycogen content, were measured. Results showed that increased P content of the diet was associated with an increase in postprandial epididymal fat pad (P = .007) and hepatic lipogenesis (P = .029), as well as glycogenesis (P = .024). In conclusion, P content of the diet was found to stimulate both glycogenesis and lipogenesis. These alterations in carbohydrate and fat metabolism point to the potential of P in influencing nutritional status.

Acute effect of leptin and ghrelin injection on postprandial glycogen and lipid synthesis in rats.

AIM: The study was designed to investigate the immediate (1 h) effect of leptin and ghrelin injection on in vivo postprandial hepatic glycogen and lipid synthesis. ANIMALS AND METHODS: Adult Sprague-Dawley male rats were fed a semisynthetic control diet ad libitum. Overnight-fasted rats were gavaged with 4 ml of water containing 1.25 g of the diet and immediately injected intraperitoneally with 4 mCi of (3)H(2)O. After 1 h, rats were either intraperitoneally injected with saline (control), leptin (20 microg/rat) or ghrelin (10 microg/rat) and sacrificed 1 h later. Blood, liver and epididymal fat pads (EFP) were taken for analysis. RESULTS: Plasma triglyceride level was higher in the leptin group compared to control. Leptin injection reduced hepatic glycogen synthesis while glycogen accumulation was not affected and ghrelin injection did not affect hepatic glycogen synthesis. Both hepatic and EFP lipogenesis were not affected by leptin or ghrelin. CONCLUSION: Leptin and ghrelin administration had no immediate effect on hepatic and adipose tissue lipogenesis. Leptin reduced in vivo postprandial hepatic glycogenesis and increased plasma triglyceride level which may be due to reduced uptake by peripheral tissues. Thus, leptin was found to exert an immediate effect on lipid and carbohydrate metabolism unlike that of ghrelin.

Meal pattern of male rats maintained on histidine-, leucine-, or tyrosine-supplemented diet.

OBJECTIVE: Food intake is known to be affected by macronutrient composition of the diet, and protein manipulation has been reported to alter food intake, but the effect of individual amino acids on eating behavior has not been fully studied. This study investigated the effect of diet supplementation with three individual amino acids on meal pattern in male rats. RESEARCH METHODS AND PROCEDURES: Thirty-two Sprague-Dawley rats were randomly divided into four equal groups and fed control diet or histidine (5%)-, leucine (5%)-, or tyrosine (5%)-supplemented diet for 2 weeks and were monitored for their meal pattern. RESULTS: Total food intake and feeding rate of the different groups were not affected, although other components of meal pattern were altered. Histidine supplementation reduced diurnal meal size by 42% (p < 0.05), whereas that of leucine increased nocturnal meal size by approximately 35% (p < 0.05). Tyrosine supplementation increased food intake of the nocturnal period and decreased that of the diurnal period. Both histidine and tyrosine supplementation elevated fasting plasma insulin levels and suppressed fasting glucose significantly. DISCUSSION: Individual amino acids were found to alter meal pattern differently. Further investigations are required to dissect the involvement of central and peripheral factors in these alterations.

Vitamins A and E status in an urban Lebanese population: a case study at Dar Al-Fatwa area, Beirut.

Vitamin A and E status are widely studied in various populations because of their association with several diseases. Fasting plasma vitamin A and E status of 857 Lebanese adults residing in Dar Al-Fatwa, Beirut were assessed using high performance liquid chromatography (HPLC). Mean retinol and alpha-tocopherol concentrations were 59.8 +/- 29 microg/dL and 1.0 +/- 0.5 mg/dL, respectively in which only 0.2% were retinol-deficient, while 0.7% were alpha-tocopherol-deficient. Vitamin A and E correlated positively with plasma concentrations of total cholesterol, low-density lipoprotein (LDL)-cholesterol, and triglycerides. Vitamin E, but not vitamin A, correlated positively with blood pressure and glucose. A good status of vitamins A and E was found among the studied Lebanese sample and the elevation in vitamin A and E levels was associated with unfavorable lipid profile.

The effect of glutamine and dihydroxyacetone supplementation on food intake, weight gain, and postprandial glycogen synthesis in female Zucker rats.

OBJECTIVE: We sought to test the hypothesis that increasing postprandial hepatic glycogen synthesis rate would decrease food intake and growth rate in obese Zucker rats. DESIGN: Supplements of glutamine, with and without dihydroxyacetone (DHA), which have previously been shown to stimulate hepatic glycogen synthesis, were administered in the diet of obese Zucker rats for periods of 1 and 3 wk. MEASUREMENTS: Food intake and body weight were monitored throughout the experiments. At the end of the feeding period the rats were fed a test meal and injected with (3)H(2)O to measure in vivo rates of glycogen and lipid synthesis. Final plasma glucose and triacylglycerol and hepatic glycogen content were also determined. Carcass fat and water contents were also measured in the 3-wk study. RESULTS: Dietary glutamine had no effect on food intake, weight gain, or body composition. Addition of DHA caused a reduction in food intake and weight gain and a stimulation of in vivo hepatic glycogen synthesis after 1 wk, but these changes were abolished by the end of 3 wk. Hepatic lipogenesis in vivo was increased by DHA treatment for 1 and 3 wk. CONCLUSIONS: Stimulation of hepatic glycogen synthesis by DHA treatment was associated with a reduction in food intake. However, the effect of DHA on glycogen synthesis and food intake disappeared after 3 wk of supplementation.

Postprandial glycogen and lipid synthesis in prednisolone-treated rats maintained on high-protein diets with varied carbohydrate levels.

OBJECTIVE: The present experiment was designed to study the effect of a high-protein, high-carbohydrate diet versus a high-protein, low-carbohydrate diet on in vivo postprandial glycogen and lipid synthesis of rats treated with prednisolone. METHODS: Thirty-two 6-wk-old male Sprague-Dawley rats were randomly assigned to one of four equal groups: high-protein, high-carbohydrate; high-protein, high-carbohydrate with prednisolone; high-protein, low-carbohydrate; and high-protein, low-carbohydrate with prednisolone. Rats were sham operated or subcutaneously implanted with prednisolone pellets while being maintained on their respective diets (39% of energy from protein) for 6 wk. Food intake and body weight were monitored throughout the experiment. At the end of the feeding period, overnight-fasted rats were fed a test meal and injected with 3H2O to measure in vivo rates of glycogen and lipid synthesis. Final plasma glucose, insulin, and triacylglycerol concentrations and hepatic glycogen content were also measured. RESULTS: Results showed that hepatic glycogen content (milligrams per gram of liver) was similar across all four experimental groups. Total hepatic glycogen synthesis and its percentage synthesis via pyruvate (indirect pathway) were higher in rats maintained on the high-protein, high-carbohydrate diet compared with those on the high-protein, low-carbohydrate diet and this was not substantially affected by prednisolone administration. Hepatic and epididymal fat pad lipid syntheses were not altered by diet or prednisolone treatments. CONCLUSION: Under long-term high-protein conditions, prednisolone administration does not seem to affect hepatic glycogen synthesis, which was increased with the increased carbohydrate content of the diet.

Plasma amino acid concentrations in patients with coronary heart disease: a comparison between U.K. Indian Asian and Caucasian men.

The pattern of plasma free amino acids (PFAAs) of subjects with coronary heart disease (CHD) and controls was investigated. PFAA concentrations of CHD patients (29 Caucasian, 20 U.K. Indian Asian) and controls (36 Caucasian, 27 U.K. Indian Asian) were analyzed by high-performance liquid chromatography (HPLC). Plasma free alanine, tyrosine, and isoleucine concentrations were higher in U.K. Indian Asians compared with Caucasians. Plasma free alanine concentration was higher in CHD patients compared with controls, and the difference was mainly related to the presence of diabetes or elevated blood glucose in the former. Plasma free cysteine concentration was higher in CHD patients compared with controls; this does not seem to be affected by the eating habits of the two races, and seems to be a good marker for CHD and better than that of homocysteine. The data obtained in the present study showed no major alteration in PFAAs pattern in CHD patients except for that of cysteine.

Effect of diet supplementation with glutamine, dihydroxyacetone, and leucine on food intake, weight gain, and postprandial glycogen metabolism of rats.

OBJECTIVE: We tested the hypothesis that increasing the rate of postprandial hepatic glycogen synthesis would decrease food intake and growth rate in normal rats. METHODS: Diets supplemented with glutamine, glutamine plus dihydroxyacetone, and glutamine plus dihydroxyacetone plus leucine were administered to male Sprague-Dawley rats for 1 wk. These are combinations that have been shown to stimulate hepatic glycogen synthesis in vitro. Food intake and body weight were monitored throughout the experiment. At the end of the feeding period, rats were fed a test meal and injected with 3H2O to measure in vivo rates of glycogen and lipid synthesis. Positional analysis of the 3H incorporated into glycogen was used to determine the proportion of glycogen synthesized via pyruvate. Final levels of plasma glucose and triacylglycerol and hepatic glycogen were also measured. RESULTS: Dietary glutamine increased hepatic glycogen synthesis. Addition of dihydroxyacetone, with or without additional leucine, caused an additional increase in hepatic glycogen synthesis and increased the proportion of glycogen synthesized via pyruvate. Lipogenesis was not altered in the liver or adipose tissue. None of the dietary treatments had any effect on food intake, but the diets that contained dihydroxyacetone decreased the rate of weight gain. CONCLUSIONS: Increasing glycogen synthesis had no effect on food intake. Increasing the proportion of glycogen synthesized by the indirect pathway through pyruvate was associated with a decrease in weight gain.