The effects of catechin rich teas and caffeine on energy expenditure and fat oxidation: a meta-analysis.

Different outcomes of the effect of catechin-caffeine mixtures and caffeine-only supplementation on energy expenditure and fat oxidation have been reported in short-term studies. Therefore, a meta-analysis was conducted to elucidate whether catechin-caffeine mixtures and caffeine-only supplementation indeed increase thermogenesis and fat oxidation. First, English-language studies measuring daily energy expenditure and fat oxidation by means of respiration chambers after catechin-caffeine mixtures and caffeine-only supplementation were identified through PubMed. Six articles encompassing a total of 18 different conditions fitted the inclusion criteria. Second, results were aggregated using random/mixed-effects models and expressed in terms of the mean difference in 24 h energy expenditure and fat oxidation between the treatment and placebo conditions. Finally, the influence of moderators such as BMI and dosage on the results was examined as well. The catechin-caffeine mixtures and caffeine-only supplementation increased energy expenditure significantly over 24 h (428.0 kJ (4.7%); P < 0.001 and 429.1 kJ (4.8%); P < 0.001, respectively). However, 24 h fat oxidation was only increased by catechin-caffeine mixtures (12.2 g (16.0%); P < 0.02 and 9.5 g (12.4%); P = 0.11, respectively). A dose-response effect on 24 h energy expenditure and fat oxidation occurred with a mean increase of 0.53 kJ mg(-1) (P < 0.01) and 0.02 g mg(-1) (P < 0.05) for catechin-caffeine mixtures and 0.44 kJ mg(-1) (P < 0.001) and 0.01 g mg(-1) (P < 0.05) for caffeine-only. In conclusion, catechin-caffeine mixtures or a caffeine-only supplementation stimulates daily energy expenditure dose-dependently by 0.4-0.5 kJ mg(-1) administered. Compared with placebo, daily fat-oxidation was only significantly increased after catechin-caffeine mixtures ingestion.

Oolong tea does not improve glucose metabolism in non-diabetic adults.

BACKGROUND: Studies of the influence of tea on glucose metabolism have produced inconsistent results, possibly because of the lack of dietary control and/or unclear characterization of tea products. METHODS: Therefore, a double-blind crossover study was conducted in which healthy males (n = 19) consumed each of three oolong tea products or a control beverage as part of a controlled diet. Treatment beverages (1.4 l/day) were consumed for 5 days, followed by assessment of fasting plasma glucose, fasting serum insulin and an oral glucose tolerance test. Tea products included oolong tea, oolong tea with added catechins and oolong tea with added oolong tea polyphenols, and control beverages included caffeinated water and unsupplemented water. On the fifth day of each treatment period, treatment beverages were consumed with a standardized meal, and glucose and insulin responses were assessed for 240 min. RESULTS: No significant differences were detected for fasting plasma glucose, fasting serum insulin, incremental plasma glucose area under the concentration time curve (AUC), total plasma glucose AUC or total serum insulin AUC. CONCLUSIONS: Neither oolong tea nor oolong tea supplemented with catechins or other polyphenols produced improved glucose metabolism in healthy adult volunteers on the basis of this highly controlled dietary intervention trial.

Identifying sources of reporting error using measured food intake.

OBJECTIVE: To investigate the magnitude and relative contribution of different sources of measurement errors present in the estimation of food intake via the 24-h recall technique. DESIGN: We applied variance decomposition methods to the difference between data obtained from the USDA's Automated Multiple Pass Method (AMPM) 24-h recall technique and measured food intake (MFI) from a 16-week cafeteria-style feeding study. The average and the variance of biases, defined as the difference between AMPM and MFI, were analyzed by macronutrient content, subject and nine categories of foods. SUBJECTS: Twelve healthy, lean men (age, 39+/-9 year; weight, 79.9+/-8.3 kg; and BMI, 24.1+/-1.4 kg/m2). RESULTS: Mean food intakes for AMPM and MFI were not significantly different (no overall bias), but within-subject differences for energy (EI), protein, fat and carbohydrate intakes were 14, 18, 23 and 15% of daily intake, respectively. Mass (incorrect portion size) and deletion (subject did not report foods eaten) errors were each responsible for about one-third of the total error. Vegetables constituted 8% of EI but represented >25% of the error across macronutrients, whereas grains that contributed 32% of EI contributed only 12% of the error across macronutrients. CONCLUSIONS: Although the major sources of reporting error were mass and deletion errors, individual subjects differed widely in the magnitude and types of errors they made.

The impact of the covert manipulation of macronutrient intake on energy intake and the variability in daily food intake in nonobese men.

OBJECTIVE: To investigate the effect of macronutrient composition on ad libitum food intake in nonobese men. DESIGN: Balanced, incomplete-block, crossover study where subjects received two of three treatments. Macronutrient composition was manipulated by providing 2.1 MJ/day high-carbohydrate (CHO), high-fat (FAT), and/or high-protein (PRO) drinks every day over the course of two, 8-week periods. SUBJECTS: In all, 12 healthy normal weight men (age: 39+/-9 years, BMI: 24.1+/-1.4 kg/m2). MEASUREMENTS: Ad libitum food intake was measured continuously for 16 weeks at the Beltsville Human Nutrition Research Center (BHNRC). Body composition (DEXA) and body weight were also measured. RESULTS: Average energy intake (EI) during weeks 1 and 2 was lower for CHO than FAT (P<0.05), but this effect disappeared by week 3. EI during CHO increased by 11% from week 1 to 8 through the increased selection of carbohydrate and protein-containing foods, but not fat foods. Food intake was variable, both between and within subjects, but was not related to macronutrient composition. CONCLUSION: EI appears to be influenced by macronutrient composition in the short-term when diets are modified, but the effect dissipates in a few weeks if the diet is maintained. These data suggest the presence of macronutrient-specific regulatory mechanisms in the body, but do not support the notion that a high intake of any of the three macronutrients suppresses EI over a prolonged period of time. The high variability in food intake does not appear to be related to macronutrient composition.

Oolong tea increases metabolic rate and fat oxidation in men.

According to traditional Chinese belief, oolong tea is effective in the control of body weight. Few controlled studies, however, have been conducted to measure the impact of tea on energy expenditure (EE) of humans. A randomized cross-over design was used to compare 24-h EE of 12 men consuming each of four treatments: 1) water, 2) full-strength tea (daily allotment brewed from 15 g of tea), 3) half-strength tea (brewed from 7.5 g tea) and 4) water containing 270 mg caffeine, equivalent to the concentration in the full-strength tea treatment. Subjects refrained from consuming caffeine or flavonoids for 4 d prior to the study. Tea was brewed each morning; beverages were consumed at room temperature as five 300 mL servings. Subjects received each treatment for 3 d; on the third day, EE was measured by indirect calorimetry in a room calorimeter. For the 3 d, subjects consumed a typical American diet. Energy content of the diet was tailored to each subject's needs as determined from a preliminary measure of 24-h EE by calorimetry. Relative to the water treatment, EE was significantly increased 2.9 and 3.4% for the full-strength tea and caffeinated water treatments, respectively. This increase over water alone represented an additional expenditure of 281 and 331 kJ/d for subjects treated with full-strength tea and caffeinated water, respectively. In addition, fat oxidation was significantly higher (12%) when subjects consumed the full-strength tea rather than water.

Diet interviews of subject pairs: how different persons recall eating the same foods.

OBJECTIVE: To compare qualitative descriptions of the same food items eaten by different persons using 24-hour dietary recall interviews. DESIGN: Eleven pairs of subjects were interviewed twice using 24-hour dietary recalls such that each member of the pair described the same day's foods. Each pair shared a home and ate at least 2 meals together daily. After each interview, subjects were asked to identify the foods reported during the interview that they observed the other member of their pair consuming and to note when a particular food was the only item of that type available in the house. Qualitative descriptions of the foods were compared, differences in descriptions were noted, and calculations were made of the potential energy error produced if a subject erred in reporting a food item. SUBJECTS/SETTING: Subjects were randomly selected from a database of persons who have participated in other studies at the Beltsville Human Nutrition Research Center. Ten pairs were husbands and wives and 1 pair was sisters. Each pair reported eating at least 2 meals per day together. Dietary recall interviews were done at the Research Center and were conducted by a trained dietitian in a quiet room free of distractions. RESULTS: Discrepancies in qualitative food descriptions were identified for every subject pair interviewed. Men were found to be more likely to omit food items than women, snack items were more likely to be omitted than meal items, meat items were likely to be described inaccurately, and first interviews were likely to contain more errors than second interviews. APPLICATIONS/CONCLUSIONS: This analysis shows which types of food items are most likely to be omitted or inaccurately described, and that dietetics professionals may improve the accuracy of dietary intake interviews by asking questions related to meat, milk, and snacks very carefully. The analysis also showed reductions in recall inconsistencies from the first recall to the second recall, suggesting that the learning associated with repeated interviews may be helpful in accurately identifying what a person consumes.

Accuracy and precision of dual-energy X-ray absorptiometry for body composition measurements in rhesus monkeys.

Accuracy of body composition measurements by dual-energy X-ray absorptiometry (DXA) was compared with direct chemical analysis in 10 adult rhesus monkeys. DXA was highly correlated (r-values > 0.95) with direct analyses of body fat mass (FM), lean mass (LM) and lumbar spine bone mineral content (BMC). DXA measurements of total body BMC were not as strongly correlated (r-value = 0.58) with total carcass ash content. DXA measurements of body FM, LM and lumbar spine BMC were not different from data obtained by direct analyses (P-values > 0.30). In contrast, DXA determinations of total BMC (TBMC) averaged 15%, less than total carcass ash measurements (P = 0.002). In conclusion, this study confirms the accurate measurement of fat and lean tissue mass by DXA in rhesus monkeys. DXA also accurately measured lumbar spine BMC but underestimated total body BMC as compared with carcass ash determinations.

Changes in women's plasma lipid and lipoprotein concentrations due to moderate consumption of alcohol are affected by dietary fat level.

We studied the impact of substituting ethanol for dietary carbohydrate, in high- and low-fat diets, on plasma lipids and lipoprotein concentrations. During a 12-wk, weight maintaining, controlled feeding study, women consumed only food and beverage provided by the Human Studies Facility of the USDA Beltsville Human Nutrition Research Center. Twenty-six women (age 41-59 y) consumed either a high-fat diet (38% of energy from fat) or a low-fat diet (18% of energy from fat) for 12 wk. The 12-wk feeding period was divided into two 6-wk periods in a cross-over design during which either ethanol or carbohydrate was added to the diet (5% of total daily energy intake). When the women consuming the high-fat diet had ethanol added to their diet, they had 6% lower plasma cholesterol (P = 0.003), 11% lower LDL cholesterol (P = 0.001) and 3% higher HDL cholesterol (P = 0.06) than when they had an equal amount (% energy) of carbohydrate added to their diet. The greater HDL cholesterol concentration was due to a 21% greater the HDL(2) subfraction (P = 0. 001). The ratio of LDL to HDL cholesterol was 14% lower. No significant differences existed in plasma lipids in women consuming the low-fat diet between the periods in which they had ethanol or carbohydrate added to their diet. This study suggests that the decreases in cardiovascular disease risk factors typically seen with moderate alcohol consumption may not be evident in individuals consuming a diet low in fat. Therefore changes in the risk factors associated with a low-fat diet and moderate alcohol consumption do not appear to be additive.

Energy available from corn oil is not different than that from beef tallow in high- or low-fiber diets fed to humans.

The impact of the source of dietary fat and the level of dietary fiber on digestibility and energy metabolism were studied in human (six male, six female) volunteers. Subjects were divided into two diet treatment groups, high fiber [29.0 g total dietary fiber (TDF)/d] and low fiber (18.6 g TDF/d), for the duration of the study. Each participated in three, 2-wk controlled feeding periods. Either beef tallow (BT), corn oil (CO) or carbohydrate (CHO) was added (25% of diet energy) to a base diet in a three-way crossover study. Energy expenditure, substrate oxidation and digestibility determinations were conducted at the end of each period. The protein, fat and CHO digestibility of the base diet was significantly different between the fiber levels. The digestibility (high-fiber/low-fiber) averaged 82%, 90% for protein, 96% and 98% for fat. After adjusting for TDF, the CHO digestibility averaged 96% and was not different between fiber levels. The digestibility of the added CO and BT was 99.6 and 99.8% respectively, and was not significantly different between the fiber levels. No significant differences in 24-h energy expenditure existed nor the thermic effect of food due either to fiber level or between the CHO, BT or CO. Fat oxidation in subjects consuming the low-fiber diet was 14% higher (P < 0.03) with the BT treatment than with the CO treatment but not different in those that consumed the high-fiber diet. The energy value of the two fat sources was not different but their utilization by individuals near energy balance may lead to differences in long-term weight maintenance.

Dietary fiber influences nutrient utilization, growth and dry matter intake of green iguanas (Iguana iguana).

Herbivory is an uncommon feeding strategy in lizards. Appropriate diet formulations for captive lizards should be based on performance measures, yet few data are available on the effect of plant fiber on food intake, nutrient utilization and growth of captive herbivorous lizards. This study was conducted to determine the effect of three levels of dietary fiber on dry matter intake, nutrient and energy metabolizability and growth rate of the green iguana (Iguana iguana). Twenty-one captive iguanas were fed nutritionally complete diets containing three levels of dietary fiber: 19, 24, and 27% neutral detergent fiber. The iguanas were fed each diet for at least 12 wk, and total excreta were collected for 11.3 +/- 4.0 d (means +/- , range of 7 to 25 d). Diets and excreta were analyzed for dry matter, organic matter, gross energy, neutral detergent fiber, acid detergent fiber, and acid detergent lignin. The study was designed as a Latin square crossover. Across all diets, dry matter intake was proportional to body mass1.0 (BM). Growth rate was greater (P < 0. 05) when iguanas were fed the low and medium fiber diets (2.2 and 2. 4 g/d, respectively) than when fed the high fiber diet (1.4 g/d). However, mean daily dry matter intake of the three diets [7.2 g/(d. kg BM)] was not different. In general, digestibility of fiber fractions and the metabolizability of dietary energy decreased (P < 0.05) as the level of dietary fiber increased. These data suggest that a diet containing less than 27% neutral detergent fiber should be fed if rapid growth is to be sustained during intensive captive production of green iguanas.

Dietary fiber decreases the metabolizable energy content and nutrient digestibility of mixed diets fed to humans.

Food labeling regulations implemented by the U.S. Food and Drug Administration emphasize nutrient composition and energy content of foods. Dietary energy and digestibility of complex foods can be affected by the content and type of dietary fiber. The metabolizable energy (ME) content and apparent digestibility of dietary fiber in human diets are difficult to assess. Fiber can affect the digestibility of fat and protein and, subsequently, the ME content of the diet. This study was conducted to measure the ME content of nine diets with different fat and fiber concentrations. Diets varied in level of fat (18, 34 or 47% of energy) and level of total dietary fiber (3, 4 or 7% of diet dry matter) and were consumed for 2 wk. Subjects (n = 17) consumed three diets (14 d for each diet) containing different levels of fiber and one level of fat. Food consumption was measured and all urine and feces were collected during a 5-d period. Combustible energy, protein, fat, total dietary fiber (TDF) and neutral detergent fiber (NDF) were measured in composite samples of food and feces, and urine was analyzed for combustible energy and nitrogen. Metabolizable energy and apparent digestibility coefficients were calculated. Overall, increasing fiber intake decreased fat and protein digestibility. As a consequence of these interactions, the ME content of the diets decreased as fiber intake increased, and TDF and NDF had similar effects on the ME value. A published empirical formula accurately predicted the ME content of diets using either TDF or NDF.

Synchronous direct gradient layer and indirect room calorimetry.

A dual direct/indirect room-sized calorimeter is used at the Beltsville Human Nutrition Research Center to measure heat emission and energy expenditure in humans. Because the response times of a gradient layer direct calorimeter and an indirect calorimeter are not equivalent, the respective rate of heat emission and energy expenditure cannot be directly compared. A system of equations has been developed and tested that can correct the respective outputs of the direct gradient layer calorimeter and indirect calorimeter for delays due to the response times of the measurement systems. Performance tests using alcohol combustion to simulate a human subject indicate accurate measurements of heat production from indirect (99.9 +/- 0.4%), indirect corrected for response time (99.9 +/- 0.5%), direct (99.9 +/- 0.8%), and direct corrected for response time (99.9 +/- 0.8%) calorimetry systems. Results from 24-h measurements in 10 subjects indicate that corrected heat emission is equivalent to (99.8 +/- 2.0%) corrected energy expenditure. However, heat emission measured during sleep was significantly greater (14%) than energy expenditure, suggesting a change in the energy stored as heat in the body. This difference was reversed during the day. These results illustrate how the simultaneous measurement of heat emission and energy expenditure provides insights into heat regulation.

Comparison of energy expenditure measurements by diet records, energy intake balance, doubly labeled water and room calorimetry.

OBJECTIVES: The purpose of this study was to compare estimates of daily energy expenditure (EE) using energy intake from self reported diet records, metabolizable energy intake balance, doubly labeled water and room calorimetry methods. DESIGN: Cross sectional design. SETTING: Beltsville Human Nutrition Research Center, Beltsville, MD USA. INTERVENTIONS: Energy intake was measured using seven-day self reported diet records (EI), and metabolizable energy (ME) intake balance. EE was measured using doubly labeled water (TEE) and 24 h indirect room calorimetry (24 EE). Body composition was measured using stable isotope dilution and DEXA. RESULTS: EI measured by self reported diet records was 22% less than ME intake balance, 23% less than TEE by doubly labeled water and 8% less than 24 EE by room calorimetry. 24 EE was 16% less than TEE and 16% less than ME. TEE was not significantly greater than ME (0.3%). While mean ME, TEE and 24 EE measurements were significantly lower in female compared to male subjects, mean EI and the mean percent difference between measurement methods were not. CONCLUSIONS: Direct comparison of these methods indicate self reported diet records and room calorimetry underestimate daily energy expenditure. While EI balance accurately estimates energy expenditure, EE measured by doubly labeled water is a more direct approach.

Dietary starch composition and level of energy intake alter nutrient oxidation in "carbohydrate-sensitive" men.

The effect of dietary starch type on components of 24-h energy expenditure (total, sleep, exercise) were examined in 13 hyperinsulinemic and nine control men, aged 28-58 y. Subjects consumed products containing 70% amylopectin or 70% amylose cornstarch for two 14-wk periods in a crossover design. A 10-wk period of starch replacement in the subjects' self-selected diets was followed by a 4-wk controlled feeding period at 100% maintenance energy intake; diets during the last 4 d of the controlled feeding period provided excess energy, i.e., 125% of maintenance energy. Data for insulin, glucose, 24-h energy expenditure and its components, respiratory quotient and nutrient oxidation were analyzed by ANOVA for mixed models. Although insulin and glucose responses to a starch tolerance test remained greater for hyperinsulinemic than for control subjects, both were reduced with high amylose consumption (P < 0.04). No component of energy expenditure was significantly affected by dietary starch or subject type. However, excess energy intake did increase metabolic energy expenditure (P < 0.0001). Protein oxidation increased with excess energy intake when subjects consumed the high amylopectin starch but did not increase in response to excess energy consumption when the high amylose diet was consumed, suggesting increased protein retention. The magnitude of the response in carbohydrate and fat oxidation was blunted in hyperinsulinemic subjects consuming excess levels of the amylose diet. This may be due to an improvement in overall insulin response or to a change in available substrates for oxidation resulting from microbial fermentation.

Energy value of moderate alcohol consumption by humans.

We investigated the effects of an equal-energetic substitution of ethanol for dietary carbohydrate in high-and low-fat diets on energy expenditure and body composition. During the controlled feeding study, subjects maintained their weights and consumed only food and drink provided by the US Department of Agriculture Beltsville Human Nutrition Research Center's Diet Study Facility. Subjects (16 men and 32 women) were divided equally into two groups and consumed either a high-or low-fat diet for 16 wk. The feeding period was divided into two 8-wk periods during which either ethanol or carbohydrate was added to the diet (5% of total daily energy intake) in a crossover design. The metabolizable energy content of the diets (with supplements) was determined for all subjects through measurement of total food intake and fecal and urinary losses for 7 d during both 8-wk periods. Energy expenditure, measured for 24 h in a room calorimeter at the end of each 8-wk period, was the same for both periods. Metabolizable energy intake and changes in total-body energy content were used to calculate the total amount of energy expended by each subject for 7 wk during each 8-wk period. Total energy expenditure for 7 wk was the same when subjects consumed either ethanol or carbohydrate. These data clearly show that on an energy basis ethanol and carbohydrate are utilized in the diet with the same efficiency. These data are consistent with the efficiency of use of alcohol for maintenance of metabolizable energy being the same as that for carbohydrate.

Calorie restriction lowers body temperature in rhesus monkeys, consistent with a postulated anti-aging mechanism in rodents.

Many studies of caloric restriction (CR) in rodents and lower animals indicate that this nutritional manipulation retards aging processes, as evidenced by increased longevity, reduced pathology, and maintenance of physiological function in a more youthful state. The anti-aging effects of CR are believed to relate, at least in part, to changes in energy metabolism. We are attempting to determine whether similar effects occur in response to CR in nonhuman primates. Core (rectal) body temperature decreased progressively with age from 2 to 30 years in rhesus monkeys fed ad lib (controls) and is reduced by approximately 0.5 degrees C in age-matched monkeys subjected to 6 years of a 30% reduction in caloric intake. A short-term (1 month) 30% restriction of 2.5-year-old monkeys lowered subcutaneous body temperature by 1.0 degrees C. Indirect calorimetry showed that 24-hr energy expenditure was reduced by approximately 24% during short-term CR. The temporal association between reduced body temperature and energy expenditure suggests that reductions in body temperature relate to the induction of an energy conservation mechanism during CR. These reductions in body temperature and energy expenditure are consistent with findings in rodent studies in which aging rate was retarded by CR, now strengthening the possibility that CR may exert beneficial effects in primates analogous to those observed in rodents.

[Duplex sonography in functional thyroid diagnosis]. / Die Duplexsonographie in der Schilddrüsenfunktionsdiagnostik.

PURPOSE: Assessment of the functional diagnostic value of Doppler sonographic or sonographic parameters, especially of the peak flow velocity in the inferior thyroid artery in patients with newly manifest autoimmunothyroiditis. MATERIAL AND METHOD: Morphological and Doppler sonographic measurements were done at the inferior thyroid artery on 69 patients suffering from newly manifest Graves' disease or Hashimoto's thyroiditis, as well as on a control group of 18 subjects. The measured data were correlated with thyroid hormone levels and with quantitative scintiscanning. RESULTS: A linear functional correlation was found between the peak flow velocities in the inferior thyroid artery and the fT3 or fT4 level. If the peak flow velocities were greater than 1.2 m/s, hyperthyroid metabolism prevailed, whereas at velocities below 0.3 m/s latent hypothyroidism was present. CONCLUSION: These results show that Doppler sonography of the inferior thyroid artery can supply pointers (capable of being recorded) to the state of functioning of the thyroid even before knowing the laboratory parameters.

Decreased protein synthesis during dry saturation diving.

Changes in metabolism during saturation dives have been reported; however, these changes have not been well defined. This study was conducted to determine the effect of saturation diving on protein metabolism. Whole body protein synthesis was measured by the ammonia and urea endpoint methods, following a single oral dose of 15N-glycine in 11 Navy divers 33.9 +/- 1.9 yr of age. The divers were fed a controlled diet throughout the three trials. Trial I was on the surface, and trials II and III were during dry saturation dives at 0.56 MPa. The protein synthesis results in gram protein per kilogram lean body mass per day, least square mean +/- SD: [formula: see text]. Under the conditions of this series of dry saturation dives, protein synthesis was depressed by up to 30-50% for the urea and ammonia endpoint methods, respectively. An estimate of liver protein synthesis was made by measuring the incorporation of the 15N label into plasma fibrinogen. The 15N enrichment of fibrinogen glycine and the hippurate precursor for fibrinogen were decreased significantly. This dramatic decrease in protein synthesis was observed despite positive nitrogen balance in these divers. Although further investigation is needed to elucidate the mechanism, the decrease in the incorporation of 15N glycine into fibrinogen suggests alteration in liver nitrogen metabolism at 0.56 MPa.

Energy balance in rhesus monkeys (Macaca mulatta) subjected to long-term dietary restriction.

Male rhesus monkeys of various age groups representative of the species life span were fed ad libitum amounts (controls) or 30% less food than control monkeys of comparable age and body weight. Despite significantly lowered energy intake and body weight, the amount of energy lost in the feces, and fecal energy density (concentration) were not altered in diet-restricted (DR) monkeys, compared to age- and weight-matched controls. Absolute energy expenditure (EE; 24-hr) was consistently lower in DR monkeys, but this trend was not statistically significant. Expressed as a function of metabolic mass (body weight, metabolic body size, lean mass), 24-hr EE was not different in monkeys subjected to long-term DR, compared to controls. Calculations of net energy (intake-loss), as an index of energy balance, revealed that energy expenditure generally exceeded energy intake in all juvenile and adult group monkeys. However, this discrepancy was not statistically different from zero, suggesting that most animals were in energy balance. Also, there was no difference between control and DR animals with respect to energy balance. Diet restriction induced significant reductions in the absolute amount of lean body mass; however, percent (of total weight) lean and fat mass did not differ from controls.