Differential effect of common snack foods on caloric intake, growth and obesity in weanling male and female rats with hypothalamic obesity

In order to see whether weanling normophagic rats with hypothalamic obesity (VMNL rats) become hyperphagic and more obese than when fed lab chow, and to see in addition whether there is a possible sex difference in whatever response is found, male and female VMNL rats were fed lab chow for 14 days after lesion production and then, for the following 42 days, they received Hostess HoHos, potato chips, marshmallows and french fries in addition to lab chow. At termination, body weights were similar among the groups, but VMNL rats were fatter and shorter than controls. Also, female VMNL rats were fatter and shorter than male VMNL rats and layed down more fat per unit of food energy. Total caloric intake was greater in controls than in VMNL rats and in males than in females. However, the females showed a decrease in intake and the males an increase over time. Males ate more lab chow and french fries than females. Lab chow was the only food that VMNL rats ate more of than controls. The VMNL rats ate less french fries, HoHos and potato chips than controls, but similar amounts of marshmallows. There was no sex difference in macronutrient intake and per cent macronutrient intake. Moreover, controls ate as much carbohydrate and less per cent carbohydrate than VMNL rats, more fat than VMNL rats, but normal per cent fat and normal protein and per cent protein. Sex X lesion interactions indicated that female VMNL rats ate more per cent carbohydrate than female controls and male VMNL rats, ate more protein than male controls. The greater degree of obesity in the females despite the lower caloric intake may be due to enhanced food energy utilization. The data also show that weanling VMNL rats do not exhibit the great preference for palatable diets that have been reported for mature rats with ventromedial hypothalamic area lesions and that the only sex difference in intake is with french fries, which have neither the highest fat nor the highest carbohydrate content of the foods tested.     

Body cell mass in cancer-bearing and anorexic patients

We used a sensitive whole body counter which measures potassium-40 (40K) to determine total body potassium and to estimate body cell mass (BCM) in 104 previously untreated patients with upper gastrointestinal malignancies, 233 normal volunteers, and 18 patients with anorexia nervosa. BCM was greater in normal males than in females. In both normal males and females, the BCM tended to decrease with age, both as an absolute measure and as a percentage of body weight. Anorexia nervosa patients experienced marked weight loss (30.5%), and had significant depletion of absolute BCM, but exhibited relative sparing of BCM as indicated by a rise in BCM as a percentage of body weight. This may reflect a normal adaptation and predominant fat utilization in chronic malnutrition. The cancer patients, on the other hand, had significant weight loss (12.7% for females, 13.9% for males) and demonstrated a proportional decline in BCM, with no change in BCM as a percentage of body weight. These findings support the contention that, in the cancer-bearing patient, weight loss consists of a significant depletion of both fat and BCM. The challenge to the clinicians caring for cancer patients is repletion of this supremely functional body compartment.     

Change of body composition over an eight year period among Japanese university students

This study examined the change of body composition in Japanese university students. Subjects were university students divided into two groups by sex for two different time periods: 67 males and 46 females for 1986-1987 and 47 males and 64 females for 1994-1995. Body height, weight, and underwater weight were measured to estimate the percentage of body fat. The fat mass index (FMI) was applied after adjusting fat mass and the fat-free mass index (FFMI) applied after adjusting fat-free mass for body physique by dividing (body height)2. The mean body mass index (BMI) increased from 1986-1987 to 1994-1995 in males and decreased in females, although there were no statistical differences between two time periods in both sexes. The FMI indicates that in 1994-1995 males had significantly more fat adjusted for body height than in 1987. Females in 1994-1995 had significantly less FFMI than those in 1986 despite FMI similar to that of 1986. Our results thus warn against a trend toward excessive thinness in collegiate females and insufficiency of evaluating body composition using the BMI alone.     

Gonadectomy and high dietary fat but not high dietary carbohydrate induce gains in body weight and fat of domestic cats

A high concentration of dietary carbohydrate is suggested to increase the risk of obesity and diabetes mellitus in domestic cats. To evaluate this, food intake, body weight, fat mass and circulating adiposity-related factors were determined in twenty-four sexually mature (9-12 months) cats assigned to four six-cat dietary groups balanced for body weight and sex. The effect of dietary fat in exchange for carbohydrate at 9, 25, 44 and 64 % of metabolisable energy (ME) in a purified diet of constant protein:ME ratio was studied 13 weeks before and 17 weeks after gonadectomy (GX). Body weight did not significantly change among the cats before GX except for an increase of 17 (sem 5) % in cats given the highest-fat diet. Following GX, all groups gained body weight, and body fat mass was positively correlated (r 0.50; P < 0.04) with dietary fat percentage. Post-GX weight gains were much greater for females (+39 (sem 5) %) than males (+10 (sem 4) %). Plasma ghrelin concentration negatively correlated (P < 0.02) with dietary fat percentage and, before GX, was greater (P < 0.05) in females than males. Plasma insulin concentration increased with weight gain induced by high dietary fat. Plasma glucose, TAG and leptin concentrations were not affected by dietary fat percentage, GX or weight gain. These data provide evidence that in cats, high dietary fat, but not carbohydrate, induces weight gain and a congruent increase in insulin, while GX increases sensitivity to weight gain induced by dietary fat.     

Dietary lipids and the low blood cholesterol-cancer association.

The role of dietary fat and cholesterol in the low blood cholesterol-cancer association was examined in the National Health and Nutrition Survey Epidemiologic Follow-up Study (NHEFS) conducted during 1971-1984. Of the 9,593 male and female participants, aged 25-74 years, 638 developed cancer during the median of 10.2 years of follow-up. Diet was assessed using a 24-hour dietary recall. Despite an inverse association between serum cholesterol and cancer, male cases consumed, on average, more dietary cholesterol, a larger proportion of calories as saturated fat, but a similar proportion of calories as linoleic acid. Among females, cases consumed less fat and cholesterol than noncases. Among males with central adiposity (subscapular-to-triceps skinfold ratio greater than or equal to 1), cases ate more dietary cholesterol both absolutely and as a proportion of calories. Among males with peripheral adiposity, cases tended to eat less dietary cholesterol than noncases. Among females, serum cholesterol was inversely associated with cancer risk among those with central adiposity but directly associated among those with peripheral adiposity. Dietary comparisons were adjusted for age, race, body mass index, smoking status, alcohol consumption, education, and economic status. The results indicate that diet cannot explain the low blood cholesterol-cancer association in men. Furthermore, inconsistencies in the literature in this area may be due, in part, to differing proportions of central adiposity in study populations.     

Underreporting of energy intake in an elderly German population.

OBJECTIVES: Within the longitudinal study on nutrition and health status in an aging population in Giessen, Germany (GISELA), the underreporters of energy intake (EI) were identified and characterized. METHODS: EI was assessed in 238 female and 105 male participants of the GISELA study (age range = 60-89 y) by means of a 3-day estimated dietary record developed especially for this study. Resting metabolic rate (RMR) was measured by indirect calorimetry after an overnight fast. EI was expressed as a multiple of RMR and subjects with an EI:RMR ratio below 1.073 were classified as underreporters. RESULTS: Mean EI:RMR was 1.62 +/- 0.46 in females and 1.53 +/- 0.46 in males; 7.6% of the females and 16.2% of the males were identified as underreporters. They showed lower levels of education and significantly greater body weight, body mass index, and fat mass than the adequate reporters. Further, underreporters stated more often than adequate reporters that they want to lose weight. Except for beta-carotene in males, reported nutrient intakes were significantly lower in underreporters than in adequate reporters. Carbohydrate and fat intake in both sexes, protein intake in females calculated as a percentage of EI, and vitamin and mineral densities were not affected by underreporting. CONCLUSIONS: The results indicate that underreporting of EI is related to a low educational level and greater body weight, body mass index, and fat mass and affects all nutrients. These findings should be considered when the association between nutrition and health status is investigated in the elderly.     

Adolescent eating in the absence of hunger and relation to discretionary calorie allowance

Eating in the absence of hunger is a risk factor for overeating during childhood. The objective of this study was to examine eating in the absence of hunger in adolescents based on their familial predisposition to obesity and current weight status. Thirty-one subjects (16 male, 15 female), who were 13 years of age and born at low risk or high risk for obesity, consumed lunch to fullness. After lunch, subjects had access to different snacks for 15 minutes. Eating in the absence of hunger referred to energy intake from the snacks. Low-risk females consumed two and a half times more calories from snacks than high-risk females and twice as many calories as low-risk and high-risk males when expressed as an individualized percentage of daily allowance for discretionary calories. Normal-weight females consumed two and a half times more calories from snacks than obese females and normal-weight males. The association between eating in the absence of hunger and weight and obesity risk status depended on adolescents' sex and could reflect emerging developmental differences, such as dieting or social desirability.     

Total body potassium in aging humans: a longitudinal study

Total body potassium (TBK) data calculated from longitudinal measurements over 18 y of 40K by whole-body counting of 564 male and 61 female healthy humans in a 2-pi liquid scintillation counter show little change in females younger than 50 y compared with males of those ages. Males show less TBK from 41 y onward as they age, with most rapid rate of loss between 41 and 60 y. Females have a rapid loss of TBK when they are older than 60 y; the loss is at a greater rate than that of males. Percent total body fat calculated from total body weight and lean body mass (LBM) derived from TBK document greater adiposity in females at all ages except ages 51-60 y when females are similar to males in change in percent fat per year per centimeter.     

The effects of varying dietary fat on performance and metabolism in trained male and female runners

OBJECTIVES: Low dietary fat intake has become the diet of choice for many athletes. Recent studies in animals and humans suggest that a high fat diet may increase VO2max and endurance. We studied the effects of a low, medium and high fat diet on performance and metabolism in runners. METHODS: Twelve male and 13 female runners (42 miles/week) ate diets of 16% and 31% fat for four weeks. Six males and six females increased their fat intakes to 44%. All diets were designed to be isocaloric. Endurance and VO2max were tested at the end of each diet. Plasma levels of lactate, pyruvate, glucose, glycerol, and triglycerides were measured before and after the VO2max and endurance runs. Free fatty acids were measured during the VO2max and endurance runs. RESULTS: Runners on the low fat diet ate 19% fewer calories than on the medium or high fat diets. Body weight, percent body fat (males=71 kg and 16%; females=57 kg and 19%), VO2max and anaerobic power were not affected by the level of dietary fat. Endurance time increased from the low fat to medium fat diet by 14%. No differences were seen in plasma lactate, glucose, glycerol, triglycerides and fatty acids when comparing the low versus the medium fat diet. Subjects who increased dietary fat to 44% had higher plasma pyruvate (46%) and lower lactate levels (39%) after the endurance run. CONCLUSION: These results suggest that runners on a low fat diet consume fewer calories and have reduced endurance performance than on a medium or high fat diet. A high fat diet, providing sufficient total calories, does not compromise anaerobic power.     

Effect of palatable diet on growth, caloric intake and endocrine-metabolic profile in weanling rats with dorsomedial hypothalamic lesions

Weanling male Sprague-Dawley rats received bilateral electrolytic lesions in the dorsomedial hypothalamic nuclei (DMNL rats); sham-operated rats served as controls. All animals were fed lab chow for 15 postoperative days. At that time they were subdivided into two groups each. One DMNL and one control group continued to be fed lab chow until the termination of the experiment on postoperative day 116. A second DMNL and control group were fed a high-fat diet and 32% sucrose solution (HF/SS diet). All DMNL rats showed reduced body weight and linear growth, but the HF/SS diet depressed these parameters further below the levels of the chow-fed groups. Both DMNL and control rats fed HF/SS had more carcass fat, heavier epididymal fat pads, more carcass fat per calories eaten, higher plasma levels of glucose, glycerol and free fatty acids but lower insulin levels than chow-fed DMNL rats and controls. This occurred in the face of lower body weights and caloric intake. Neither growth hormone nor insulin showed lesion effects. Rats with DMNL exhibited the same inverse relationship between plasma insulin and free fatty acids as controls. The data indicate that DMNL rats respond to the HF/SS diet essentially like sham-operated controls, i.e., they develop dietary obesity. Although they do show some small deficits, their lipogenic capacity is actually significantly greater than that of HF/SS-diet fed controls.     

Energy utilization in food-restricted female rats

We studied changes in energy utilization in mature female rats exposed to varying degrees of food restriction. Food-restricted rats showed considerable energy conservation, exhibited primarily as a reduction in the energy required for daily maintenance. When a given body weight loss was produced by starvation (3 or 6 d), changes in body composition and energy utilization differed only slightly (and temporarily) compared with the same body weight lost by partial food restriction. All food-restricted groups demonstrated a remarkable ability to reduce maintenance energy costs and to achieve zero energy balance at food intakes 40-50% of controls. By contrasting these results with our previous work in food-restricted male rats, we identified possible gender differences in the response to food restriction. Females appear to preserve lean mass to a greater degree than male rats by utilizing relatively more fat for energy needs. This preference for fat as a fuel during negative energy balance suggests that females would lose less body weight for a given reduction in carcass energy than males, since fat is calorically denser than lean mass.     

Race- and sex-specific reference data for triceps and subscapular skinfolds and weight/stature

The best clinical indicators of percentage body fat on statistical grounds are triceps skinfold thickness in females aged 6 to 50.0 yr and boys 6 to 8 yr, and weight/stature 2 (W/S2) in men. The most valid simple clinical estimators of total body fat are W/S2 in females aged 6 to 50.9 yr and adult males 19 yr and older, and subscapular skinfold thickness in boys 6 to 18 yr. This report presents race- and sex-specific reference data for these three measures based on the First Health and Nutrition Examination Survey for individuals 6 to 50.9 yr of age. Data for Blacks and whites are presented separately because of the large differences in their distributions on these measures. When compared to data from the Health Examination Survey, 1960 to 1962, the present data show evidence of a secular trend toward higher values for triceps and subscapular skinfold thickness in the upper percentiles in adults. The tables presented can be used clinically, with the specified reservations to indicate percentage body fat or total body fat for individuals.     

广西在校大学生身体脂肪参数对肺功能的影响

探究广西在校大学生的身体脂肪参数对肺功能的影响,为改善大学生身体功能素质提供依据.方法 随机抽取广西医科大学2 462名(男生716名,女生1 746名)在校大学生为研究对象,并采用奥美体成分测量仪(Tanita MC-180)测量身体脂肪参数,参照国家体质健康测试标准统一测试大学生的身高、体重及肺活量.采用SPSS 20.0软件对数据进行分析.结果 男女大学生的肺活量均随着体脂率的增加呈上升趋势,肺活量体重指数均随着体脂率的增加呈下降趋势(F值分别为41.627,69.196,P值均<0.05).体脂率过低组男大学生肺活量体重指数与身体各部位脂肪参数的相关均无统计学意义(P值均>0.05),体脂率过高组和标准组的肺活量体重指数与不同部位的脂肪参数呈不同程度的负相关性(r值均<0,P值均<0.05).在女大学生中,仅有体脂率过低组和标准组的肺活量体重指数与身体各部位脂肪参数呈负相关(r值均<0,P值均<0.05),体脂率过高组的肺活量体重指数与身体各部位脂肪参数的相关均无统计学意义(P值均>0.05).结论 大学生部分身体脂肪参数可导致一定程度的肺活量体重指数下降,对大学生的肺功能造成一定影响.保持身体各部位适宜的脂肪含量对改善大学生的身体健康和肺功能有一定积极作用.     

Treatment of obese female and male SHHF/Mcc-fa(cp) rats with antihypertensive drugs, nifedipine and enalapril: effects on body weight, fat distribution, insulin resistance and systolic pressure

Little is known about the effects of common antihypertensive drugs in obese, insulin-resistant females. Nine-month-old obese female SHHF/Mcc-fa(cp) rats that received either nifedipine, a calcium channel antagonist, or enalapril, an angiotensin-converting-enzyme inhibitor, for three months were compared with untreated SHHF/Mcc-fa(cp) rats (controls). After one month, nifedipine significantly decreased body weight in obese females compared to either enalapril or controls. After three months of treatment, total, abdominal, and subcutaneous fat masses were decreased in obese females given nifedipine compared to either enalapril or controls. Enalapril treatment was associated with a redistribution of fat mass from abdominal to subcutaneous depots. Nifedipine reduced plasma triglyceride and fasting glucose levels and improved insulin response to an oral glucose load in obese females, whereas enalapril did not appear to affect glycemic control. Systolic pressure was not significantly decreased until after two months of treatment with nifedipine or three months of treatment with enalapril in obese females and may have coincided with improvement in insulin-resistance. Similarly, plasma atrial natriuretic peptide concentrations were significantly lower in obese females given nifedipine. To determine how obese males responded to a calcium channel antagonist, six-month-old obese male SHHF/Mcc-fa(cp) rats were treated for three months with either nifedipine or placebo (controls). Nifedipine-treated obese males showed a mild but significant decrease in weight gain that was due to a decrease in fat deposition in both subcutaneous and abdominal depots and systolic blood pressure was significantly reduced after one month of treatment. Nifedipine did not affect other plasma biochemical parameters in obese males. In conclusion, nifedipine improved systolic pressure and glycemic control in obese female SHHF/Mcc-fa(cp) rats, effects that may be associated with a marked loss in body weight and fat mass and improved lipid metabolism. Nifedipine-treated obese males exhibited only a diminished weight gain that was not associated with changes in diabetic characteristics.     

Body fat distribution and energy metabolism in obese men and women.

Upper body obesity seems to be associated with a better prognosis for weight loss than does lower body obesity. However, the impact of body fat distribution on energy metabolism is not clear.

One hundred fifteen non-diabetic obese Caucasians (64 males and 51 females) and 108 Caucasian lean controls (82 males and 26 females) were studied.

Body composition was assessed by hydrodensitometry and body fat distribution was estimated by the waist-to-thigh circumference ratio (W/T). Values of 24-hour energy expenditure (24h-EE), basal metabolic rate (BMR), sleeping metabolic rate (SMR) and respiratory quotient (RQ) were measured in a respiration chamber.

BMR, adjusted for differences in fat-free mass, fat mass, age and sex, correlated with W/T in obese males (r = 0.40; p < 0.01), but not in obese females. Obese male subjects with upper body obesity had BMR significantly higher than those with lower body obesity (2189 +/? 268 vs 1974 +/? 141 kcal/day; p < 0.01), independently of differences in fat-free mass, fat mass and age. No correlations were found between W/T and adjusted 24h-EE, SMR or RQ in all examined groups.

These findings indicate that in obese males, upper body obesity is associated with increased metabolic rate, possibly related to higher levels of lipid turnover in visceral fat.     

Food consumption, habitual physical activity, and body fatness in young Dutch adults

The relationship between body fatness and both food consumption and habitual physical activity, was studied in young adult males (n = 122) and females (n = 140) in three age groups (20 to 22, 25 to 27, and 30 to 32 yr) in a Dutch population. In males the average daily energy intake was rather high (about 3000 kcal) and average body weight increased by 1.2 kg in the preceding year. Both findings suggest the existence of a positive energy balance. In females the average daily energy intake was normal (about 2170 kcal) and average body weight remained constant. Physical activity at work and sport was not related to the percentage of body fat in either sex, but physical activity, such as walking and cycling during leisure time, was slightly lower in fatter males. The fatter subjects tended to eat less than the leaner subjects but this was only significant in females. However, after adjusting for lean body mass and physical activity in a multiple regression model, energy intake was inversely related to percentage of body fat in both sexes. Change in body weight in the period of 4 months preceding the food consumption study seemed to reflect energy balance at the time of the food consumption study in only leaner and fatter females. After adjusting also for change in body weight in these females energy intake of fatter females remained lower, suggesting a reduced need for energy among many fatter females.     

Prediction of body fat by anthropometry in older Chinese people

OBJECTIVE: To derive regression equations for fat percentage by using simple anthropometric measurements applicable in normal and immobile (cannot stand or walk) older people. RESEARCH METHODS AND PROCEDURES: The study population comprised 352 females and 261 males, apparently well and community-dwelling, aged 69 to 82 years. Fifty-one females and 27 males were recruited for external validation. Body weight, standing height, arm span, triceps and biceps skinfold thicknesses (SFTs), and midarm circumference were measured. The reference method of total body fat percentage was dual-energy X-ray densitometry. Predictive equations for fat percentages were derived by stepwise multiple linear regression on anthropometric indices and gender. RESULTS: Upper-limb SFTs, body mass index, and gender yielded the more predictive equation. The SEE was 4.1% weight. There was a significant trend of underestimation in overweight subjects, especially in females. The equation using SFTs and midarm circumference was less reliable but more applicable to older immobile people and those with significant kyphoscoliosis. CONCLUSIONS: The combination of body mass index and upper-limb SFTs gives reliable prediction of fat percentages in older Chinese people, except in the obese.     

Calories, fat and cholesterol: intake patterns in the US population by race, sex and age.

Nutrient intakes were investigated for Blacks and Whites using data from the NHANES II survey (1976-80). Intake of energy, total fat, saturated fat, dietary cholesterol, P/S ratio, and per cent of calories derived from total and saturated fat are examined by sex and age, both in absolute terms and per unit of body weight. For most age and sex categories, Blacks are found to have a lower intake of energy and fats than Whites; however, Blacks have a consistently higher intake of dietary cholesterol. The ratio of polyunsaturated fats to saturated fats is higher in females than in males, but all age-sex groups are substantially below recommended levels. Per cent of calories from total and saturated fat are similar in most age-sex groups. Possible explanations of the observed patterns include activity level and metabolic differences.     

减肥运动处方对超重肥胖大学生体脂、血糖与抵抗素的影响

目的探讨减肥运动处方对超重肥胖大学生的体脂、血糖与抵抗素影响。方法研究对象为单纯性超重肥胖的大一、大二学生,男性9人,女性13人,对其进行身体形态与机能检查、运动能力测试后确定功能能力(FC),根据不同对象确定减肥目标、运动项目,运动强度定为FC的60%～70%及RPE在13～15级,每次运动时间为60min,运动频率为5次/周,8周后测定相关指标。结果通过8周减肥运动处方的实施,实验前后超重肥胖的男、女大学生的体重、BMI、WHR、体脂%、体表面积等相关肥胖指标显著下降(P<0.01);实验前后的体脂重量、血糖显著降低(P<0.01);实验前后血抵抗素男性显著下降(P<0.01)、女性有所下降(P<0.05),通过Bivariate Correlation进行Pearson Correlation相关性分析,男性血抵抗素与BMI、腰臀比相关(P<0.05),女性无相关性。结论该减肥运动处方安全、有效,在无饮食控制下实施8周能有效改善体重、BMI、体脂%、脂肪重量、WHR、体表面积及身体密度,取得较好的减肥效果,能降低血糖和血抵抗素水平。     

Quantification of body fat distribution in the abdomen using computed tomography

A computed tomographic method was used to assess the pattern of abdominal fat distribution in normal males and females at different abdominal levels. The method permitted site specific calculations of total body volume (TA), total fat volume (TF), subcutaneous fat volume (SF), and intraabdominal fat volume (IF) in each computed tomography scan. The ratio of TF/TA, SF/TF and IF/TF were calculated for the L1, L3, and L5 vertebral levels. Regression analysis of IF versus SF, SF versus TF, IF versus TF, TF versus TA, and TF versus body mass index and age were calculated. A significant linear correlation between the measured variables TA, SF, IF, and TF and between TF and body mass index was found for virtually all correlations attempted at all scanned levels. Females had a higher total fat volume and greater percentage of subcutaneous fat at all levels. Males accumulated more fat intraabdominally than subcutaneously at the L1 and L3 levels. The male-female differences were greatest at L1 and the ratio SF/IF statistically significant at the L1 and L5 levels. Our results demonstrate that computed tomography can noninvasively quantify abdominal fat distribution at various sites. There is an inherent difference in abdominal fat distribution between males and females that is not related to weight. The distribution of body fat in males and females varies markedly from level to level.