Dietary variety within food groups: association with energy intake and body fatness in men and women.
BACKGROUND: Short-term experimental studies suggest that dietary variety may influence body fatness but no long-term human studies have been reported. OBJECTIVE: The purpose of this study was to determine whether dietary variety within food groups influences energy intake and body fatness. DESIGN: Seventy-one healthy men and women (aged 20-80 y), who provided accurate reports of dietary intake and completed a body-composition assessment, were studied. RESULTS: Dietary variety was positively associated with energy intake within each of 10 food groups (r = 0.27-0.56, P < 0.05). In multiple regression analysis with age and sex controlled for, dietary variety of sweets, snacks, condiments, entrees, and carbohydrates (as a group) was positively associated with body fatness (partial r = 0.38, P = 0.001) whereas variety from vegetables was negatively associated (partial r = -0.31, P = 0.01) (R2 = 0.46, P < 0.0001). In separate models, both a variety ratio (variety of vegetables/variety of sweets, snacks, condiments, entrees, and carbohydrates) and percentage dietary fat were significant predictors of body fatness (controlled for age and sex, partial r = -0.39 and 0.31, respectively, P < 0.01). However, dietary fat was no longer significantly associated with body fatness when the variety ratio and dietary fat were included in the same model. CONCLUSIONS: Our data, coupled with those of previous short-term studies, suggest that a high variety of sweets, snacks, condiments, entrees, and carbohydrates coupled with a low variety of vegetables promotes long-term increases in energy intake and body fatness. These findings may help explain the rising prevalence of obesity. (+info)
Association of dietary protein intake and coffee consumption with serum homocysteine concentrations in an older population.
BACKGROUND: Elevated blood concentrations of total homocysteine (tHcy) have been implicated in the pathogenesis of atherosclerotic cardiovascular disease. Previous studies identified suboptimal nutritional status and dietary intake of folate, vitamin B-6, and vitamin B-12 as determinants of elevated tHcy. OBJECTIVE: We identified other nutritional factors associated with tHcy in 260 retired schoolteachers in the Baltimore metropolitan area. DESIGN: We performed observational analyses of baseline and 2-4-mo follow-up data collected in a study designed to test the feasibility of conducting a large-scale clinical trial of vitamin supplements by mail. The study population consisted of 151 women and 109 men with a median age of 64 y. At baseline, each participant completed a food-frequency questionnaire. At follow-up, fasting serum tHcy was measured. RESULTS: In multivariable linear regression and generalized linear models, there was an independent, inverse dose-response relation between dietary protein and In tHcy (P = 0.002) and a positive, significant dose-response relation between coffee consumption and In tHcy (P for trend = 0.01). Other significant predictors of In tHcy were creatinine (positive; P = 0.0001) and prestudy use of supplemental B vitamins (inverse; P = 0.03). In stratified analyses restricted to persons receiving standard multivitamin therapy, the association of 1n tHcy with dietary protein and coffee persisted. CONCLUSIONS: These results support the hypothesis that increased protein intake and decreased coffee consumption may reduce tHcy and potentially prevent atherosclerotic cardiovascular disease and other disease outcomes. (+info)
Underreporting of habitual food intake is explained by undereating in highly motivated lean women.
Underreporting of habitual food intake can be explained by underrecording and/or undereating. This study was designed to discriminate between the two errors mentioned, by measuring energy and water balance. Twenty-four lean female dieticians were recruited as subjects. Energy intake and water intake were measured for 1 wk with a weighed dietary record. Energy expenditure was estimated from measurements of resting metabolic rate, and measured physical activity with a triaxial accelerometer for movement registration. Water loss was estimated with deuterium-labeled water. Energy balance was determined by measuring the change in body mass over a nonrecording week (preceding the recording week) and over the recording week. Mean energy and water intake were 8.5 +/- 1.0 MJ/d and 2.3 +/- 0.5 L/d. The change in body mass in the nonrecording week was 0.1 +/- 0.6 kg and in the recording week -0.6 +/- 0.8 kg (paired t test; P = 0.02), indicating 16% undereating. Recorded water intake plus calculated metabolic water closely matched measured water loss (r = 0.93; P = 0.0001), which indicated a high recording precision. In conclusion, in the studied group of highly motivated lean women, there was 16% underreporting of habitual food intake, which could be explained by undereating. (+info)
Multicenter randomized trial of a comprehensive prepared meal program in type 2 diabetes.
OBJECTIVE: To evaluate the clinical effects of a comprehensive prepackaged meal plan, incorporating the overall dietary guidelines of the American Diabetes Association and other national health organizations, relative to those of a self-selected diet based on exchange lists in free-living individuals with type 2 diabetes. RESEARCH DESIGN AND METHODS: A total of 202 women and men (BMI < or = 42 kg/m2) whose diabetes was treated with diet alone or an oral hypoglycemic agent were enrolled at 10 medical centers. After a 4-week baseline period, participants were randomized to a nutrient-fortified prepared meal plan or a self-selected exchange-list diet for 10 weeks. On a caloric basis, both interventions were designed to provide 55-60% carbohydrate, 20-30% fat, and 15-20% protein. At intervals, 3-day food records were completed, and body weight, glycemic control, plasma lipids, and blood pressure were assessed. RESULTS: Food records showed that multiple nutritional improvements were achieved with both diet plans. There were significant overall reductions in body weight and BMI, fasting plasma glucose and serum insulin, fructosamine, HbA1c, total and LDL cholesterol, and blood pressure (P < 0.001 or better for all). In general, differences in major end points between the diet plans were not statistically significant. CONCLUSIONS: Glycemic control and cardiovascular risk factors improve in individuals with type 2 diabetes who consume diets in accordance with the American Diabetes Association guidelines. The prepared meal program was as clinically effective as the exchange-list diet. The prepared meal plan has the additional advantages of being easily prescribed and eliminating the complexities of meeting the multiple dietary recommendations for type 2 diabetes management. (+info)
Diabetes risk factors in low-income Mexican-American children.
OBJECTIVE: To learn if Mexican-American children from low income neighborhoods have excess diabetes risk factors. RESEARCH DESIGN AND METHODS: The study involved 173 Mexican-American children aged 9 years. This is the age before type 2 diabetes usually develops in youths and where the disparity in body fat between Mexican-American and non-Hispanic white children is evident. The study also targets poor children because diabetes and being overweight are more common in Mexican-American adults from a lower than from a higher socioeconomic status. The diabetes risk factors measured were percent body fat, dietary fat intake, daily fruit and vegetable intake, and physical fitness. Body fat was measured by bioelectric impedance, dietary intake was measured by three 24-h dietary recalls, and physical fitness was measured by a modified Harvard step test. RESULTS: According to self-reported dietary recalls, Mexican-American children ate higher than recommended fat servings and had higher percent energy from fat and saturated fat. On the other hand, their reported daily fruit and vegetable intake was half of that recommended by national dietary guidelines. A large percentage of these children were at unacceptable physical fitness levels. Percent body fat was higher in these Mexican-American children than that reported for non-Hispanic white children. Finally, 60% of the children had a first- or second-degree relative with diabetes. CONCLUSIONS: Because diabetes is highly prevalent in Mexican-American adults, type 2 diabetes in increasing in Mexican-American youths, and diabetes risk factors are more common in Mexican-American children, a prudent measure would be to explore early-age diabetes risk factor prevention programs in this population. (+info)
Foods contributing to absolute intake and variance in intake of fat, fatty acids and cholesterol in middle-aged Japanese.
On the basis of 351 one-day weighed diet records, we selected foods/recipes contributing to nutrients of interest for a data-based food frequency questionnaire by contribution analysis and multiple regression analysis. Total fat was largely of animal and vegetable origin, irrespective of analytic methods. Saturated fatty acid was mostly from animal and vegetable sources according to contribution analysis, and that of animal origin was the main contributor by multiple regression analysis. Mono-unsaturated fatty acid was substantially supplied by animal and vegetable products by either analytic method. Poly-unsaturated fatty acid, n-6 poly-unsaturated fatty acid and linoleic acid were found to be of vegetable origin and chicken egg according to contribution analysis; while vegetable oil and mayonnaise were the major contributors to variance in intake. Arachidonic acid was, however, mostly provided by animal sources including chicken egg and fish, irrespective of analytic methods. N-3 poly-unsaturated fatty acids and alpha-linolenic acid were of vegetable and marine origin. Eicosapentaenoic and docosahexaenoic acids were particularly from marine products, irrespective of analytic methods, except for chicken egg in docosahexaenoic acid by contribution analysis. Cholesterol was of animal and marine origin by either analytic method. Thus, foods contributing to absolute intake and variance in intake of fat, fatty acids and cholesterol differed considerably. (+info)
Food preferences and reported frequencies of food consumption as predictors of current diet in young women.
BACKGROUND: Self-reported food preferences and frequencies of food consumption have served as proxy measures of the current diet in consumer research and in nutritional epidemiology studies, respectively. OBJECTIVE: The objective was to determine whether food preferences and food-frequency scores are associated variables that are predictive of nutrient intakes. DESIGN: College-age women (n = 87) completed a 98-item food-frequency questionnaire and rated preferences for many of the same foods on a 9-point category scale. Estimated intakes of fat, fiber, and vitamin C were obtained by using 3-d food records. RESULTS: For virtually all item pairs tested, food preferences and reported frequencies of consumption of the same foods were significantly correlated with each other. The median Pearson correlation coefficient was 0.40 (range: -0.04 to 0.62). Correlations improved when foods were aggregated into factor-based food groups. The slope of the relation between food preferences and frequency of consumption varied with food category. Both food preferences and food frequencies predicted dietary outcomes. Fat consumption was predicted equally well by either approach in a multiple regression model. Intakes of fiber and vitamin C were better predicted by food-frequency scores than by stated preferences for vegetables and fruit. CONCLUSIONS: Reported frequencies of food consumption, the core of the food-frequency approach, were associated with food likes and dislikes. Food preferences were a predictor of dietary intakes and may provide an alternative to the food-frequency approach for dietary intake assessment. (+info)
Energy metabolism increases and regional body fat decreases while regional muscle mass is spared in humans climbing Mt. Everest.
The objectives of the study were to determine regional changes in body composition, energy expenditure by means of doubly labeled water, and net energy balance during exposure to high and extreme altitudes (5,300-8,848 m). This study focuses on a subset of subjects who consumed the doubly labeled water (three base camp personnel and seven climbers). Regional body composition was determined by measuring skinfold thicknesses and circumferences at 10 different sites on the body. Energy expenditure was measured by doubly labeled water excretion. Discrepancies between actual energy expenditure and data obtained from diet records and body weight changes suggested a chronic underreporting of dietary energy intake, especially by those subjects who reached the highest altitudes. This underreporting may be due in part to diminished cognition or to a preferential focus on survival, rather than on filling out diet records accurately. Mean adjusted dietary intakes were 10.50 +/- 0. 65 MJ/d (2510 +/- 155 kcal/d) for those who remained at base camp, and 20.63 +/- 6.56 MJ/d (4931 +/- 1568 kcal/d) for those who climbed above base camp. Energy expenditure averaged 2.5-3.0 times sea level resting energy expenditure. Differential changes in regional body composition suggested a preferential loss of fat mass and a relative sparing of muscle mass, despite insufficient energy intake to maintain body weight. (+info)