Seasonal Changes in Midlife Women'S Percentage Body Fat: A 1-Year Cohort Study.

Objective: The purpose of this longitudinal, observational study was to examine whether age and seasonal changes in sedentary activity (sedAct), moderate-to-vigorous physical activity (MVPA), and energy intake (EI) predict changes in body composition among midlife women. We hypothesized that reductions in MVPA and increases in sedAct and EI in winter, along with greater baseline age would predict increases in percentage body fat (%BF) across seasons. Design: This study used a longitudinal, within-subjects design. Setting: This study took place in Grand Forks, North Dakota. Participants: Participants included 52 midlife women (aged 40-60 years) who were observed over the course of one year. Measurements: Percentage body fat measures were obtained via whole body Dual Energy X-ray absorptiometry. Participants were scanned once per season. We measured EI using the ASA24®. We used a GTX3 accelerometer to measure physical activity. Each season, participants wore the monitors for 7 days, 12 hours per day. All measures began in summer. Results: Results of hierarchical multiple regression (MR) analyses showed that age increases (ß = 0.310, p = 0.021) and summer-to-fall increases in EI (ß = 0.427, p = 0.002) predicted seasonal increases in %BF (R2 = .36, F(5, 42)= 4.66, p = 0.02). Changes in MVPA and sedAct were not significant predictors. Repeated measures ANCOVA revealed that summer (M = 37.7263, 95% CI [35.8377, 39.6149]) to winter (M = 38.1463, 95% CI [36.1983, 40.0942]) increases in %BF are not reversed by spring (M = 37.8761, 95% CI [35.9365, 39.8157]). Conclusions: To minimize increases in %BF and maintain health, midlife women, particularly older women, should be encouraged to pay extra attention to their diet in the fall months.

Obesity, diet, and poverty: trends in the Russian transition to market economy.

OBJECTIVE: To examine trends in macronutrient intake, overweight, and obesity. DESIGN: Cross-sectional samples-collected nine times between 1992 and 2000-from the Russian Longitudinal Monitoring Survey provide interviewer-administered 24-h diet recalls and measured height and weight, together with detailed information regarding income and expenditures. SETTING: The Russian Federation. SUBJECTS: Women and men, aged 19-55 y. INTERVENTIONS: None. METHODS: A nationally representative sample of working-age Russian adults was stratified by gender and income (per cent of regional poverty level). Secular trends in mean energy and macronutrient intake, as well as prevalence of overweight and obesity in the population are described over the first 8 y of the Russian Federation. RESULTS: Overall, energy intake increased slightly. Fat, as a percentage of energy (E%), decreased from 39.6 to 31.6% and protein, as a per cent of energy, decreased from 14.3 to 12.5%. Overweight (determined by body mass index (BMI) >/=25 kg/m(2)) prevalence remained relatively stable at about 50% and obesity (BMI >/=30 kg/m(2)) prevalence increased from 13.3 to 16.0% of the adult population. Women consumed less energy than men and displayed higher prevalences of overweight and obesity in all time periods. There was an income effect among men in all time periods, with higher-income men consuming more calories, fat, and protein than lower-income men; this effect was not apparent in women except in the proportion of fat and protein intake. CONCLUSIONS: The adult Russian population appears to have escaped macronutrient privation during economic reform and has experienced increasing rates of obesity.

The increasing prevalence of snacking among US children from 1977 to 1996.

OBJECTIVES: To determine snacking trends and changes in nutrient contribution of snacking over time. STUDY DESIGN: Nationally representative data from the 1977-78 Nationwide Food Consumption Survey (NFCS77), 1989-91 Continuing Survey of Food Intake by Individuals (CSFII89), and 1994-96 (CSFII96) were used. The sample consisted of 21,236 individuals aged 2 to 18 years. METHODS: For each survey year, mean numbers of snacks consumed, mean grams consumed per snack, and mean energy intake from snacks were computed, as was contribution of snacking to total energy intake and fat intake. Snacking was self-defined, and a snacking occasion consisted of all snack foods consumed during a 15-minute period. Differences in means between age groups and across survey years were compared. RESULTS: The prevalence of snacking increased in all age groups. The average size of snacks and energy per snack remained relatively constant; however, the number of snacking occasions increased significantly, therefore increasing the average daily energy from snacks. Compared with non-snack eating occasions, the nutrient contribution of snacks decreased in calcium density and increased in energy density and proportion of energy from fat. CONCLUSION: Snacking is extremely prevalent in our society. Healthy snack food choices should be emphasized over high-energy density convenience snacks for children.

Where's the fat? Trends in U.S. diets 1965-1996.

BACKGROUND: Controlling fat intake has been an ongoing health concern since the late 1950s. This study examines 30-year trends in food sources of fat intake. It focuses on both total fat and specific fatty acid classes to ascertain if there are trend differences by age, sex, or race/ethnicity. METHODS: Nationally representative cross-sectional U.S. Department of Agriculture surveys from 1965, 1977-1978, 1989-1991, and 1994-1996 form the basis of this analysis, which compares 45,357 adults aged 18 years and older. Food files linked over time are used to create comparable food groups and nutrient values. RESULTS: The proportion of fat in the diet from grain-based mixed dishes, higher-fat snack foods, and higher fat potatoes has increased to partially offset reductions in fat from dairy, red meat, and added fat categories. Food sources of fat differ by race/ethnicity and age. The percentage of fat from fast foods and ethnic foods increased over time from 1 to 11% of total fat. The ratio of visible to invisible fat declined considerably. CONCLUSION: While animal product-based sources of fat continue to require emphasis, the shift toward fast foods, fried foods, and grain-based mixed dish and edible oil sources requires more focus.