Few experimental data are available to support the notion that reducing night-time eating changes total daily energy intake (EI) or body weight in healthy adults. The present study primarily examined the short-term effect of night eating restriction (NER) on daily EI in healthy young men. It secondarily examined body weight and moods associated with NER. Using a cross-over design, twenty-nine men (20·9 (sd 2·5) years; 24·4 (sd 2·5) kg/m2) initiated a 2-week NER intervention (elimination of EI from 19.00 to 06.00 hours) and a 2-week control condition, counterbalanced and separated by a 1-week washout period. EI and macronutrient intake were assessed using computerised, multiple-pass 24 h food recalls, body weight via a digital scale and mood using the Profile of Mood States survey. Of the twenty-nine participants, twenty-seven (93 %) completed all aspects of the study. During the NER condition, the participants consumed less total energy per d than during the control condition (10 125 v. 11 146 kJ/d; F= 6·41; P= 0·018). During the NER condition, no energy was reported consumed between 19.00 and 06.00 hours; however, during the control condition, the energy intake of participants was 2920 (sd 1347) kJ/d between 19.00 and 06.00 hours. There was a significant difference in weight change between the NER ( − 0·4 (sd 1·1) kg) and control (+0·6 (sd 0·9) kg) conditions (F= 22·68; P< 0·001). Differences in total mood score or mood subscales between the NER and control conditions were not apparent (P>0·05). These findings provide support for NER decreasing short-term EI in healthy young men.
1 January 2008 in International Journal of Behavioral Nutrition and Physical Activity
Physical Activity Across the Curriculum (PAAC) is a 3-year elementary school-based intervention to determine if increased amounts of moderate intensity physical activity performed in the classroom will diminish gains in body mass index (BMI). It is a cluster-randomized, controlled trial, involving 4905 children (2505 intervention, 2400 control).
This study aims to expand the evaluation of normal weight obesity (NWO) and its association with insulin resistance using an NHANES (1999–2006) sample of US adults. A cross-sectional study including 5983 men and women (50.8%) was conducted. Body fat percentage (BF%) was assessed using dual-energy X-ray absorptiometry. Expanded normal weight obesity (eNWO) categories, pairings of BMI and body fat percentage classifications, were created using standard cut-points for BMI and sex-specific median for BF%. Homeostatic model assessment-insulin resistance (HOMA-IR) levels were used to index insulin resistance. Mean ± SE values were BMI: 27.9 ± 0.2 (women) and 27.8 ± 0.1 (men); body fat percentage: 40.5 ± 0.2 (women) and 27.8 ± 0.2 (men); and HOMA-IR: 2.04 ± 0.05 (women) and 2.47 ± 0.09 (men). HOMA-IR differed systematically and in a dose-response fashion across all levels of the eNWO categories (,). As BMI levels increased, HOMA-IR increased significantly, and within each BMI category, higher levels of body fat were associated with higher levels of HOMA-IR. Both high BMI and high BF% were strongly related to insulin resistance. Insulin resistance appears to increase incrementally according to BMI levels primarily and body fat levels secondarily. Including a precise measure of body fat with BMI adds little to the utility of BMI in the prediction of insulin resistance.
T college-aged population, a group at high risk for developing obesity, is unknown. Purpose: We aimed to evaluate the effect of 6 months of supervised minimal RT in previously sedentary, overweight (mean ± SEM, BMI = 27.7 ± 0.5 kg·m−2) young adults (21.0 ± 0.5 yr) on 24-h EE, resting metabolic rate (RMR), sleep metabolic rate (SMR), and substrate oxidation using whole-room indirect calorimetry 72 h after the last RT session. Methods: Participants were randomized to RT (one set, 3 d·wk−1, three to six repetition maximums, nine exercises; N = 22) or control (C, N = 17) groups and completed all assessments at baseline and at 6 months. Results: There was a significant (P < 0.05) increase in 24-h EE in the RT (527 ± 220 kJ·d−1) and C (270 ± 168 kJ·d−1) groups; however, the difference between groups was not significant (P = 0.30). Twenty-four hours of fat oxidation (g·d−1) was not altered after RT; however, reductions in RT assessed during both rest (P < 0.05) and sleep (P < 0.05) suggested increased fat oxidation in RT compared with C during these periods. SMR (8.4 ± 8.6%) and RMR (7.4 ± 8.7%) increased significantly in RT (P < 0.001) but not in C, resulting in significant (P < 0.001) between-group differences for SMR with a trend for significant (P = 0.07) between-group differences for RMR. Conclusion: A minimal RT program that required little time to complete (11min per session) resulted in a chronic increase in energy expenditure. This adaptation in energy expenditure may have a favorable impact on energy balance and fat oxidation sufficient to assist with the prevention of obesity in sedentary, overweight young adults, a group at high risk for developing obesity....