The Midwest Exercise Trial for the Prevention of Weight Regain: MET POWeR

Pre-post intervention exploring cognitive function and relationships with weight loss, intervention adherence and dropout

Objective

To evaluate the association between baseline cognitive function, intervention dropout, adherence and 3-month weight loss (WL) when controlling for confounding demographic variables.

Methods

107 (Mage = 40.9 yrs.), BMI in the overweight and obese range (BMI = 35.6 kg/m²), men (N = 17) and women (N = 90) completed a 3-month WL intervention. Participants attended weekly behavioral sessions, comply with a reduced calorie diet, and complete 100 min of physical activity (PA)/wk. Cognitive function tasks at baseline included Flanker (attention), Stroop (executive control) and working memory, demographics, body weight and cardiovascular fitness were assessed at baseline. Session attendance, adherence to PA and diet were recorded weekly.

Results

Baseline attention was positively correlated with age (p < .05), education (p < .05), attendance (p < .05), diet (p < .05) and PA (p < .05). Baseline executive control (p < .05) and working memory (p < .05) were each associated with % WL. Baseline executive control (p < .01) and working memory (p < .001) were also each associated with education. ANOVA indicated that baseline attention (p < .01) was associated with WL, specifically for comparing those who achieved 5-10% WL (p < .01) and those who achieved greater than 10% WL (p < .01) to those who dropped.

Significance

Results suggest that stronger baseline attention is associated with completion of a 3-mo. WL intervention. Executive control and working memory are associated with amount of WL achieved.

NCT registration

US NIH Clinical Trials, NCT01664715.

The impact of exercise and cumulative physical activity on energy intake and diet quality in adults enrolled in the Midwest Exercise Trial for the Prevention of Weight Regain

The purpose of this study was to assess impact of different volumes of exercise as well as cumulative moderate to vigorous physical activity (MVPA) on energy intake (EI) and diet quality, as assessed by the Healthy Eating Index-2010(HEI-2010), across a 12-month weight maintenance intervention. Participants were asked to attend group behavioural sessions, eat a diet designed for weight maintenance and exercise either 150, 225 or 300 min/week. Dietary intake was assessed by 3-d food records, and MVPA was assessed by accelerometry. Two hundred and twenty-four participants (42·5 years of age, 82 % female) provided valid dietary data for at least one time point. There was no evidence of group differences in EI, total HEI-2010 score or any of the HEI-2010 component scores (all P > 0·05). After adjusting for age, sex, time, group and group-by-time interactions, there was an effect of cumulative MVPA on EI (1·08, P = 0·04), total HEI-2010 scores (-0·02, P = 0·003), Na (-0·006, P = 0·002) and empty energy scores (-0·007, P = 0·004. There was evidence of a small relationship between cumulative daily EI and weight (β: 0·00187, 95 % CI 0·001, P = 0·003). However, there was no evidence for a relationship between HEI total score (β: -0·006, 95 % CI 0·07, 0·06) or component scores (all P > 0·05) and change in weight across time. The results of this study suggest that increased cumulative MVPA is associated with clinically insignificant increases in EI and decreases in HEI.

A Randomized Trial Evaluating Exercise for the Prevention of Weight Regain

OBJECTIVE

This study aimed to evaluate the effectiveness of three levels of exercise on weight regain subsequent to clinically meaningful weight loss (WL).

METHODS

Adults with overweight or obesity (n = 298) initiated a 3-month behavioral WL intervention, which included reduced energy intake, increased exercise, and weekly behavioral counseling. Participants achieving ≥5% WL (n = 235) began a 12-month behavioral WL maintenance intervention and were randomized to 150 min/wk (n = 76), 225 min/wk (n = 80), or 300 min/wk (n = 79) of partially supervised moderate-to-vigorous-intensity exercise.

RESULTS

Participants randomized to 150, 225, and 300 minutes of exercise completed 129 ± 30, 153 ± 49 and 179 ± 62 min/wk of exercise (supervised + unsupervised), respectively. Mean WL at 3 months (9.5 ± 3.1 kg) was similar across randomized groups (P = 0.68). Weight change across 12 months was 1.1 ± 6.5 kg, 3.2 ± 5.7 kg, and 2.8 ± 6.9 kg in the 150, 225, and 300 min/wk groups, respectively. Intent-to-treat analysis revealed no significant overall trend across the three treatment groups (P = 0.09), effects for group (P = 0.08), or sex (P = 0.21).

CONCLUSIONS

This study found no evidence for an association between the volume of moderate-to-vigorous-intensity exercise and weight regain across 12 months following clinically relevant WL. Further, results suggest that exercise volumes lower than those currently recommended for WL maintenance, when completed in conjunction with a behavioral weight-maintenance intervention, may minimize weight regain over 12 months.

Modeling interactions between brain function, diet adherence behaviors, and weight loss success

INTRODUCTION

Obesity is linked to altered activation in reward and control brain circuitry; however, the associated brain activity related to successful or unsuccessful weight loss (WL) is unclear.

METHODS

Adults with obesity (N = 75) completed a baseline functional magnetic resonance imaging (fMRI) scan before entering a WL intervention (ie,3-month diet and physical activity [PA] program). We conducted an exploratory analysis to identify the contributions of baseline brain activation, adherence behavior patterns, and the associated connections to WL at the conclusion of a 3-month WL intervention. Food cue-reactivity brain regions were functionally identified using fMRI to index brain activation to food vs nonfood cues. Food consumption, PA, and class attendance were collected weekly during the 3-month intervention.

RESULTS

The left middle frontal gyrus (L-MFG, BA 46) and right middle frontal gyrus (R-MFG; BA 9) were positively activated when viewing food compared with nonfood images. Structural equation modeling with bootstrapping was used to investigate a hypothesized path model and revealed the following significant paths: (1) attendance to 3-month WL, (2) R-MFG to attendance, and (3) indirect effects of R-MFG through attendance on WL.

CONCLUSION

Findings suggest that brain activation to appetitive food cues predicts future WL through mediating session attendance, diet, and PA. This study contributes to the growing evidence of the importance of food cue reactivity and self-regulation brain regions and their impact on WL outcomes.

The impact of supervised weight loss and intentional weight regain on sex hormone binding globulin and testosterone in premenopausal women

What is the impact of intentional weight loss and regain on serum androgens in women? We conducted an ancillary analysis of prospectively collected samples from a randomized controlled trial. The trial involved supervised 10% weight loss (8.5 kg on average) with diet and exercise over 4-6 months followed by supervised intentional regain of 50% of the lost weight (4.6 kg on average) over 4-6 months. Participants were randomized prior to the partial weight regain component to either continuation or cessation of endurance exercise. Analytic sample included 30 obese premenopausal women (mean age of 40 ± 5.9 years, mean baseline body mass index (BMI) of 32.9 ± 4.2 kg/m(2)) with metabolic syndrome. We evaluated sex hormone binding globulin (SHBG), total testosterone (T), free androgen index (FAI), and high molecular weight adiponectin (HMWAdp). Insulin, homeostasis model assessment (HOMA), and quantitative insulin sensitivity check index (QUICKI), and visceral adipose tissue (VAT) measured in the original trial were reanalyzed for the current analytic sample. Insulin, HOMA, and QUICKI improved with weight loss and were maintained despite weight regain. Log-transformed SHBG significantly increased from baseline to weight loss, and then significantly decreased with weight regain. LogFAI and logVAT decreased similarly and increased with weight loss followed by weight regain. No changes were found in logT and LogHMWAdp. There was no significant difference in any tested parameters by exercise between the groups. SHBG showed prominent sensitivity to body mass fluctuations, as reduction with controlled intentional weight regain showed an inverse relationship to VAT and occurred despite stable HMWAdp and sustained improvements with insulin resistance. FAI showed opposite changes to SHBG, while T did not change significantly with weight. Continued exercise during weight regain did not appear to impact these findings.

Physical Activity and Exercise as a Basic Preventive Measure (Primary Prevention, Prevention after Renal Transplantation)

Movement is an inseparable part of one's life, and has been a basic everyday activity through the history of mankind. However, a lack of physical activity and availability of food have resulted in a variety of serious health impairments. The 20th century has witnessed a steep rise of mortality from cardiovascular disease, increase in the prevalence of type-2 diabetes mellitus, malignant diseases, and dramatic increase in body weight initially in industrialized nations followed, in the last two decades of the last century, by the populations of third-world countries with all inherent consequences of this phenomenon. Preventive programmes involving physical activity have also been on the list of top priorities of various materials issued by the World Health Organization. Physical activity is one of the simplest non-pharmacological tools in the prevention of a plethora of diseases. The simplest physical activity, even for therapeutic purposes, is walking. We can walk any time, virtually anywhere, so walking is also the least expensive therapeutic option.