A Pilot Randomized Trial of Oral Magnesium Supplementation on Supraventricular Arrhythmias.

Low magnesium may increase the risk of atrial fibrillation. We conducted a double-blind pilot randomized trial to assess adherence to oral magnesium supplementation (400 mg of magnesium oxide daily) and a matching placebo, estimate the effect on circulating magnesium concentrations, and evaluate the feasibility of using an ambulatory heart rhythm monitoring device (ZioPatch) for assessing premature atrial contractions. A total of 59 participants were randomized; 73% were women, and the mean age was 62 years. A total of 98% of the participants completed the follow-up. In the magnesium supplement group, 75% of pills were taken, and in the placebo group, 83% were taken. The change in magnesium concentrations was significantly greater for those given the magnesium supplements than for those given the placebo (0.07; 95% confidence interval: 0.03, 0.12 mEq/L; p = 0.002). The ZioPatch wear time was approximately 13 of the requested 14 days at baseline and follow-up. There was no difference by intervention assignment in the change in log premature atrial contractions burden, glucose, or blood pressure. Gastrointestinal changes were more common among the participants assigned magnesium (50%) than among those assigned the placebo (7%), but only one person discontinued participation. In sum, compliance with the oral magnesium supplementation was very good, and acceptance of the ZioPatch monitoring was excellent. These findings support the feasibility of a larger trial for atrial fibrillation (AF) prevention with oral magnesium supplementation.

Impact of explained v. unexplained front-of-package nutrition labels on parent and child food choices: a randomized trial.

OBJECTIVE: The present study investigated whether parent/child pairs would select more healthful foods when: (i) products were labelled with front-of-package (FOP) nutrition labels relative to packages without labels; (ii) products were labelled with colour-coded Multiple Traffic Light (MTL) FOP labels relative to monochromatic Facts up Front (FuF) FOP labels; and (iii) FOP labels were explained via in-aisle signage v. unexplained. DESIGN: Participants were randomly assigned to one of five conditions: (i) FuF labels with in-aisle signs explaining the labels; (ii) FuF labels, no signage; (iii) MTL labels with in-aisle signage; (iv) MTL labels, no signage; (v) control group, no labels/signage. Saturated fat, sodium, sugar and energy (calorie) content were compared across conditions. SETTING: The study took place in a laboratory grocery aisle. SUBJECTS: Parent/child pairs (n 153) completed the study. RESULTS: Results did not support the hypothesis that MTL labels would lead to more healthful choices than FuF labels. The presence of FOP labels did little to improve the healthfulness of selected foods, with few exceptions (participants with v. without access to FOP labels selected lower-calorie cereals, participants with access to both FOP labels and in-aisle explanatory signage selected products with less saturated fat v. participants without explanatory signage). CONCLUSIONS: Neither MTL nor FuF FOP labels led to food choices with significantly lower saturated fat, sodium or sugar. In-aisle signs explaining the FOP labels were somewhat helpful to consumers in making more healthful dietary decisions. New FOP labelling programmes could benefit from campaigns to increase consumer awareness and understanding of the labels.

Measuring perceived barriers to healthful eating in obese, treatment-seeking adults.

OBJECTIVE: To characterize perceived barriers to healthful eating in a sample of obese, treatment-seeking adults and to examine whether changes in barriers are associated with energy intake and body weight. DESIGN: Observational study based on findings from a randomized, controlled behavioral weight-loss trial. PARTICIPANTS: Participants were 113 women and 100 men, mean age 48.8 years, 67% white, and mean body mass index at baseline 34.9 kg/m(2). VARIABLES MEASURED: Perceived diet barriers were assessed using a 39-item questionnaire. Energy intake was assessed with the Block Food Frequency Questionnaire. Body weight (kg) and height (cm) were measured. ANALYSIS: Factor-based scales constructed from exploratory factor analysis. Linear regression models regressed 12-month energy intake and body weight on baseline to 12-month factor-based score changes (α = .05). RESULTS: Exploratory factor analysis yielded 3 factors: lack of knowledge, lack of control, and lack of time. Reported declines in lack of knowledge and lack of control from baseline to 12 months were associated with significantly greater energy restriction over 12 months, whereas reported declines in lack of control and lack of time were associated with significantly greater weight loss. CONCLUSIONS AND IMPLICATIONS: Results suggest that declines in perceived barriers to healthful eating during treatment are associated with greater energy restriction and weight loss.

Sex-specific HDL cholesterol changes with weight loss and their association with anthropometric variables: the LIFE study.

Decrease in the level of high-density lipoprotein cholesterol (HDLC) has been observed in women who start dieting, but not in men. Patterns of HDLC change during intentional weight loss through 30-months of follow-up, and their association with changes in anthropometric measurements were examined in obese women (N = 112) and men (N = 100). Missing HDLC values at 6-, 12-, 18-, and 30-month follow-up (N = 16, 34, 55, and 50, respectively) due to dropout were imputed by multiple imputation. Mean ages and BMIs of subjects at baseline were 47.2 years and 34.8 kg/m(2) for women, and 50.4 years and 35.0 kg/m(2) for men. On average, participants lost weight steadily for 12 months, followed by slow regain. During the first 6 months, HDLC decreased significantly in women (-4.1 mg/dl, P = 0.0007), but not in men. Significant HDLC increases were observed in both men and women from 6- to 12-month follow-up. HDLC changes in women were positively associated with changes in hip circumference from baseline to 12-month independent of changes in triglycerides (TG), glucose, and insulin. Rapid decrease of predominantly subcutaneous fat in the femoral and gluteal area might be associated with HDLC decrease in women during initial weight loss.

Maintenance-tailored therapy vs. standard behavior therapy for 30-month maintenance of weight loss.

OBJECTIVE: To assess differences in weight regain one year after an 18-month obesity treatment with standard behavior therapy (SBT) or maintenance-tailored therapy for obesity (MTT). METHOD: 213 obese adult volunteers were treated for 18 months using SBT with fixed behavioral prescriptions or MTT that employed varied behavioral prescriptions with treatment breaks. Follow-up analysis focused on weight maintenance after a year of no contact. The trial was conducted at the University of Minnesota between 2005 and 2009. RESULTS: Mean (SD) weight change between 18 and 30 months for participants in the SBT group was +4.1 kg (4.4) compared to +2.8 kg (4.5) in the MTT group. This is a 31% reduction in weight regain in MTT relative to SBT (p=0.078). This trend toward better maintenance in MTT versus SBT was due primarily to superior differential maintenance in MTT participants in the highest tertile of total weight loss at 18 months, i.e. MTT participants in this tertile regained 4 kg less than SBT participants between 18 and 30 months. CONCLUSIONS: The MTT approach with varied content and timing produced more desirable patterns of weight loss maintenance than the traditional SBT approach, especially among individuals who had achieved greater initial weight loss.

Energy density and weight change in a long-term weight-loss trial.

BACKGROUND: Health risks linked to obesity and the difficulty most have in achieving weight loss underscore the importance of identifying dietary factors that contribute to successful weight loss. METHODS: This study examined the association between change in dietary energy density and weight loss over time. Subjects were 213 men and women with BMI of 30-39 kg/m2 and without chronic illness enrolled in 2004 in a randomized trial evaluating behavioral treatments for long-term weight loss. Subjects completed a 62-item food frequency questionnaire at baseline and at 6, 12, and 18 months. RESULTS: Pearson correlations between BMI and energy density (kcals/g of solid food) at baseline were not significantly different from zero (r = -0.02, p = 0.84). In a longitudinal analysis, change in energy density was strongly related to change in BMI. The estimated beta for change in BMI (kg/m2) of those in the quartile representing greatest decrease in energy density at 18 months compared to those in the quartile with the least was -1.95 (p = 0.006). The association was especially strong in the first six months (estimated beta = -1.43), the period with greatest weight loss (mean change in BMI = -2.50 kg/m2 from 0-6 months vs. 0.23 kg/m2 from 12-18 months) and the greatest contrast with respect to change in energy density. CONCLUSION: Decreased energy density predicted weight loss in this 18 month weight loss study. These findings may have important implications for individual dietary advice and public health policies targeting weight control in the general population.

A comparison of maintenance-tailored therapy (MTT) and standard behavior therapy (SBT) for the treatment of obesity.

OBJECTIVE: To evaluate a maintenance-tailored therapy (MTT) compared to standard behavior therapy (SBT) for treatment of obesity. MAIN OUTCOME MEASURE: change in body weight. METHOD: A non-blinded, randomized trial comparing effectiveness of MTT and SBT in facilitating sustained weight loss over 18 months; 213 adult volunteers> or =18 years participated. SBT had fixed behavioral goals, MTT goals varied over time. Study conducted at the University of Minnesota, School of Public Health, January 2005 through September 2007. RESULTS: Mean (SD) weight losses at 6, 12, and 18 months were 5.7 (5.0) kg, 8.2 (8.6) kg and 8.3 (8.9) kg for MTT and 7.4 (3.9) kg, 10.7 (8.2) kg and 9.3 (8.8) kg for SBT. Total weight loss did not differ by group at 18 months, but the time pattern differed significantly (p<0.001). The SBT group lost more weight in the first 6 months. Both groups lost similar amounts between 6 and 12 months; MTT had stable weight between 12 and 18 months, while SBT experienced significant weight gain. CONCLUSIONS: The MTT approach produced sustained weight loss for an unusually long period of time and not achieved in previous trials of behavioral treatment for weight loss. The MTT approach, therefore, deserves further study.

Mood, Weight, and Physical Activity Among Obese Individuals Enrolled In a Long-term Weight-loss Program: Trajectories and Associations with Gender.

OBJECTIVE: To examine the trajectories of mood, weight and physical activity, and associations between mood, weight, and gender, among 213 obese individuals. METHODS: Prospective, longitudinal design. Assessments at baseline and 6, 12, and 18 months of Profile of Mood States, Paffenbarger Physical Activity Questionnaire, and weight. RESULTS: Total mood disturbance decreased from baseline to 6 months, with no change thereafter. Weight decreased from baseline to 6 to 12 months, and increased from 12 to 18 months. Physical activity increased from baseline to 6 months, and 12 to 18 months. Increased physical activity predicted greater vigor and less fatigue over time. Females high in distress at 6 months lost less weight than females low in distress and at 18 months gained more weight than those low in distress. There were no such associations among males. CONCLUSION: The trajectories of mood, weight and physical activity were synchronous only in the short-term. Distress monitoring, targeted to females who relapse, may be warranted.