Initial weight loss goals: have they changed and do they matter?

OBJECTIVE: Nearly 20 years ago, participants in behavioural weight loss programmes reported goals that greatly exceeded the amount of weight typically produced by these programmes. Whether having unrealistic weight loss goals impacts weight loss or attrition is unclear. The intent of the current study was to revisit current weight loss goals and examine whether goals impact outcomes. METHODS: Adults (N = 308, BMI = 33.7 ± 4.2 kg/m2) participated in a 12-month behavioural weight management programme and completed questionnaires about their goals. RESULTS: Participants' weight loss goal was 19.8 ± 7.9% of their body weight, and 90.4% selected a goal ≥10%. Weight goals were not associated with weight loss at 3 (p = 0.75) or 12 months (p = 0.47), or from 3 to 12 months (p = 0.55). Weight loss goals were not related to attrition at 3 (p = 0.91) or 12 months (p = 0.86). Participants believed that weight reduction would positively impact their health and psychosocial functioning. CONCLUSION: Weight loss goals have decreased, but still greatly exceed what can be expected by most. Unrealistic goals, however, had no impact on weight loss or attrition. These results question the utility of counseling people with obesity to set more realistic weight loss goals, which is typically practiced in behavioural weight management.

Similar effects on cognitive performance during high- and low-carbohydrate obesity treatment.

OBJECTIVE: Low-carbohydrate (L-CHO) diets are often used for weight loss but their effects on cognitive function are not well understood. The present study compared the effects of a L-CHO and high-carbohydrate (H-CHO) weight-loss diet on cognitive function adults. DESIGN: PARTICIPANTS were randomized to either a L-CHO (n=22) or H-CHO (n=25) weight-loss diet. Cognitive function was evaluated by four computerized cognitive tasks (Stroop Task, Continuous Performance Task, Word Recall and Wisconsin Card Sorting Task) presented in random order before and at 1, 4, 12 and 24 weeks after the initiation of the L-CHO or H-CHO diet. PARTICIPANTS: Forty-seven adults (25 males) with a mean±s.d. age of 47.4±8.7 years and body mass index of 35.3±3.4 kg m(-2). RESULTS: There were no significant differences in weight loss between groups at any time point. There were significant improvements on color Stroop task accuracy over time in both diet groups (P<0.05), but there were no differences in performance between groups on this or any other cognitive task at any time period. CONCLUSION: These findings suggest that weight loss has neither a positive nor a negative effect on cognitive function and that L-CHO and H-CHO weight-loss diets have similar effects on cognitive performance.

A randomized comparison of a commercially available portion-controlled weight-loss intervention with a diabetes self-management education program.

OBJECTIVE: This study examined the efficacy of a commercially available, portion-controlled diet (PCD) on body weight and HbA1c over 6 months in obese patients with type 2 diabetes. RESEARCH DESIGN AND METHODS: One-hundred participants with a mean±s.d. age of 55.6±10.6 year, body weight of 102.9±18.4 kg and HbA1c of 7.7±1.3% were randomly assigned to a 9-session group lifestyle intervention that included a PCD or to a 9-session group program of diabetes self-management education (DSME). Participants in the two groups were prescribed the same goals for energy intake (1250-1550 kcal per day) and physical activity (200 min per week). RESULTS: While both groups produced significant improvements in weight and HbA1c after 6 months of treatment, PCD participants lost 7.3 kg [95% confidence interval (CI): -5.8 to -8.8 kg], compared with 2.2 kg (95% CI: -0.7 to -3.7 kg) in the DSME group (P<0.0001). Significantly more PCD than DSME participants lost 5% of initial weight (54.0% vs 14.0%, P<0.0001) and 10% (26.0% vs 6.0%, P<0.0001). HbA1c declined by 0.7% (95% CI: -0.4 to -1.0%) in the PCD group, compared with 0.4% (95% CI: -0.1 to -0.7%) in DSME (P<0.026). Across both groups, larger weight losses were associated with greater reductions in HbA1c (r=0.52, P<0.0001). CONCLUSIONS: These findings demonstrate that a commercially available portion-controlled meal plan can induce clinically meaningful improvements in weight and glycemic control in obese individuals with type 2 diabetes. These data have implications for the management of obesity in primary care, as now provided by the Centers for Medicare and Medicaid Services.