Given the variety of weight loss approaches available to your patients, what works and what are realistic expectations of your patients keeping the weight off? Researchers at HealthPartners Health Behavior Group and Kaiser Permanente’s Care Management Institute set out to answer that question by conducting a systematic review of the literature to determine the effectiveness of eight types of weight-loss interventions.

Objective:
To determine types of weight-loss interventions that lead to successful outcomes and to define expected weight-loss outcomes from such interventions.

Methods:
Eighty studies meeting the study inclusion criteria were included in the review, with a total of 26, 455 subjects enrolled and randomized. The primary outcomes were a measure of weight loss at 6, 12, 24, 36 and 48 months. Eight types of weight loss interventions were considered:

1. Diet alone
2. Diet and exercise
3. Exercise alone
4. Meal replacements
5. Very-low-energy diets
6. Weight-loss medications (orlistat and sibutramine)
7. Advice alone

Results:
Diet alone - Mean weight loss at 6 months of 4.9 kg (5%), maintaining a mean weight loss of 4.6 to 4.4 to 3.0 kg (4.6%, 4.4%, 3.0%) at 12, 24, and 48 months, respectively.

Diet and exercise - Mean weight loss of 7.9 kg (8.5%) at 6 months; weight-loss plateaus to 12 months and at 36 and 48 months is maintained at 3.9 kg (4%).

Meal replacements - Mean weight loss of 8.6 to 6.7 kg (9.6% to 7.5%) at 6 and 12 months, respectively.

Very-low-energy diets - Mean weight loss of 17.9 kg (16%) at 6 months followed by a rapid regain so that at 12 months the mean weight loss was 10.9 kg (10%) and by 36 months, 5.6 kg (5%).

Weight-loss medications - Subjects taking orlistat at 6 months experienced a mean 8.3 kg (8%) weight loss at 6 months, and a mean 8.2 kg, 7.7 kg, 7.8 kg, and 5.8 kg (8%, 7%, 7% and 5.3%) at 12, 24, 36, and 48 months, respectively. Subjects taking sibutramine at 6 months experienced a mean 8.2 kg (8.4% and 11%) at 12 and 24 months, respectively.

Exercise alone - Mean 2.4 kg (2.7%) weight loss at 6 months and a mean 1.0 kg (1.0%) at 24 months.

Advice alone - Minimal/no weight loss across all time points.

	Average weight loss of subjects completing a minimum 1-year weight-management intervention; based on review of 80 studies (n=26,455; 18,199 completers (69%)

CONCLUSION:
Based on data from published clinical trials, weight loss approaches involving attention to reducing food intake—diet alone, diet and exercise, meal replacements, and weight loss medications combined with diet—appear to produce the most encouraging short-term results. While weight loss appears to plateau at approximately 6 months across all the interventions, continued healthcare professional support can help sustain weight-loss maintenance. Importantly, these modest weight loss results are of clinical significance as they relate to the associated health benefits.

Sources:
Weight-loss outcomes:  a systematic review and meta-analysis of weight-loss clinical trials with a minimum 1-year follow-up.  Franz, MJ, et al. J Am Diet Assoc. 2007;107:1755-1767.