Randomized trial of lifestyle modification and pharmacotherapy for obesity

N Engl J Med. 2005 Nov 17;353(20):2111-20. doi: 10.1056/NEJMoa050156.


Background: Weight-loss medications are recommended as an adjunct to a comprehensive program of diet, exercise, and behavior therapy but are typically prescribed with minimal or no lifestyle modification. This practice is likely to limit therapeutic benefits.

Methods: In this one-year trial, we randomly assigned 224 obese adults to receive 15 mg of sibutramine per day alone, delivered by a primary care provider in eight visits of 10 to 15 minutes each; lifestyle-modification counseling alone, delivered in 30 group sessions; sibutramine plus 30 group sessions of lifestyle-modification counseling (i.e., combined therapy); or sibutramine plus brief lifestyle-modification counseling delivered by a primary care provider in eight visits of 10 to 15 minutes each. All subjects were prescribed a diet of 1200 to 1500 kcal per day and the same exercise regimen.

Results: At one year, subjects who received combined therapy lost a mean (+/-SD) of 12.1+/-9.8 kg, whereas those receiving sibutramine alone lost 5.0+/-7.4 kg, those treated by lifestyle modification alone lost 6.7+/-7.9 kg, and those receiving sibutramine plus brief therapy lost 7.5+/-8.0 kg (P<0.001). Those in the combined-therapy group who frequently recorded their food intake lost more weight than those who did so infrequently (18.1+/-9.8 kg vs. 7.7+/-7.5 kg, P=0.04).

Conclusions: The combination of medication and group lifestyle modification resulted in more weight loss than either medication or lifestyle modification alone. The results underscore the importance of prescribing weight-loss medications in combination with, rather than in lieu of, lifestyle modification.

Publication types

  • Randomized Controlled Trial
  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Appetite Depressants / adverse effects
  • Appetite Depressants / therapeutic use*
  • Cardiovascular Diseases
  • Combined Modality Therapy
  • Counseling
  • Cyclobutanes / adverse effects
  • Cyclobutanes / therapeutic use*
  • Exercise
  • Female
  • Humans
  • Life Style*
  • Male
  • Middle Aged
  • Obesity / drug therapy
  • Obesity / physiopathology
  • Obesity / therapy*
  • Psychotherapy, Group*
  • Risk Factors
  • Serotonin Uptake Inhibitors / adverse effects
  • Serotonin Uptake Inhibitors / therapeutic use
  • Weight Loss / drug effects


  • Appetite Depressants
  • Cyclobutanes
  • Serotonin Uptake Inhibitors
  • sibutramine