Dieting is more effective in reducing weight but exercise is more effective in reducing fat during the early phase of a weight-reducing program in healthy humans.

@article{Tsai2003DietingIM,
  title={Dieting is more effective in reducing weight but exercise is more effective in reducing fat during the early phase of a weight-reducing program in healthy humans.},
  author={Alan Chung-hong Tsai and Anita M Sandretto and Yu Chia Chung},
  journal={The Journal of nutritional biochemistry},
  year={2003},
  volume={14 9},
  pages={541-9}
}
This study compared the relative effectiveness of two means of energy deficit, food restriction (FR) and increased physical activity (EX), on body weight, body composition and concentrations of serum leptin, insulin, glucose, and lipids in female subjects. Thirteen adult female volunteers participated in a two-phase crossover-treatment study. Each phase involved a 9-day energy deficit period and a 5-day follow up energy repletion period. A 25% energy deficit was achieved by either FR or EX… CONTINUE READING