Higher protein diet for weight management in young overweight women: A 12-month randomized controlled trial

Clinical research on weight management in young women is limited. This randomized controlled trial compared the efficacy of two iso-energetically restricted (5600 kJ) diets [higher protein (HP): 32% protein, 41% carbohydrate, 25% fat or higher carbohydrate (HC): 20, 58, 21%, respectively] in 71 (HP: n=36; HC: n=35) young healthy women (18-25 years; body mass index≥27.5kg/m²) for weight (kg; percent weight loss), body composition, metabolic and iron changes assessed at baseline, 6 and 12 months. Data: mean (95% CI). In HP completers at 6 months, percent weight loss was higher [HP: 9.3 (5.6-13.1); HC: 5.1 (2.3-7.9)%; p=0.06]; although, this did not reach statistical significance. Absolute weight [HP: 8.9 (5.3-12.5); HC: 4.6 (2.2-7.0) kg; p=0.034] and fat loss [HP: 8.0 (4.4-11.5); HC: 3.4 (1.3-5.6) kg; p=0.022] were significantly greater. No significant between-diet differences were observed at 12 months. Biochemistry remained within normal ranges with HP showing superior preservation of ferritin at 6 months [HP: 53 (40-66); HC: 46 (30-61) μg/l; p=0.029]. Both diets supported clinically meaningful weight loss with HP tending to be more effective in the medium-term.