The Effect of 12 Weeks of Equicaloric High Protein Diet in Regulating Appetite and Body Composition of Women With Normal Weight Obesity: A Randomized Controlled Trial

Br J Nutr. 2020 Jun 9;1-20. doi: 10.1017/S0007114520002019. Online ahead of print.

Abstract

Normal weight obesity (NWO) syndrome is associated with metabolic diseases. The present study aimed to investigate the effects of 12 weeks of a high-protein (HP) versus a standard protein (SP) diet on appetite, anthropometry, and body composition in NWO women. In this clinical trial, 50 NWO women were randomly allocated to an HP (n=25) or an SP (n=25) diet groups. Women in the HP and SP groups consumed 25% and 15% of their total energy intake from protein for 12 weeks. Weight, fat mass (FM), lean body mass (LBM), waist circumference (WC), and appetite were evaluated at baseline and following their three-month intervention. After 12 weeks, the LBM was higher in HP compared to no significant changes in the SP group [mean between-group difference= 1.5 kg (95% confidence interval {CI}, 3.1 to 0.01, effect size {d}= 0.4)]. Furthermore, the HP group had lower FM [mean between-group difference, -1.1 kg (95% CI, 1 to -3.3; d= -0.2)], body fat percentage (BFP) [mean between-group difference, -2 % (95% CI, 0.7 to -5.2; d= -0.3)] and WC [mean between-group difference, -1.4 cm (95% CI, 0.6 to -3.6; d= -0.2)] at the end of the study in comparison to the SP group. In both groups, weight and appetite were unchanged over time without significant differences between groups. 12 weeks of eucaloric diets with different dietary protein content resulted in no significant weight loss in women with NWO. However, an HP diet significantly improved body composition (LBM, FM, BFP, and WC) in this population.

Keywords: Diet; Normal weight obesity; Obesity; body composition; high protein diet; weight loss.