Background: While high protein diets have been shown to improve satiety and retention of lean body mass (LBM), this study was designed to determine effects of a protein- enriched meal replacement (MR) on weight loss and LBM retention by comparison to an isocaloric carbohydrate-enriched MR within customized diet plans utilizing MR to achieve high protein or standard protein intakes.~Methods: Single blind, placebo-controlled, randomized outpatient weight loss trial in 100 obese men and women comparing two isocaloric meal plans utilizing a standard MR to which was added supplementary protein or carbohydrate powder. MR were used twice daily (one meal, one snack). One additional meal was included in the meal plan designed to achieve individualized protein intakes of either 1) 2.2 g protein/kg of LBM per day [high protein diet (HP)] or 2) 1.1 g protein/kg LBM/day standard protein diet (SP). LBM was determined using bioelectrical impedance analysis (BIA). Body weight, body composition, and lipid profiles were measured at baseline and 12 weeks.
Study hypothesis: High protein diets have been shown to make people full and and help to retent of muscle mass. This study was designed to determine effects of a protein- enriched meal replacement (MR) on weight loss and muscle mass retention by comparison to an equal calorie carbohydrate-enriched MR.~Methods: Single blind, placebo-controlled, randomized outpatient weight loss trial in 100 obese men and women comparing two equal calorie meal plans.,1) 2.2 g protein/kg of LBM per day [high protein diet (HP)] or 2) 1.1 g protein/kg LBM/day standard protein diet (SP). Body weight, body composition, and lipid profiles were measured at baseline and 12 weeks.