The effects of an energy density prescription on diet quality and weight loss: a pilot randomized controlled trial

Abstract

Dietary goals specific for lowering energy density (ED) may promote a nutrient-dense diet and weight loss. This pilot study examined the effects of ED-based diet prescriptions on diet quality and weight loss during a 3-month behavior-based obesity intervention conducted in a research setting. Forty-four adults with overweight/obesity (age 52.1±7.6 years, body mass index [BMI; calculated as kg/m(2)] 34.8±4.8, 81.8% women, and 93.2% white) were recruited between December 2009 and March 2010 and randomly assigned to: Low ED (consume ≥10 foods ≤1.0 kcal/g dietary ED and ≤2 foods ≥3.0 kcal/g dietary ED per day (n=15); Low-Energy, Low-Fat (1,200 to 1,500 kcal/day, ≤30% energy from fat (n=15); or Low-ED, Low-Energy, Low-Fat (n=14). Participants received 12 weekly group sessions led by a research interventionist. Dietary intake (measured by 3-day food records), self-reported physical activity, and weight were measured at baseline and 3 months. Intent-to-treat analyses showed all conditions reduced dietary ED and energy intake (P<0.001). Low-ED and Low-ED, Low-Energy, Low-Fat interventions increased fruit consumption (P<0.05). All conditions increased self-reported physical activity (P<0.001), with no difference between conditions. Although participants in all conditions lost weight (P<0.001), those in the Low-ED condition lost more (P<0.05) than those in the Low-ED, Low-Energy, Low-Fat condition (Low-ED -20.5±7.0 lb, Low-Energy, Low-Fat -16.9±10.1 lb, and Low-ED, Low-Energy, Low-Fat -12.5± 6.5 lb). A diet prescription that lowered ED increased fruit intake and enhanced weight loss compared with other weight loss prescriptions.