title: Low or moderate dietary energy restriction for long-term weight loss: what works best?
abstract: Theoretical calculations suggest that small daily reductions in energy intake can cumulatively lead to substantial weight loss, but experimental data to support these calculations are lacking. We conducted a 1-year randomized controlled pilot study of low (10%) or moderate (30%) energy restriction (ER) with diets differing in glycemic load in 38 overweight adults (mean +/- s.d., age 35 +/- 6 years; BMI 27.6 +/- 1.4 kg/m(2)). Food was provided for 6 months and self-selected for 6 additional months. Measurements included body weight, resting metabolic rate (RMR), adherence to the ER prescription assessed using (2)H(2)(18)O, satiety, and eating behavior variables. The 10%ER group consumed significantly less energy (by (2)H(2)(18)O) than prescribed over 12 months (18.1 +/- 9.8%ER, P = 0.04), while the 30%ER group consumed significantly more (23.1 +/- 8.7%ER, P < 0.001). Changes in body weight, satiety, and other variables were not significantly different between groups. However, during self-selected eating (6-12 months) variability in % weight change was significantly greater in the 10%ER group (P < 0.001) and poorer weight outcome on 10%ER was predicted by higher baseline BMI and greater disinhibition (P < 0.0001; adj R(2) = 0.71). Weight loss at 12 months was not significantly different between groups prescribed 10 or 30%ER, supporting the efficacy of low ER recommendations. However, long-term weight change was more variable on 10%ER and weight change in this group was predicted by body size and eating behavior. These preliminary results indicate beneficial effects of low-level ER for some but not all individuals in a weight control program, and suggest testable approaches for optimizing dieting success based on individualizing prescribed level of ER.
authors.affiliation: Energy Metabolism Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, Massachusetts, USA.
authors.forename: Sai Krupa
authors.initials: SK
authors.lastname: Das
authors.forename: Edward
authors.initials: E
authors.lastname: Saltzman
authors.forename: Cheryl H
authors.initials: CH
authors.lastname: Gilhooly
authors.forename: James P
authors.initials: JP
authors.lastname: DeLany
authors.forename: Julie K
authors.initials: JK
authors.lastname: Golden
authors.forename: Anastassios G
authors.initials: AG
authors.lastname: Pittas
authors.forename: Gerard E
authors.initials: GE
authors.lastname: Dallal
authors.forename: Manjushri V
authors.initials: MV
authors.lastname: Bhapkar
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Fuss
authors.forename: Chhanda
authors.initials: C
authors.lastname: Dutta
authors.forename: Megan A
authors.initials: MA
authors.lastname: McCrory
authors.forename: Susan B
authors.initials: SB
authors.lastname: Roberts
mesh_terms: D000328:Adult; D001481:Basal Metabolism; D031204:Caloric Restriction / Q000379:methods*; D002149:Energy Intake; D004734:Energy Metabolism; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D006815:Hunger; D007206:Individuality; D008297:Male; D009043:Motor Activity; D050177:Overweight / Q000178:diet therapy*; D010349:Patient Compliance / Q000706:statistics & numerical data; D010865:Pilot Projects; D012528:Satiety Response; D013997:Time Factors; D016896:Treatment Outcome; D015431:Weight Loss; D055815:Young Adult