Energy density and weight change in a long-term weight-loss trial.

Andrew Flood,Patricia S Laqua,Rona L Levy,Annie Hotop,Shelby L Langer,Melanie Jaeb,Robert W Jeffery,Ericka M Welsh,Nathan Mitchell,Emily A Finch

doi:10.1186/1479-5868-6-57

Abstract

BackgroundHealth risks linked to obesity and the difficulty most have in achieving weight loss underscore the importance of identifying dietary factors that contribute to successful weight loss.MethodsThis study examined the association between change in dietary energy density and weight loss over time. Subjects were 213 men and women with BMI of 30–39 kg/m2 and without chronic illness enrolled in 2004 in a randomized trial evaluating behavioral treatments for long-term weight loss. Subjects completed a 62-item food frequency questionnaire at baseline and at 6, 12, and 18 months.ResultsPearson correlations between BMI and energy density (kcals/g of solid food) at baseline were not significantly different from zero (r = -0.02, p = 0.84). In a longitudinal analysis, change in energy density was strongly related to change in BMI. The estimated β for change in BMI (kg/m2) of those in the quartile representing greatest decrease in energy density at 18 months compared to those in the quartile with the least was -1.95 (p = 0.006). The association was especially strong in the first six months (estimated β = -1.43), the period with greatest weight loss (mean change in BMI = -2.50 kg/m2 from 0–6 months vs. 0.23 kg/m2 from 12–18 months) and the greatest contrast with respect to change in energy density.ConclusionDecreased energy density predicted weight loss in this 18 month weight loss study. These findings may have important implications for individual dietary advice and public health policies targeting weight control in the general population

Highlights

Health risks linked to obesity and the difficulty most have in achieving weight loss underscore the importance of identifying dietary factors that contribute to successful weight loss
An individual's average daily energy intake divided by the grams of food consumed per day, is a factor that could help explain the broader trends in obesity prevalence and that could serve as a potentially important point of focus in efforts to achieve weight loss
All beta estimates were derived from multivariable-adjusted models controlling for age, ethnicity, gender, change in physical activity level from baseline, and treatment group (MTT vs. Standard Behavioral Treatment (SBT)) since treatment group was related to change in body mass index (BMI) and to change in energy density (Table 1)

Summary

Introduction

Health risks linked to obesity and the difficulty most have in achieving weight loss underscore the importance of identifying dietary factors that contribute to successful weight loss. An individual's average daily energy intake divided by the grams of food consumed per day, is a factor that could help explain the broader trends in obesity prevalence and that could serve as a potentially important point of focus in efforts to achieve weight loss. Dietary energy density is associated with energy intake and weight status in a limited number of cross-sectional studies [7,8,9,10]. Higher energy density diets in feeding studies are associated with greater energy intake but not with a different volume of food consumed[11]. In the only observational analyses from a study where energy density per se was investigated as a predictor of weight change, subjects with the greatest decrease in energy density achieved the greatest weight loss[16]

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