Dietary energy density (ED) may be a good predictor of weight gain because of its association with the regulation of appetite control signals. Among the participants of the 'SUpplementation en VItamines et Mineraux AntioXydants' prospective study, 2707 subjects were included in the present study. Changes in weight, waist circumference (WC), hip circumference (HC) and waist:hip ratio were calculated using measured data collected in 1995/1996 and 2001/2002. The mean changes in various anthropometric indicators according to baseline body-weight status (BMI , or $25 kg/m 2 ) and sex-specific tertiles of baseline ED level or 6-year changes in ED were compared by covariance analysis. In overweight subjects, weight gain was positively associated with high dietary ED at baseline (P for trend ¼ 0·03) and with increasing ED during the follow-up (P for trend ¼ 0·0008). Both the WC and HC changes were also positively related to baseline ED and change in ED in overweight subjects. However, the relationships observed for the WC and HC changes were no longer significant after adjustment for weight change. These results support the hypothesis of a deleterious effect of high-energy-dense diets on weight change for overweight subjects. This relationship could be mediated by physical activity level. Further research needs to be performed in other populations to determine whether ED could be effective strategies to prevent weight gain.
Body fat distribution: Cohort studies: Diet quality: Energy density: Weight changeObesity has become the most frequent nutritional problem in industrialised countries and its prevalence is still increasing (1,2) . Obesity constitutes a major public-health concern because of its implication in the development of several chronic diseases, such as type 2 diabetes, as well as of CVD and certain cancers (1) .Weight gain is due to a positive energy balance, either caused by a decrease in energy expenditure or an increase in energy intake (EI). It is now well recognised that both decreasing physical activity (PA) levels and changes in diet are involved in the obesity epidemic (3) . Among dietary factors, dietary energy density (ED) is of growing interest (1,4) , particularly regarding socio-economic disparities in diet quality and obesity (5 -7) . ED may be a key element in body-weight regulation because it may alter appetite control signals, namely hunger and satiety (8,9) . Some studies have reported positive associations between ED and EI (4,10,11) . In addition, there is a strong correlation between the ED of foods and their fat content (4,12) , which may also encourage weight gain.However, the results from cross-sectional epidemiological studies that have examined the relationships between dietary ED and body-weight status are not consistent (10,13 -20) .Some of them found a positive relationship between ED and weight (10,14,15,19) , whereas some others found no significant association (13,20) or only in men (16) . Among the few longitudinal analysis available in free-living subjects, two were perfor...