Energy density, energy intake and weight status in a large free-living sample of Chinese adults: exploring the underlying roles of fat, protein, carbohydrate, fiber and water intakes.

OBJECTIVE: This paper uses observational data to explore what dietary constituents might be responsible for associations between energy density, energy intake and weight status among free-living individuals.
DESIGN: Cross-sectional data on 5783 Chinese adults (aged 20-59 y) from the 1991 China Health and Nutrition Surveys were used to test for associations between energy density, energy intake and weight status, controlling for age, sex, height, activity level, smoking status, urban residence and income. Pearson correlation coefficients were calculated to identify nutrient intake correlates of energy density. Replacing energy density with its nutrient correlates (3 day mean estimates of fat, protein, fiber and water intakes) in the models predicting energy intake and overweight status, the independent effects of specific nutrients were investigated.
RESULTS: Energy density was positively and significantly associated with energy intake and overweight status. Energy density was significantly correlated with every nutrient examined, although the correlations were weak for most variables except water intake. Only water intake behaved consistently across analyses. It was negatively correlated with energy density, negatively, significantly and independently associated with energy intake as well as overweight status. Despite positive associations with energy intake, fat and protein intake were not significant predictors of overweight status. Fiber intake was strongly and positively associated with overweight status.
CONCLUSIONS: Of the nutrients examined, only water intake appeared to explain the effects of energy density on energy intake and overweight status.