Submitted to: Advances in Nutrition
Publication Type: Review article
Publication Acceptance Date: 1/26/2013
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: Obesity is one of the major health crises of our time. The majority of adult Americans are now either overweight or obese, and recent research indicates that obesity is approaching smoking as the major cause of disability and premature death. National improvements in dietary intake, and in particular a reversal of the documented increase in energy intake, are clearly an important key to preventing unwanted weight gain and associated comorbidities. However, there is no general consensus on how to achieve this important goal. Of the many dietary factors suggested to play an important role in the regulation of energy intake, energy density (ED) has received particular attention because small changes in the ED of the diet, if uncompensated for by alterations in the quantity of food consumed, could lead to large cumulative changes in energy intake. The ED of a food can be defined as metabolizable energy content per unit weight (kJ or kcal/g), and is determined by the macronutrient and moisture content of the food. As the most and least energy dense nutrients, fat (2.15 kJ/g [9 kcal/g]) and water (0 kJ/g) are the primary determinants of ED. Dietary energy density can be defined as the ED of the total diet. At present, no consensus has been reached on the appropriate method for calculating dietary ED, with debate centering on the inclusion of beverages in the calculation. Studies have employed different definitions of dietary ED that vary predominantly by whether some or all beverages are included in the calculation and, if so, what types. For example, some have used ED values based only on food, while some have included both food and energy-containing beverages, and others have included food and all beverages. This review summarizes information relevant to standardizing a definition of dietary ED, and provides a review of primary research publications examining the effects of ED on energy intake (EI) and body weight.