POVERTY AND OBESITY: DIET QUALITY, ENERGY DENSITY, AND ENERGY COSTS

Authors: DREWNOWSKI, ADAM - UNIV OF WASHINGTON; SPECTER, S - USDA, ARS, WHNRC

Submitted to: The American Journal of Clinical Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/9/2003
Publication Date: 6/9/2003
Citation: Drewnowski, A., Specter, S.E. 2004. Poverty and obesity: diet quality, energy density, and energy costs. American Journal of Clinical Nutrition. 79:6-16.

Interpretive Summary: Consumer food choices are driven by considerations of taste, cost, convenience, and to a lesser extent, by health and variety. Research has linked growing obesity rates with increased consumption of snack and fast foods, soft drinks, and with high energy density of the total diet. What these foods have in common is low energy cost, due in part to the presence of added sugars and fat. Some nutrition professionals have already noted that diets of lower socioeconomic groups provide cheap, concentrated energy from fat, sugar, cereals, potatoes and meat products, but very little intake of vegetables, fruit and whole grains. Our central hypothesis is that limited economic resources may shift dietary choices towaqrd an energy-dense, highly palatable diet that provides maximum calories per least volume and least cost. Reducing the energy density of the diet is a worthy objective; the question is, can it be achieved without simultaneously increasing the cost and reducing the palatability of the diet?

Technical Abstract: Health disparities among U.S. populations are linked to inequalities in education and income. Highest rates of obesity and diabetes occuramong groups with highest poverty rates and the least education. The present model focuses on socioeconomic influences on diet structure, and on the relationship between diet quality, energy density, and energy costs. Evidence is provided to support the following points. First, foods high in energy density (MJ/g) are associated with high palatability and low energy costs ($/10MJ). Simple sugards and vegetable oils can provide as much as 80,000 kJ per dollar. Second, energy-dense diets high in refined grains , sweets, and fats are far less than equicaloric "prudent" diets based on lean meats, fish, fresh vegetables, and fruit. Reducing diet costs in linear programming models leads to high-fat, energy-dense diets, similar in structure to those condumed by low-income groups. Third, high energy density of the diet (MJ/kg) has been associated with higher energy intakes, at leas in clinical and laboratory studies. Finally, poverty and food insecurity are associated with lower food spending and with lower-quality diets. Excessive energy intakes may be mediated, in part, by low dietary energy costs and reinformed by the high palatability of sweet and high-fat foods. The present model provides an economic explanation for the observed links between socioeconomic variables and obesity, using taste, dietary energy density, and diet costs as the intervening variables. More and more Americans are becoming overweight and obese while consuming more added sugars and fats and spending a lower percentage of their disposable income for food.