Obesity in the United States is in part an economic issue, according to a review paper on the relationship between poverty and obesity published in the American Journal of Clinical Nutrition.

The paper is by Dr. Adam Drewnowski, director of the Center for Public Health Nutrition in the University of Washington School of Public Health and Community Medicine, and Dr. S.E. Specter, research nutrition scientist at the U.S. Department of Agriculture Human Nutrition Research Center in Davis, Calif.

“It’s a question of money,” Drewnowski said. “The reason healthier diets are beyond the reach of many people is that such diets cost more. On a per calorie basis, diets composed of whole grains, fish, and fresh vegetables and fruit are far more expensive than refined grains, added sugars and added fats. It’s not a question of being sensible or silly when it comes to food choices, it’s about being limited to those foods that you can afford.”