As a result, the amount of wild and homegrown foods in the AI/AN diet has diminished, and a greater proportion of food is processed and commercially prepared, a trend also seen among the whole U.S. population. Diets historically high in complex carbohydrate/high fiber foods and lower in fat have been replaced by foods high in refined carbohydrates (e.g. refined sugars), fat, sodium, and low in fruits and vegetables (IHS, 2001).
...
Kumanyika and Grier (2006) review evidence that indicate the higher rates of obesity in racial and ethnic minority and low income communities are associated with a plethora of unfavorable influences - economic stresses, reduced access to affordable healthful foods, opportunities for safe and varied physical activity, overexposure to targeted advertising, and marketing of energy-dense foods.