The three dietary conditions were processed foods (PF) cafeteria diet, natural foods (NF) cafeteria diet, or chow-only control (CON). Condition assignments were pseudo-random by litter and weight, with two rats from each litter assigned to each condition to create experimental groups matched for initial body weight. CON rats received a standard cereal-based rodent chow ad libitum (Mazuri Laboratory Rodent Diet 5663, 3.41 kcal/g, 14% energy from fat, 27% from protein, 59% from carbohydrate). Cafeteria groups received the same chow plus limited portions each day of two or three different foods from their cafeteria diet. Water was available ad libitum.