Nutrition science is beginning to place less emphasis on the nutrient composition of the diet and more emphasis on its comprising foods. A particular public health concern involves the consumption of foods that result from extensive industrial processing. Ultra-processed foods have becoming increasingly common and now contribute the majority of calories consumed in America. The rise in the prevalence of obesity, type 2 diabetes, and metabolic syndrome over the past several decades is believed to have been caused, in part, by the parallel increase in production, advertising, and consumption of ultra-processed foods. However, the metabolic effects of industrial processing per se, independent of diet calories or macronutrient composition, have not been carefully investigated in a controlled feeding study. Therefore, we will conduct an inpatient controlled feeding study in 20 overweight and obese adult men to investigate the changes in multi-organ insulin sensitivity and hepatic triglyceride content resulting from consuming two test diets for a pair of 3 week periods. The test diets will be implemented in a randomized, crossover design with each test diet following a 1 week run-in period of inpatient controlled feeding of a standard metabolic diet. The test diets will be matched for calories, macronutrient composition, sugar, fiber, and sodium, but one diet will be composed of ultra-processed foods whereas the other diet will be unprocessed foods. Multi-organ insulin sensitivity and hepatic triglyceride content will be measured at the end of each 1 week run-in period as well as at the end of each 3 week test diet period.