Interactions of diet, exercise, metabolism, and weight change in humans

National Institute Of Diabetes And Digestive And Kidney Diseases

Investigators

Linked publications & trials

Abstract

We continue to investigate the effects of various diet manipulations on human physiology. To investigate the potential roles of non-beverage energy density and hyper-palatable foods in determining increased ad libitum energy intake of diets high in UPFs, we will study 36 adult men and women to investigate the differences in mean daily ad libitum energy intake resulting from consuming four test diets, each for a 1-week period in a randomized, crossover design (NCT05290064). Two of the test diets are similar to those used in our previous study, where the unprocessed diet was low in both non-beverage energy density and hyper-palatable foods, whereas the high UPF diet was high in both of these variables. Two reformulated high UPF diets have been designed, one that is low in both non-beverage energy density and hyper-palatable foods and the other is high in non-beverage energy density but low in hyper-palatable foods. All four test diets are matched for daily presented energy, macronutrients, sugar, and fiber. By comparing mean daily ad libitum energy intake between the four test diets, this study will elucidate the relative contributions of non-beverage energy density and hyper-palatable foods to excess energy intake in high UPF diets. We have initiated a new randomized placebo controlled trial to investigate whether nicotinamide riboside supplementation enhances ketosis and sleeping energy expenditure when transitioning from a eucaloric standard run in diet to a ketogenic diet in men and women with overweight and obesity. We are also investigating the effects of diet order between low carbohydrate and low fat diets on body weight and body composition. Secondary analysis of data from our previous crossover inpatient trial revealed large diet order effects and we are designing a new study to see if these effects persist in an outpatient population over a longer duration in the context of a controlled feeding study designed to induce weight loss in participants with obesity.