Gene-Environment Interaction and Precision Nutrition on Adiposity, Glycemic, Lipids Changes, and Bone Health

The epidemic of obesity has become a major public health problem. Obesity is a multifactorial abnormality that has a genetic basis but requires environmental influences to manifest. Common-form obesity is underpinned by both environmental and genetic factors. Recent genome-wide association studies have identified several genes convincingly related to obesity risk. Testing gene-environment interaction is a relatively new field. Evidence from association studies and intervention trials continues to mount, indicating that genetic components may modify lifestyle effects on the development of obesity. However, these findings are at most preliminary. The interplay between genetic and environmental components may facilitate the choice of more effective and specific measures for obesity prevention based on personalized genetic make-up. The investigators aimed to examine whether the genetic variation affected glycemic, waist circumference, body weight, visceral fat and lipids changes in response to weight-loss dietary intervention varying in macronutrient intake (target percentages of energy derived from fat, protein, and carbohydrate in the 4 diets were as follows 20%, 15% and 65%; 20%, 25%, and 55%; 40%, 15%, and 45%; and 40%, 25%, and 35%). The primary outcome is to test the interactions between the genes and diet interventions varying in macronutrient intake on body weight changes. The secondary outcome is to test the interactions between the genes and diet interventions varying in macronutrient intake on glycemic, waist circumference, visceral fat, and lipids changes. Understanding gene-diet interactions in relation to weight loss hold great promise for delivering more efficient prevention and treatment on obesity and related metabolic disorders. In addition, besides gene-diet interactions, the investigators will also conduct other precision nutrition analysis. These analyses include interactions between pretreatment factors with diet intervention adiposity traits, initial changes induced by diet intervention with various outcomes measured in POUNDS Lost, including body weight, waist circumference, body composition, ectopic fat, and bone health.