Caloric Restriction, Exercise, and Glucoregulation in Humans

Caloric Restriction, Exercise, and Glucoregulation in Humans

Weight loss induced by caloric restriction alone (CR) and by exercise alone (EX) result in similar effects on blood glucose and insulin. The purpose of this study is to assess the hypothesis that weight loss through caloric restriction plus exercise will result in greater improvements on glucose tolerance and insulin action than similar weight losses through CR or EX alone.

Participants are randomized into caloric restriction, exercise, and caloric restriction plus exercise weight loss groups. Measurements of blood glucose and insulin, oral glucose tolerance, and matched glucose infusion will be done at baseline and after weight loss of 6% of body weight. Other tests include maximal oxygen uptake (VO2max), strength tests, blood pressure, blood lipids, serum inflammatory markers, dual X-ray absorptiometry (DEXA) for bone density and body composition, physical activity levels, dietary intakes, and measures of arterial stiffness.

Inclusion Criteria:

• females postmenopausal
• no diabetes, cardiovascular disease, cancer
• no orthopedic problems
• not currently exercising
• BMI between 25 and 29.9
• nonsmokers

Exclusion Criteria:

• current regular exercisers
• premenopausal women
• cardiovascular disease, lung disease, cancer, diabetes