Evaluating the Effects Two Diets Combined With Exercise in Persons With Abdominal Obesity (The SHAPE5 Study)
Condition: Overweight; Obese; Sedentary; Abdominal Obesity
MeSH terms: Obesity; Overweight; Obesity, Abdominal
Study type: Interventional
Phase: Phase 3

Summary: 
      Abdominal obesity, which is affected by a lack of physical activity and excess weight, put
      people at an increased risk of cardiovascular disease. This study will compare the effects of
      two different dietary approaches to weight loss, each combined with exercise, for their
      effects on cardiovascular factors that are early predictors of future cardiovascular disease
      in overweight and obese people with excessive weight around their waist. The two diets are a
      low-carbohydrate versus a more traditional low-fat, low calorie diet.
    

Detailed description: 
      Abdominal obesity is a condition that is largely influenced by a poor diet and physical
      inactivity. This condition has adverse effects on heart and blood vessel structure and
      function, including left ventricular diastolic dysfunction, endothelial vasodilator
      dysfunction, and increased vascular stiffness, each of which increase the risk of
      cardiovascular disease. Reducing the amount of calories consumed and increasing physical
      activity are both important factors for losing weight, increasing fitness, and improving
      blood glucose control. However, little research has been conducted on comparing different
      diet approaches combined with exercise for their effects on general and abdominal obesity,
      fitness, heart and blood vessel structure and function, and heart disease risk factors. The
      purpose of this study is to determine whether people who follow low-carbohydrate diet or a
      low-fat, low-calorie diet, each combined with a supervised experience similar improvements in
      cardiovascular and in body composition and health.

      This study will enroll people who are overweight or obese and abdominal obesity, defined as a
      waist to hip ratio greater than 1, or a waist size of 40" or greater in men or 35" or greater
      in women. Participants will attend baseline study visits and complete blood pressure
      measurements; muscle strength measurements; a treadmill test to evaluate cardiovascular
      fitness; an echocardiogram to obtain images of the heart; tests to measure blood vessel
      function; a dual energy x-ray absorptiometry (DEXA) scan to measure body fat, muscle tissue,
      and bone density; questionnaires to assess physical activity levels, quality of life, and
      mood; and a blood collection. A portion of blood will be stored for future genetic testing.
      Women will also provide a urine sample for pregnancy testing. Participants will also keep a
      food diary for 3 days. Participants will then be randomly assigned to either a
      low-carbohydrate or a low-fat, low-calorie weight loss diet, each combined with a supervised
      exercise program. . The exercise program will be done three times a week for 6 months. Each
      session will last 1 to 1 ½ hours and will include aerobic exercise and weight training.

      All participants will attend study visits with a dietitian for weight loss counseling and
      monitoring once a week during Months 1 and 2, and every other week in Months 3 through 6. At
      each of these visits, participants' weight will be measured.

      At the end of Month 6, all participants will attend a study visit for repeat baseline
      testing. In addition, there will another test for vascular function, BP, weight, and waist
      and hip measurements at the time a participant loses ten pounds.
    

Intervention name(s): Weight Loss Diets Plus Exercise
Intervention type(s): Behavioral
Intervention description(s): The weight loss diet will be either a low-carbohydrate diet or a low-fat, low-calorie diet. All participants will also be enrolled in a supervised exercise program.
The supervised exercise training sessions will take place three times a week for 6 months. Each session will last 1 to 1 ½ hours and will include aerobic exercise and weight training.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Exercise; Weight loss diet; Obesity; Overweight; Abdominal obesity; Cardiovascular function; Body composition