exercise after clinically significant weight loss

Conditions: Obesity; Sedentary Lifestyle; Insulin Resistance

Summary: the prescribed exercise to reduce recidivism after weight loss pilot (prevail-p) study will evaluate the effect of aerobic exercise training amount on weight maintenance following clinically significant weight loss.

the prescribed exercise to reduce recidivism after weight loss pilot (prevail-p) study will evaluate the effect of aerobic exercise training amount on weight maintenance following clinically significant weight loss (cwl). overweight and obese (bmi: 25-40 kg/m2) men and women (18-65 years old) complete an optifast diet (7%-10% weight loss). participants that obtain cwl will be subsequently randomized to aerobic exercise training consistent with the minimum physical activity guidelines (\~150 min of moderate intensity exercise) or weight maintenance guidelines (200-300 min per wk. at moderate intensity) for 9 additional months. specific aim 1: to demonstrate the efficacy of the weight loss program in producing cwl and retention/adherence of the exercise intervention. overweight and obese adults (n=39) will participate in an optifast weight loss program and supervised aerobic exercise training (\~550 metabolic equivalents minutes \[met min. per week.\]) for 10 weeks. participants who obtain cwl will be subsequently randomized to 16 weeks of aerobic training consistent with the minimum physical activity recommendations (\~550 met min per week.) or weight maintenance guidelines (\~970 met min per week). the percentage of participants that obtain at least 7% weight loss following optifast treatment, retention rates in the weight loss program, adherence to exercise levels, and changes in weight and cardiometabolic risk factors in response to the intervention will be evaluated. specific aim 2: to test the hypothesis that exercise levels consistent with weight maintenance recommendations leads to greater weight maintenance after cwl compared to the minimum physical activity recommendation levels. overweight and obese adults (n=30) enrolled in vidant health's optifast program and have achieved at least 7% weight loss will be randomized to 36 weeks of aerobic exercise training consistent with the minimum public health guidelines for physical activity (\~550 met min. per week.) or weight maintenance levels (\~970 met min per week). the effect of the intervention will be evaluated on weight (primary) as well as main secondary measures (e.g. body fat, visceral fat, lipids, lipoprotein particles size/class, insulin sensitivity, blood pressure, arterial stiffness, systemic inflammation, fitness, and quality of life). the aforementioned cardiometabolic risk factors were selected because they can be improved specifically by weight loss and thus may respond differently to weight maintenance or regain.

Eligibility criteria:
inclusion criteria: * men and women 18-65 years of age (postmenopausal females permitted) * body mass index: 25-39.9 kg/m2 at enrollment * the capability and willingness to provide written informed consent * willingness to accept group assignment from randomization * no resistance training and no structured aerobic exercise for \> 20 minutes per day, 3+ days per week, for the last 6 months * conditions that are contraindicated for exercise training exclusion criteria: * resting blood pressure \> 180 mm hg systolic and/or \>100 mm hg diastolic (individuals on blood pressure medications meeting the blood pressure criteria are eligible) * diagnosis of type 1 or 2 diabetes, and/or fasting glucose \>125 mg/dl * medication for the treatment of type 1 or type 2 diabetes * bariatric surgery including gastric banding or bypass (potential effects on energy intake) * factors that may limit adherence to intervention or affect conduct of the trial * unable or unwilling to communicate with staff * failure to complete run-in or baseline testing * hospitalization for depression or severe mental illness in the last 6 months * not physically capable of performing the exercise required of the study protocol * consuming more than 14 alcoholic beverages per week * plan to be away from the pitt county area more than 3 weeks in the next 3 months * lack support from a primary health care provider or family members * significant weight loss in the past year (\> 20 pounds) or are currently using weight loss medications. * current diagnosis of schizophrenia, other psychotic disorders, or bipolar disorder * other temporary intervening event, such as sick spouse, or bereavement * other medical, psychiatric, or behavioral limitations that may interfere with study participation or the ability to follow the intervention protocol * underlying diseases or conditions likely to limit lifespan and/or affect the safety of the intervention * cancer requiring treatment in the past 5 years with anything but excellent prognosis * self-reported hiv, tuberculosis, hepatitis b, or hepatitis c * history or evidence of serious arrhythmias, cardiomyopathy, congestive heart failure, aortic aneurism, myocardial infarction or heart transplantation * renal disease: urine protein \> 100 mg/dl, serum creatinine ≥ 1.5 mg/dl or currently receiving dialysis. * auto-immune diseases (such as lupus, multiple sclerosis, graves' disease, or rheumatoid arthritis) * chronic obstructive lung disease, peripheral vascular disease or angina that limits ability to follow exercise protocol * history of stroke or transient ischemic attack * history of vascular aneurysms * history of bleeding disorders * pregnancy or plans to become pregnant * any other medical condition or disease that is life threatening or that can interfere with or be aggravated by exercise. * do not own smartphone for myfitnesspal and centrepoint apps. * lack of an internet connection

Keywords: exercise training insulin resistance lipids arterial stiffness fitness weight maintenance body composition energy expenditure weight loss