Metabolically Normal and Metabolically Abnormal Obesity

The purpose of this study is to learn more about why some obese persons are resistant to developing obesity-related metabolic diseases (such as diabetes and cardiovascular disease), while others are prone to developing these conditions. We will do this by studying obese persons before and after a 5% body weight gain. Subjects will be asked to increase their current diet for a period of 8-12 weeks in order to increase their current body weight by 5%. Each will then be asked to maintain this weight increase for 3 weeks. We will monitor subjects throughout this time period with weekly medical evaluations. At the completion of the study, we will provide each subject with a 6-month weight loss program.

Subjects in this group are metabolically normal. They have low liver fat defined as less than five percent as determined by magnetic resonance spectroscopy. Intervention: Subjects will begin an 8-12 week high-calorie diet intervention. They will eat an additional 1000 kcal/day for two to three months, until a moderate, approximately 5% weight gain is achieved. The recommended dietary energy intake will be 1000 kcal/d more than the subject's baseline resting energy expenditure. An individualized diet plan will be developed for each subject by the study dietitian based on estimated energy requirements, and the subject's food preferences and dietary habits.

Subjects in this group are metabolically abnormal. They have high liver fat defined as at least ten percent as determined by magnetic resonance spectroscopy. Intervention: Subjects will begin an 8-12 week high-calorie diet intervention. They will eat an additional 1000 kcal/day for two to three months, until a moderate, approximately 5% weight gain is achieved. The recommended dietary energy intake will be 1000 kcal/d more than the subject's baseline resting energy expenditure. An individualized diet plan will be developed for each subject by the study dietitian based on estimated energy requirements, and the subject's food preferences and dietary habits.

Subjects will begin an 8-12 week high-calorie diet intervention. They will eat an additional 1000 kcal/day for two to three months, until a moderate, approximately 5% weight gain is achieved. The recommended dietary energy intake will be 1000 kcal/d more than the subject's baseline resting energy expenditure. An individualized diet plan will be developed for each subject by the study dietitian based on estimated energy requirements, and the subject's food preferences and dietary habits.

Inclusion Criteria: Obese subjects (BMI 30.0 - 39.9 kg/m2) Sedentary subjects (exercise less than 1 hr/wk) Exclusion Criteria: Pregnant or lactating women Michigan Alcohol Screening Test score ≥4 Active or previous history of liver disease Active or previous history of diabetes history of alcohol abuse, or currently consuming ≥20 g alcohol/day Severe hypertriglyceridemia (>300 mg/dL) Smoke tobacco Take medication that might confound the study results

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Fabbrini E, Yoshino J, Yoshino M, Magkos F, Tiemann Luecking C, Samovski D, Fraterrigo G, Okunade AL, Patterson BW, Klein S. Metabolically normal obese people are protected from adverse effects following weight gain. J Clin Invest. 2015 Feb;125(2):787-95. doi: 10.1172/JCI78425. Epub 2015 Jan 2.