Protocol Number: 09-DK-0238

Title:

Diet-Induced-Obesity Resistant Phenotypes in Humans

Number:

09-DK-0238

Summary:

Background:

- Obesity is the result of many factors, including genetics and lifestyle, such as over-eating high-calorie foods and not being physically active. Obesity affects approximately one third of adults in the United States. Researchers often study individuals who are already overweight and obese, but another approach is to examine people who stay thin despite eating whatever they want and not exercising. Studying these thin individuals will enhance understanding of why some people become obese and others do not, which may lead to novel treatments for obesity.

Objective:

- To study the metabolism, body composition, body temperature, physical activity, and blood chemistries of healthy lean adults before and after adding 1,000 extra Calories per day to their normal diet.

Eligibility:

- Healthy adults, 30 to 50 years of age, who have never been overweight after adolescence, who are currently weight-stable, sedentary, and eating without restrictions.

Design:

- The entire study will take about 9 weeks and will include the following outpatient and inpatient visits:

- Outpatient screening visit and monitoring: Physical examination and blood test at screening; then, one week of physical activity monitoring (e.g., with a pedometer-like device called an accelerometer) and completing a food diary.

- Baseline inpatient visit (5 days): Volunteers will eat a normal diet to maintain body weight. Energy expenditure, body composition, physical fitness, activity level, and eating behavior will be measured. Urine and blood samples will be taken. Volunteers may go home for the weekend or stay at the metabolic clinical research unit (MCRU).

- Inpatient feeding week 1 (5 days): Volunteers will eat a normal diet plus milkshakes for added calories. All the same measurements during the baseline week visit will be repeated.

- Outpatient feeding weeks 2-3: Volunteers will eat breakfast at the MCRU everyday for the next 2 weeks and take prepared meals home with them (volunteers may also stay at the MCRU for the 2 weeks if they prefer). Volunteers will drink a non-radioactive (heavy) water called doubly labeled water to measure energy expenditure in their normal living environment Daily urine samples will be collected.

- Inpatient feeding week 4 (5 days): Volunteers will continue eating a normal diet plus milkshakes for added calories. This stay and measurement is identical to inpatient feeding week 1.

- Volunteers will be contacted at 6 and 12 months to assess any changes in body weight, diet, and physical activity.

Sponsoring Institute:

National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

Recruitment Detail

Type: Participants currently recruited/enrolled

Gender: Male & Female

Referral Letter Required: No

Population Exclusion(s): Children

Eligibility Criteria:

INCLUSION CRITERIA:

1. Healthy normal men and women between 30-50 years of age;

2. BMI between 18.5 and 23.0 kg/M(2);

3. Self-reported as having had trouble gaining weight, who doing little or no exercise, self-described or by friends or family members as an overeater, and who have never tried to lose weight.

EXCLUSION CRITERIA:

1. A self-reported history of overweight after the age of 18, other than during pregnancy for women;

2. Recent weight changes > 2% of current body weight in the last 6 months;

3. Current or past history of eating disorders such as binge eating, anorexia nervosa, or bulimia, by psychological evaluations;

4. Current or past history of intentional weight loss by self-report, other than postpartum weight loss;

5. High physically demanding occupations or volitional exercise > 20 total minutes/day of moderate intensity or higher (as measured by sweating), > 2 days/week, by self-report;

6. Significant dietary limitations (multiple food allergies/intolerances, vegan diet, etc.) that may affect absorption and body weight, or special dietary requirements that are difficult to accommodate with by study diets;

7. Significant physical limitations that may preclude completing the majority of the tests in this study;

8. Current pregnancy, recent pregnancy (< 3 years), current/recent breast feeding (< 1 year), or perimenopausal status. During the study, women may be asked to use birth control and will undergo repeated pregnancy testing. Subjects who refuse these tests will be excluded;

9. Current or past medical conditions that are known to affect energy metabolism and body weight regulations, including HIV/AIDS, cancer, cardiac ischemia, dyslipidemia, thyroid and parathyroid disorders, hypo- or hypertension, diabetes (type 1 or type 2) or impaired glucose tolerance, congenital or acquired lipodystrophy, hepatic, renal, neuromuscular, celiac disease and other malabsorptive conditions, known genetic disorders that alter lipid metabolism, or cardiac failure as assessed by history and physical exam;

10. Any psychiatric condition (including psychosis) or personality disorder as judged by the PI or Co-PI that would impede participation in the study;

11. Smoking (currently or within the past year), excessive caffeine (> 500 mg/day) and/or alcohol intake (> 2 drinks/day for men, > 1 drink/day for women), as assessed by self reports;

12. Any use of medications or nutritional supplements known to increase EE, depress food intake, or affect absorption;

13. Unwilling or unable to give informed consent;

14. Any other clinical or sub-clinical conditions not mentioned above that are considered by the investigators as significant exclusions for the study.

Special Instructions:

Currently Not Provided

Keywords:

Energy Expenditure

Dietary Intake

Physical Activity

Body Weight Regulation

Sedentary

Recruitment Keyword(s):

HV

Healthy Volunteer

Condition(s):

Healthy Volunteers

Investigational Drug(s):

None

Investigational Device(s):

None

Intervention(s):

None

Supporting Site:

National Institute of Diabetes and Digestive and Kidney Diseases

Contact(s):

Patient Recruitment and Public Liaison Office
Building 61
10 Cloister Court
Bethesda, Maryland 20892-4754
Toll Free: 1-800-411-1222
TTY: 301-594-9774 (local),1-866-411-1010 (toll free)
Fax: 301-480-9793

Electronic Mail:prpl@mail.cc.nih.gov

Citation(s):

Ogden CL, Carroll MD, Curtin LR, McDowell MA, Tabak CJ, Flegal KM. Prevalence of overweight and obesity in the United States, 1999-2004. JAMA. 2006 Apr 5;295(13):1549-55.

Comuzzie AG, Allison DB. The search for human obesity genes. Science. 1998 May 29;280(5368):1374-7.

Coleman DL. Obesity genes: beneficial effects in heterozygous mice. Science. 1979 Feb 16;203(4381):663-5.

• Questions about participating in a study, please contact the Patient Recruitment and Public Liaison Office, CC.
• Technical questions regarding the Clinical Center web site, please contact the Department of Clinical Research Informatics, CC.

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