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Protocol Details

Dietary Linoleic Acid Regulation of Omega-3HUFA Metabolism: Satiety and Body Composition Among Overweight Female Subjects

This study is currently recruiting participants.

Summary | Eligibility | Citations | Contacts




Sponsoring Institute

National Institute on Alcohol Abuse and Alcoholism (NIAAA)

Recruitment Detail

Type: Participants currently recruited/enrolled
Gender: Female
Min Age: 18
Max Age: 50

Referral Letter Required


Population Exclusion(s)


Special Instructions

Currently Not Provided


Omega-3 Fatty Acids

Recruitment Keyword(s)



Weight Gain;
Healthy Subjects;

Investigational Drug(s)


Investigational Device(s)



Dietary Supplement: Linoleic Acid
Dietary Supplement: Docosahexaenoic Acid
Dietary Supplement: Eicosapentaenoic Acid

Supporting Site

National Institute on Alcohol Abuse and Alcoholism


- Rates of obesity have increased dramatically in recent decades, and researchers are investigating how changes in diets and physical activity have contributed to this increase. To understand how weight might be controlled, it is important to learn what kinds of dietary changes can affect hunger and might lower body weight. Essential fatty acids, for instance, are an important part of a healthy diet, but researchers have not yet determined the ideal amount of essential fatty acids that people should eat. By studying how different diets affect body chemistry and hormone levels in women who are overweight or obese, researchers hope to be able to determine better diets or treatments to help people reach and maintain an optimum healthy weight.


- To examine how certain fats in the diet affect body metabolism, hormones, and weight regulation.


- Healthy women between 18 and 50 years of age who are overweight or obese (body mass index between 25 and 35).


- This study has an initial screening visit and three phases. All participants will be involved in the first two phases of the study, and some participants will be involved in the third phase.

- Participants will be screened with a physical examination and medical history, in addition to blood and urine tests and questionnaires about eating habits and other diet factors.

- Phase 1: Participants will have three visits to the National Institutes of Health over a 4-week period. At the visits, participants will have blood and urine tests, complete questionnaires, and have other tests including brain and body imaging studies. Participants will then be assigned to one of three study diets.

- Phase 2: Participants will have a 12-week diet phase, with all foods supplied by the study researchers. Participants will keep a daily log of food and beverage intake, and will have three testing sessions with procedures similar to those performed in Phase 1.

- Phase 3: Participants assigned to a particular study diet (one-third of all participants) will be given the option of continuing the diet for an additional 36 weeks (9 months), with food consumption, monitoring, and testing procedures similar to those performed in Phase 2.

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Subjects will be overweight, but otherwise healthy, pre-menopausal ambulatory volunteers aged 18 to 50.

To be eligible for this research study, participants must:

-Be between 18 and 50 years of age.

-Have regular menstrual cycles.

-Be willing to use an effective method of birth control such as hormonal contraception, intrauterine device, barrier methods combined with spermicide, or surgical sterilization.

-Have a body mass index of 25 to 35 kg/m(2).

-Be otherwise healthy as determined by history, medical examination and laboratory tests.

-Be able to come to the NIH Clinical Center every weekday for 3 months.

-Be able to understand the consent form, and provide informed written consent.


Participants are not eligible for this research study if they:

-Have been pregnant or have breast fed within the last 2 years.

-Work, or have an immediate family member who works, with a study investigator. Immediate family is defined as a spouse, parent, child or sibling, whether biological or legally adopted.

-Are HIV positive.<TAB>

-Have any current, unstable medical conditions including respiratory insufficiency requiring oxygen therapy; cardiac ischemia; cardiac or hepatic failure; or acute neurological illness as assessed by history and physical exam.

-Have evidence of diseases that may influence metabolism (e.g. overt diabetes mellitus, thyroid disease, cancer)

-Have any current or past history of eating disorders such as binge eating or anorexia nervosa.

-Have had weight loss (bariatric) surgery.

-Have gained or lost more than 3% of your current weight in the past 3 months.

-Exercise strenuously, like running, swimming, or basketball, 4 or more times per week.

-Are planning to begin a strenuous exercise program in the next 4 months.

-Take supplements that contain omega-6 or omega-3 fatty acids (e.g. fish, cod liver, borage, evening primrose oils)

-Have significant dietary limitations (e.g. multiple food allergies/intolerances, vegan diet) or special dietary requirements that are difficult to accommodate with study diets

-Have significant claustrophobia that would preclude study tests.

-Have a history of alcohol or substance abuse or dependence in the past 5 years.

-Drink more than 2 alcoholic beverages per day, on average, or 6 drinks per sitting in the past year. Participants may drink up to one alcoholic beverage per day during the study.

-Used marijuana, amphetamines, cocaine, or heroin even once over the last year. Participants may not use marijuana, amphetamines, cocaine, or heroin during the study.

-Have smoked 2 or more cigarettes per week, on average, over the past year.

-Participants may not use tobacco products during the study.

-Eat fish 3 or more times per week on average.

-Have a known bleeding disorder.

-Take medications or supplements that may interfere with this study by altering energy metabolism, nutrient absorption, or food intake. Regular use of the following compounds warrants exclusion: medications for the management of diabetes (Type 1 or 2), typical and atypical antipsychotics, thyroid medications, glucocorticoids, orlistat, decongestants, anti-histamines, and medications for cardiac conditions (e.g beta blockers), attention disorders (e.g. amphetamine derivatives), blood lipid disorders (e.g. statins, fibrates), and hypertension (e.g. thiazide diuretics), as well as certain anti-depressants (e.g. tricyclics), and supplements that impact energy metabolism, such as ephedrine.

-Regularly take an anticoagulant medication, such as warfarin or aspirin.

-Have a pacemaker, brain stimulator, or other implanted electrical device, permanent eyeliner, metallic prosthesis (including metal pins and rods, heart valves, and cochlear implants) that would preclude MRI scans.

-Are currently participating in any other clinical research studies that include blood draws or other procedures.

-Have a serum FSH level greater than 20 units per liter

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Cota D. The role of the endocannabinoid system in the regulation of hypothalamic-pituitary-adrenal axis activity. J Neuroendocrinol. 2008 May;20 Suppl 1:35-8.

Pagotto U, Marsicano G, Cota D, Lutz B, Pasquali R. The emerging role of the endocannabinoid system in endocrine regulation and energy balance. Endocr Rev. 2006 Feb;27(1):73-100. Epub 2005 Nov 23.

Szmitko PE, Verma S. The endocannabinoid system and cardiometabolic risk. Atherosclerosis. 2008 Aug;199(2):248-56. Epub 2008 Mar 20.

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Principal Investigator

Referral Contact

For more information:

Christopher E. Ramsden, M.D.
National Institute on Aging (NIA)
BRC BG RM 08C210
(410) 558-8369

Christopher E. Ramsden, M.D.
National Institute on Aging (NIA)
BRC BG RM 08C210
(410) 558-8369

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

Clinical Trials Number:


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