Effects of CLA Supplements on Body Weight and Fat Oxidation

University of Wisconsin (UW)

Status and phase: Completed; Phase 2

Conditions: Obesity

Treatments: Drug: conjugated linoleic acid

Study type: Interventional

Funder types: Other

Identifiers

NCT00204932

2004-0060

Details and patient eligibility

About

Conjugated linoleic acid (CLA) is form of fat found in dairy foods, beef and other natural sources. When given to small animals, decreases of body fat have been noted.. Although weight loss is the best treatment for overweight and obesity, it is difficult to maintain the loss in the long term. Because of this, treatment emphasis has turned to small weight losses obtained through non-restrictive diets and prevention of weight regain. This is a study to determine if 6 months of consumption a purified form of CLA will result in greater loss of body fat than control and to determine whether CLA consumption increases total fat oxidation, which would help explain why the weight loss occurs.

Full description

Subjects were screened and then underwent baseline evaluation. The substudy evaluation measured 24-h energy expenditure and substrate utilization by using a whole-room indirect calorimeter. Dietary fat oxidation was measured by mixing [1-13C]oleate and D31-palmitate into a breakfast meal and then collecting breath carbon dioxide and urine to measure the end products of oxidation. Subjects were then provided either 4 g/d of 78% active CLA isomers (3.2 g/d: 39.2% cis-9,trans-11 and 38.5% trans-10,cis-12) or 4 g/d of safflower oil placebo as 1-g gel capsule supplements. The baseline evaluations were repeated 6 mo later.

Enrollment: 53 patients

Sex: All

Ages: 18 to 44 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• BMI 25-29.9 kg/m2
• Absence of a weight change of greater than 3 kg in the previous 6 months

Exclusion criteria

• Presence of a physical limitation to walking exercise
• Current or recent (6 months) enrollment in a commercial or self-prescribed weight loss program
• A history of metabolic disease-ie. renal, endocrine, hepatic or gastrointestinal disease that would impact the outcome of the study
• A history of a psychiatric or eating disorders Ÿ Presence of metal implants that would interfere with body composition analysis
• Fasting plasma cholesterol >300mg/dl or triglycerides above 500 mg/dl.
• Abnormal EKG

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Quadruple Blind

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53 participants in 2 patient groups, including a placebo group

CLA treatment

Active Comparator group

Description:

The group randomized to Conjugated Linoleic Acid (CLA) treatment at 4 grams per day of 39% cis-9, trans-11 CLA; 39% trans-10, cis-12 CLA; and 22% safflower oil for 6 months

Treatment:

Drug: conjugated linoleic acid

Placebo

Placebo Comparator group

Description:

The group randomized to control received 4 g/d of safflower oil.

Treatment:

Drug: conjugated linoleic acid