Effects of CLA Supplements on Body Weight and Fat Oxidation

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.

Study Overview

• Status: Completed
• Conditions: Obesity
• Intervention / Treatment: Drug: conjugated linoleic acid

Detailed 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.

• Study Type: Interventional
• Enrollment (Actual): 53
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • Wisconsin
    • Madison, Wisconsin, United States, 53706
      • University of Wisconsin

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 44 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Quadruple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: CLA treatment; 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	Drug: conjugated linoleic acid; 4 grams per day of 39% cis-9, trans-11 CLA; 39% trans-10, cis-12 CLA, and 22% safflower oil for 6 months
Placebo Comparator: Placebo; The group randomized to control received 4 g/d of safflower oil.	Drug: conjugated linoleic acid; 4 grams per day of 39% cis-9, trans-11 CLA; 39% trans-10, cis-12 CLA, and 22% safflower oil for 6 months

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fat Mass	loss of fat mass, kg	6 months

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Total Fat Oxidation	24 hour respiratory gas analysis	6 months

Collaborators and Investigators

• Sponsor: University of Wisconsin, Madison
• Investigators: Principal Investigator: Dale A Schoeller, PhD, University of Wisconsin, Madison; Study Chair: Dale A Schoeller, PhD, University of Wisconsin, Madison

Publications and helpful links

General Publications

• Watras AC, Buchholz AC, Close RN, Zhang Z, Schoeller DA. The role of conjugated linoleic acid in reducing body fat and preventing holiday weight gain. Int J Obes (Lond). 2007 Mar;31(3):481-7. doi: 10.1038/sj.ijo.0803437. Epub 2006 Aug 22.
• Close RN, Schoeller DA, Watras AC, Nora EH. Conjugated linoleic acid supplementation alters the 6-mo change in fat oxidation during sleep. Am J Clin Nutr. 2007 Sep;86(3):797-804. doi: 10.1093/ajcn/86.3.797.

Study record dates

Study Major Dates

• Study Start: July 1, 2004
• Primary Completion (Actual): March 1, 2005
• Study Completion (Actual): March 1, 2005

Study Registration Dates

• First Submitted: September 12, 2005
• First Submitted That Met QC Criteria: September 13, 2005
• First Posted (Estimate): September 20, 2005

Study Record Updates

• Last Update Posted (Actual): July 17, 2018
• Last Update Submitted That Met QC Criteria: June 18, 2018
• Last Verified: June 1, 2018

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Body Weight
• Other Study ID Numbers: 2004-0060