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[At one year following a major weight loss, control subjects taking olive oil in a randomized controlled double-blinded study had regained more than four times as much weight as the subjects supplemented with GLA (borage oil). The controls regained an average of 16.7 pounds plus/minus 4.6 pounds, versus a gain of only 4 pounds plus/minus 3.5 pounds for the subjects taking borage oil.]

Journal: Journal of Nutrition. 2007 Jun;137(6):1430-5

Authors and affiliation: Schirmer MA, Phinney, SD. Department of Nutrition, University of California, Davis, California. [E-Mail: sdphtb@comcast.net ]

PMID: 17513402

The purpose of this study was to determine whether gamma-linolenate (GLA) supplementation would suppress weight regain following major weight loss.

Fifty formerly obese humans were randomized into a double-blind study and given either 890 mg per day of GLA (5 g per day borage oil) or 5 g per day olive oil (controls) for 1 year.

Body weight and composition and adipose fatty acids of fasting subjects were assessed at 0, 3, 12, and 33 months.

After 12 subjects in each group had completed 1 year of supplementation, weight regain differed between the GLA (2.17 +/- 1.78 kg) and control (8.78 +/- 2.78 kg) groups (P < 0.03). The initial study was terminated, and all remaining subjects were assessed over a 6-wk period.

Unblinding revealed weight regains of 1.8 +/- 1.6 kg in the GLA group and 7.6 +/- 2.1 kg in controls for the 13 and 17 subjects, respectively, who completed a minimum of 50 weeks in the study.

Weight regain did not differ in the remaining 10 GLA and 5 control subjects who completed < 50 weeks in the study.

In a follow-up study, a subgroup from both the original GLA (GLA-GLA, n = 9) and the original control (Control-GLA, n = 14) populations either continued or crossed over to GLA supplementation for an additional 21 months. Interim weight regains between 15 and 33 months were 6.48 +/- 1.79 kg and 6.04 +/- 2.52 kg for the GLA-GLA and Control-GLA groups, respectively.

Adipose triglyceride GLA levels increased 152% (P < 0.0001) in the GLA group at 12 months, but did not increase further after 33 months of GLA administration.

In conclusion, GLA reduced weight regain in humans following major weight loss, suggesting a role for essential fatty acids in fuel partitioning in humans prone to obesity. [Fuel partitioning involves where and how metabolic fuels are utilized. This may generate signals the brain uses to control food intake.]