Monday, December 25, 2006

CLA - Far from a Magic Weight Loss Bullet

The media are alive with the sound of CLA!

I can't get over the number of articles I've read, in both mainstream and blogosphere press, about the benefits of supplementation with CLA (conjugated linoleic acid) on body weight and body fat percentage, and all from a very small, limited, and poorly designed study.

The study took 40 (yes, just 40) people and randomly assigned 20 to receive a CLA supplement and 20 to a placebo for a 6 month period. The subjects were exclusively young (between the ages of 18 and 44) and none of them were obese to begin with (BMI between 25 and 30). They were watched to see if there was a difference in weight loss and/or a difference in their body fat percentage.

The study was written in a manner that was supposed to reflect "holiday weight gain" by being conducted over the course of last year's Christmas holiday season. That said, while the study participants were indeed controlled so that the placebo and control groups were roughly the same age and weight, what was not controlled for was lifestyle.

What do I mean by that? Well, there's no note about whether or not the participants used gyms, whether or not they had sedentary or active jobs and importantly, given the aim to discuss "Holiday" weight gain, their religions, whether or not they had large family gatherings over the holiday season and whether or not they themselves celebrated a holiday season were not mentioned in the methodology or controls.

Regardless, even if we ignore the clear lack of appropriate controls, the results were far from spectacular.

With a percentage just barely greater than would happen by chance, the folks in the CLA group lost a grand total of 1.3lbs and their body fat percentage went down by 1%.

So what can we conclude from this paper?

Not too much.

Best case conclusion:

If you're a non-obese, young adult and you want to spend over $20 a month on CLA supplements, you may lose 1.3lbs over a 6 month period.

Wanna know how else you could lose 1.3lbs over a 6 month period?

Burn or not eat 25 calories a day.

Hmmm, let's see, $120 in pills that may have long term risk (in multiple studies CLA has been shown to increase insulin resistance and increase deposition of fat in the liver and spleen) or you could simply walk for an extra 5 minutes every day.

As I tell all my patients, if there was something that I could sell them that would help them lose weight and help me pay the rent, I would.

Guess I'm the scrooge of supplements 'cause I don't sell any!

Merry Christmas to all those celebrating, and a big Bah-Humbug to the neutraceutical corporations and the press who get folks excited about non-exciting stuff!