Burning Fat with Wild Blueberries in 11 Athletes

This is nearly perfect clickbait that is just about meaningless for an average person in real life. Researchers did a study of fat oxidation after consuming freeze-dried powder from wild blueberries. They found an increased oxidation rate associated with consuming that powder in the 11 aerobically trained males they studied. So the press office at Cal Poly Humboldt, where the researchers work, issued a release saying wild blueberries help with burning fat.  From there, twitter and health reporters take the next leap, writing headlines like “eating wild blueberries can help you lose weight.”

It’s great for wild blueberry sales. For weight loss, not so much.

Small Study, No Weight Loss

To state the obvious, a study of fat oxidation in 11 athletes has little if any relevance to weight loss for someone trying to do something about overweight or obesity. This was a study of metabolic laboratory parameters in a very small sample of males with aerobic fitness training. It tracked fat and carbohydrate oxidation rates during exercise after these subjects had consumed the wild blueberry powder for 14 days.

Fat oxidation went up, carb oxidation went down. But what that means for weight status or for a different group of people is simply unknown. The weight of these subjects did not change and weight outcomes were not the point of this study.

Fat Burning: Sounds Great, Means Less

For someone concerned about their body weight, burning fat sounds like a good thing. Dietary supplement shelves are chock-full of “fat burners.” Gyms and trainers promise to help you burn fat. Poof! problem solved.

But the truth is that losing weight or overcoming obesity is not a simple matter of burning fat. The rhetoric can be quite misleading, as Scott Douglas pointed out in the Washington Post:

“If the key determinant of weight loss were the percentage of fat you’re burning, then your best bet would be to remain still, because that’s when you’re burning the highest percentage of fat relative to carbohydrates.”

In fact, a long-term study of patients trying to maintain weight loss after a lifestyle intervention suggests that fat oxidation rates may be irrelevant to weight outcomes. Sune Dandanell and colleagues found no difference in maximal fat oxidation between persons who regained the weight they had lost and those who kept it off.

So no. Research does not tell us that eating wild blueberries will have us burning more fat and losing weight. If only it were that simple. But both fat metabolism and the physiology of weight regulation are much more complex than peddlers of stories about fat burning want you to believe.

Tim Caulfield is right about this one. We love blueberries, but not hype-filled press releases.

Click here for the study of burning fat with wild blueberries in the form of freeze-dried powder. For the Dandanell study of fat oxidation and weight maintenance, click here. Finally, you can find the commentary by Scott Douglass here.

Serviceberries Are Not Blueberries, photograph by Ted Kyle

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April 8, 2023