The ketogenic diet is is enjoying a surge of popularity these days and for good reason. Going “keto” can help you tap into your body’s stored fat—up to 100,000 calories of readily available energy—allowing you to push longer and harder during training without constantly refueling. Of course, this comes at a price: You have to eradicate nearly all carbohydrates from your diet and subsist on fats—they should make up 70 to 80 percent of what you eat—and protein. Making the metabolic shift to full fat-burning mode can take three to six weeks.
That’s a tall order. So the performance nutrition market has responded with a short- cut: ketogenic supplements. They come in powders, capsules, chews, meal replacements, and even coffee creamer and claim to help you immediately burn more fat, shed pounds, and perform better—without giving up bread.
Those are some incredible benefits. But look past the promises and the science unravels.
Keto supplements claim they can trick your metabolism into thinking it’s carb deprived and send it into ketosis. This could be an evolutionary adaptation the human body created to survive famine. Lisa Sasson, a nutritionist at New York University, explains that during ketosis, the liver begins to break down fatty acids, sending ketone compounds into the bloodstream, which can be used to fuel muscles.
Hypothetically, taking supplements with synthetic ketones would move the body into ketosis in minutes and last a couple of hours, says Brendan Egan, an associate professor of sports and exercise physiology at Dublin City University. But that doesn’t mean you’ll suddenly be able to power through burpees or run for miles without stopping. Of the few reports done on commercially available ketone supplements, some suggest only a negligible performance improvement while others actually found a reduction.
As for the supplements’ weight-loss guarantees, here again, don’t be fooled. “The fat-burning idea seems to be conflating the effects of a ketogenic diet with the effects of ketones themselves,” says Egan. In other words, the only way to get the fat-burning benefits of a ketogenic diet is by actually stick- ing to the diet. Downing a ketone pill or powdered shake and continuing to eat whatever you want won’t magically lean you out. But we’re guessing your gut—whether it’s thick or thin—told you that already.