Frustrated dieters who can’t lose weight are turning to a new option – the ketogenic diet – in hopes of shedding pounds.
On this low-carb diet, you dramatically reduce intake of carbohydrates in an attempt to force your body into ketosis. Molecules known as “ketones” build up in the bloodstream, blood sugar levels drop and your body begins to break down fat as a source of energy.
Three experts associated with the Academy of Nutrition and Dietetics acknowledge that many people lose weight on the ketogenic diet.
“People who go on the ketogenic diet often report large amounts of weight loss in a short period of time,” says Alissa Rumsey, a New York-based registered dietitian and certified strength and conditioning coach.
However, the experts also caution that the weight loss is not likely to endure – and that there are better ways to slim down.
Why people on the keto diet lose weight
Proponents of the keto diet say it causes weight loss because it forces your body to burn fat for energy. But Rumsey says water weight accounts for much of the weight lost in the keto diet.
“Carbohydrates hold onto water in the body,” she says. “So if you cut out carbohydrates, you end up losing that water weight.”
In addition, people on the ketogenic diet typically burn more calories than they take in, says Caroline West Passerrello, registered dietitian nutritionist and immediate past president of the Pittsburgh Academy of Nutrition and Dietetics.
Thanks to the diet’s high fat content, you are also more likely to feel full and “satisfied” on the diet. “When someone is satisfied – mentally, physically and emotionally – they may eat less,” Passerrello says.
However, the diet can have side effects. Some people report mental fogginess and constipation, says Jessica Crandall, a registered dietitian nutritionist with Denver Wellness & Nutrition.
It also can be tough to eat a ketogenic-friendly meal in social situations, such as at restaurants and parties, she adds.
In addition, all three experts agree that it can be extremely difficult to maintain the ketogenic diet over the long haul.
“Most people have to eat less than 30 to 40 grams of carbohydrate per day in order to start ketosis and keep it going,” Rumsey says. “This roughly equates to about 5 percent of overall calories. The bulk of the diet is made up of fat calories, which is tough to do.”
Better alternatives to the keto diet
None of the experts recommends the keto diet as an effective method of losing weight – and keeping the pounds off.
“The ketogenic diet drastically limits the carbohydrates you eat, resulting in water loss,” Passerrello says. “Start eating carbohydrates again, and the water and weight follow right along.”
Instead, they suggest different methods of staying slim. Crandall recommends a three-tiered approach to losing weight that incorporates:
- Increased activity levels
- Decreased intake of some carbohydrates, especially added sugars
- Eating smaller portions. “You don’t need to overfuel your body,” she says.
Overall, she argues for a more balanced approach to dieting, rather than going to extremes. “We don’t need to have this ‘black and white’ approach,” she says.
Passerrello says a registered dietitian can craft successful weight loss strategies, which typically combine dietary and behavioral modifications. “The specific combination is different for everyone,” she says.
If you are going to try the ketogenic diet, Rumsey recommends caution, and urges you to give your body time to adapt to the change.
“Very low-carb diets are not for everyone, and it’s important to listen to your body,” she says. “If after a few weeks you feel worse than before, then you should stop and reconsider if it is the right diet for you.”