There are lots of different diets out there – and just as many different ways to approach dropping those excess pounds that plague so many of us. One way that’s gained a lot of attention in recent years is the ketogenic, or keto, diet, which has gained a reputation as being a surefire way to drop a lot of weight very quickly.
“Classic keto is a high-fat, adequate protein, low-carbohydrate diet designed to produce ketosis through mimicking the metabolic changes of starvation. Keto diets force the body to use fat as its primary source of energy,” says Cathy Leman, a registered dietitian nutritionist and founder of Dam. Mad. About Breast Cancer, a nutritional consulting firm based in greater Chicago that’s aimed at helping breast cancer patients and survivors.
“This original keto diet is 90% fat, 6% protein and 4% carbohydrate,” Leman explains. Other variations have also cropped up with slightly different ratios of fat, carbs and protein, but the hallmark of the keto diet is that the vast majority of calories are derived from fat, which somewhat counterintuitively seems to lead to rapid weight loss.
“The keto diet fad is definitely having its moment in the limelight,” says Liz Weinandy, a registered dietitian with the Ohio State University Wexner Medical Center. That’s because it’s widely promoted as being a quick-weight-loss option. Given that 71.6% of Americans are overweight and obese, according to the Centers for Disease Control and Prevention, many people are turning to this very restrictive way of eating in a bid to drop some of those excess pounds.
Causes for Weight Gain
For some people, adopting the keto diet can be a quick way to jump-start a weight loss journey. But there’s a catch, Weinandy says. “It does not result in weight loss for everyone, and worse yet, it often causes weight gain.”
That weight gain occurs because the diet is very high in fat, and fat is a calorie-dense macronutrient. A gram of fat contains nine calories. Carbohydrates and protein – the other two macronutrients that make up our diet – contain just four calories per gram.
“Because fat is so much higher in calories, it often means people are taking in more calories than their body needs, and this can cause weight gain,” Weinandy says.
The keto diet also relies on a process called ketosis to result in weight loss. To get into ketosis, you have to “limit and almost eliminate foods with carbohydrates in them,” Weinandy says. This means no sweets, bread, chips and sugary beverages, which are usually good things to avoid or eliminate when you’re trying to eat healthier. But ketosis also demands the removal of healthy carbs, such as “fruits, starchy vegetables, legumes and whole grains,” she says.
If you’re following the diet strictly and achieve ketosis, this can result in weight loss. “Upon going into ketosis, the user will shed weight through the excretion of water from glycogen depletion,” says Matthew Black, a clinical dietitian with the Ohio State University Wexner Medical Center. If you’ve also reduced the overall number of calories you’re consuming, this can lead to a quick weight loss of “more than five pounds in the first week, which sort of ‘fish hooks’ and creates excitement for the keto dieter,” he explains.
However, “the majority of this weight loss is from losing water, which is not a true loss of body weight,” Black says. “Additionally, I often hear patients remark how they ‘gained weight immediately the moment they started eating carbohydrates,’ which further perpetuates the notion that eating carbohydrates will prevent weight loss. The weight gain associated with going out of ketosis (from reintroducing carbohydrates) is a natural and expected consequence.”
This means that weight loss is only achieved when you’re actively following the diet, which can be very difficult to do given how restrictive the keto diet is.
“In addition to potentially leading to weight gain in some individuals, the keto diet can increase LDL cholesterol – that’s the bad kind that you want to reduce rather than elevate,” Weinandy says. “It also increases insulin resistance,” a condition also called prediabetes in which the body can’t absorb insulin correctly and, thus, keeps your blood sugar levels higher than they should be. This situation can develop into Type 2 diabetes. “Heart disease and diabetes are common in the U.S., and the keto diet makes these conditions worse,” she adds.
Because of these risks, Weinandy doesn’t recommend the ketogenic diet to patients looking for weight loss.
“It’s not a good way to lose weight because it cuts out so many foods that we know are important for human health. We have decades of research showing that the healthiest diet is one based on healthy plant-based foods like fruits, vegetables, whole grains and legumes.” To this base, Weinandy recommends adding “lean, unprocessed protein sources – either animal or plant-based to create an ideal diet.”
But there are some patients for whom the ketogenic diet might be the right fit, Weinandy notes. “The ketogenic diet got its start by showing it could help patients with epilepsy have better seizure control. If a patient has multiple seizures that medications, surgery or other conventional medical treatments cannot help control, the keto diet can be a blessing and improve their quality of life.”
In fact, for some people with very severe epilepsy, switching to the ketogenic diet can reduce their experience of seizures from several each day to just a few a week. And the diet can also reduce the intensity of those seizures that still occur.
But this is a very specific type of patient, and for most people, Weinandy says, “the risk of following a keto diet would be lower than the benefit. We have to look at this risk to benefit ratio and think about what is best for our overall health and quality of life.”
The Most Effective Way to Lose Weight
If you’re looking to lose weight, try these approaches instead:
- Reduce your consumption of unhealthy carbohydrates, such as desserts, snacks, chips and sugary beverages. “For people who lose weight on the keto diet, it is usually from cutting out the junk foods. How about starting with reducing these high-calorie junk foods, and see how that goes?” Weinandy asks.
- Add more fruits and a wide variety of vegetables. “Unprocessed plant foods like fruits and vegetables have so many nutrients in them that help lower the risk of many diseases, including heart disease and many types of cancer,” Weinandy says.
- Add regular physical activity. Moving more can help you burn calories and may help control appetite. Regular exercise also pays huge dividends for your cardiovascular and overall health.
- Add a practice of being mindful about food. Think about what you’re eating and savor each bite. Stop eating in front of the television or your computer, and instead, focus on the meal in front of you. This can help curb overeating or mindless eating.
- Have patience. “The ketogenic diet causes rapid weight loss by driving water out of the body,” Weinandy says, but this isn’t what dieters actually want. “They want to lose extra body fat,” and that takes time. However, if you put new healthy habits into place and give your body time, you’ll eventually get there. “We don’t have to do something extreme like keto to lose weight and be healthy.”