Is the Keto Diet Good or Bad? We Weigh the Pros and Cons

If you've struggled with disordered eating in the past, the keto diet is probably not the best option for you, said Lisa Samuels, RD, founder of The Happie House. "It's restrictive in nature and eliminates entire food groups from the diet. For those with disordered eating patterns, it's important to emphasize that all foods are safe and can fit into a healthy diet," Samuels adds.

Even if you don't have a history of disordered eating, Samuels said the diet is too focused on weight loss rather than overall health. "Cutting a food group out entirely, in this case carbohydrates, is only increasing the risk of developing complications later such as cardiovascular disease and kidney stones," she notes.

The keto diet is so popular because countless people have lost weight on it, like @fat2fitdreaj. She lost over 100 pounds on the keto diet and told the Instagram account @keto.fit.usa, "This lifestyle change was the best decision I've ever made. I never want to be over 300lbs again! There's no stopping me."

Check out our gallery of 18 before-and-after photos that show how effective the keto diet can be for losing weight.

Since the keto diet is so low in carbs, many people cut carbs by cutting out whole grains and fruit. Even though fruit contains sugar and should be eaten in moderation (i.e., you shouldn't have 17 bananas a day), it's still an excellent source of fiber, vitamins, and minerals. And if you're more focused on eating fats and protein, you may neglect eating the daily recommended amount of veggies and skip out on those important nutrients.

"You may end up with a diet that's deficient in some vitamins and minerals," says Katherine Brooking, MS, RD, cofounder of Appetite For Health.

Since the keto diet is so low in carbohydrates and therefore low in sugar, it may be effective in regulating blood sugar and treating type 2 diabetes when done carefully under medical supervision.

Steve Phinney, MD, PhD, chief medical officer at Virta Health, tells POPSUGAR that the keto diet could help regulate blood sugar. "Type 2 diabetes is a disease characterized by high blood sugar, meaning it can also be thought of a disease of carbohydrate intolerance," he says. "By cutting out most dietary carbohydrates and replacing them with a well-formulated ketogenic diet, people living with type 2 diabetes are able to reduce and maintain their blood sugar closer to or actually in the normal range."

Because the keto diet is so high in fat, you may end up eating too much saturated fat from bacon, butter, cheese, and fatty meats, which could negatively impact your cholesterol levels. "You may see your cholesterol levels skyrocket, as all of these [foods] are high in saturated fat, which is known to increase unhealthy LDL cholesterol," Brooking tells POPSUGAR.

Amnon Beniaminovitz, MD of the Medical Offices of Manhattan, adds that this is particularly problematic for people who have heart disease risk factors. If you want to try the keto diet, Dr. Beniaminovitz advises, "You should have your cholesterol checked routinely and be followed by a cardiologist or an endocrinologist that can modify the diet and help minimize the risks."

Sure, the keto diet can help you lose weight, but that's not the only way it targets belly fat. Dr. Phinney told POPSUGAR that it can help fight inflammation.

"A well-formulated ketogenic diet has potent anti-inflammatory effects throughout the body, including for belly fat, and thus enables a person to lose it," he says. Curbing chronic inflammation can also help you ease joint pain, digestive issues, fatigue, and skin issues.

"While a ketogenic diet has been shown to decrease appetite while burning fat and maintaining muscle, it is not without risk," says Holly Pudwill, president and clinical dietitian at Balanced Nutrition of Jacksonville. "Ketones are a byproduct of ketosis. If those build up, a condition called ketoacidosis can result." When this happens, ketones build up in the blood, making it too acidic and causing dehydration.

Cardiologist Luiza Petre, MD, told POPSUGAR that the keto diet can help lower blood pressure, albeit not directly. Since obese individuals have a greater chance of developing high blood pressure, she says, losing weight with the keto diet could lower your risk.

"The bottom line is the ketogenic diet will improve blood pressure, but not as a direct effect; it's through its indirect weight-loss benefits," she says. "If the keto diet is done without a weight-loss goal, basically on a high-fat diet without a calorie deficit, it might not impact blood pressure at all. Losing weight remains the number-one intervention followed by lowering salt and exercising to improve blood pressure."

"Typically, the body's main source of energy comes from glucose, which is a sugar that is metabolized from the digestion of carbohydrates," says Lorraine Kearney, holistic nutritionist. Glucose is the main source of fuel for the brain, nervous system, red blood cells, and certain bodily tissues — and carbohydrates are a key source of glucose.

"Without adequate glucose sources in the diet, the body must change the way it burns energy so that it can function. Low-carb, high-fat, and high-protein diets cause a shift in glucose metabolism and the body begins to rely on partially broken-down products of fat, called ketone bodies, as fuel," Kearney explains. "If just the right amount of calories from carbohydrates are consumed, the body prevents the breaking down of protein into amino acids for energy (i.e., ketones) to maintain optimum functioning of vital organs, such as the liver and kidneys."

However, people on the keto diet run the risk of not having enough glucose in their bodies due to the diet's restriction of carbohydrates. When this happens, Kearney says that the body will begin to take protein from the muscles. "This will decrease the building, repair, and functioning of the body and its vital organs, such as the heart, lungs, liver, and kidneys," she explains.

The keto diet is a popular diet at the moment, but its effectiveness and the long-term implications of eating this way depend person to person. How well it may work for someone depends on his or her goals, lifestyle, and eating habits. If you are interested in trying the keto diet for yourself, it's best to consult your doctor or a registered dietitian. You can also seek out a place that specializes in the keto diet, such as Virta Health.