Keto Diet Is Best Diet To Lose Weight Fast But Among Worst For Health

Experts have determined that the high-fat, low-carb keto diet is the best diet for short-term weight loss but one of the worst for health.

In the US News & World Report's annual diet rankings released Tuesday, the ketogenic or "keto" diet ranked 20th out of 24 in best diets overall because of its possible long-term health implications due to its restrictive nature.

The yearly report gathers experts in health and nutrition to rank popular diets based on factors such as overall healthiness, easiness to follow, weight loss potential and disease prevention.

The keto diet ranked among the worst with a healthiness score of 1.9 out of 5. It scored 3.9 out of 5 in terms of its fast weight loss rating.

"It is not clear if the keto diet works or is safe in the long term as a weight loss diet," Lana Nasrallah, manager of clinical nutrition at UNC Health in North Carolina, was quoted as saying by US News.

According to the report, a study published in Frontiers in Nutrition in 2021 found that the ketogenic diet may reduce body weight, but it is not more effective in doing so than other diet approaches over the long run when matched with energy intake.

The research also noted that the diet has been linked to an increased risk of chronic kidney disease, cardiovascular disease, cancer, diabetes and Alzheimer's disease due to the decreased intake of the so-called "protective foods," including vegetables, fruits, legumes and whole grains.

The keto diet aims to achieve weight loss by relying mostly on fat instead of sugar or carbohydrates for energy. The diet works by getting the body into ketosis, a state in which the human body breaks down both dietary and stored body fats into substances called ketones.

This makes the keto diet more restrictive, with about 20 net carbs a day or less, to deliberately shift the body into ketosis, the report said.

"Any diet that discourages certain food groups, such as carbs, is not good for long-term weight loss," Lisa D. Ellis, a registered private practice dietitian in New York, said in the report.

Meanwhile, health benefits of the diet include possible short-term weight loss, possible increased satiety and possible reduced need for insulin in people with diabetes, the report noted.

However, the report added that the diet can pose several health risks including brain fog, mood swings, constipation, high cholesterol, kidney and liver problems and nutrient deficiencies.

Pregnant women, children without epilepsy, people with certain types of cancer, people with heart disease and high-performing athletes are discouraged from trying the diet.

"The metabolic needs of these groups are such that they do not align with the macronutrient distribution of the ketogenic diet, which could be potentially harmful or very dangerous, especially if followed over a long period of time," said Lexi Endicott, a registered dietitian and culinary nutrition specialist with To Taste, a culinary nutrition consulting and education company.

But Dr. Mark Cucuzzella, a professor at West Virginia University's School of Medicine who studies low-carb diets, previously told Insider that people don't have to follow the stereotypical "dirty keto" diet full of butter, burgers and cheese.

Examples of healthier keto-friendly foods include fat sources like olive oil, proteins like fish, low-carb fruit like berries, and plenty of leafy greens for nutrients, according to the expert.