The researchers monitored the participants’ weight, blood sugar (glucose) levels, cardiovascular risk factors and diet adherence. Which diet was still at the last bell? “Both diets improved blood glucose control to a similar extent, and both groups lost a similar amount of weight,” said lead nutrition researcher Dr. Walter Willett, professor of epidemiology and nutrition at the Harvard TH Chan School of Public Health and professor of medicine. at Harvard Medical School. He did not participate in the study. But when researchers looked at the impact of the two diets on blood levels of fats that contribute to heart disease, the Mediterranean diet was the clear winner, according to the study published Friday in The American Journal of Clinical Nutrition. The study looked at low-density lipoprotein, or LDL, known as “bad” cholesterol, and triglycerides, which are a different type of fat in the blood that also contribute to hardening of the arteries. “The keto diet significantly increased LDL cholesterol by 10 percent, while the Mediterranean diet lowered LDL cholesterol by 5 percent,” said Dr. Frank Hu, chair of the department of nutrition at the Harvard TH Chan School of Public Health, who was not involved in the study. study. “The difference between the two diets is quite large, and this may have long-term consequences on cardiovascular disease,” Hu said. While both diets lowered triglycerides, the keto diet did so more significantly, according to the study. However, lowering triglycerides is not as important as raising bad cholesterol, Hu said. “High LDL cholesterol is a much more powerful and important risk factor for cardiovascular disease than triglyceride levels,” he said. “So while both sides were pretty effective in short-term glycemic control, I think the main issue is the potential long-term effects of keto on cardiovascular disease.”
“I tried to give every diet the best chance”
Keto achieves quick weight loss success, proponents say, by putting people into ketosis, a state in which the body begins to burn stored fat for fuel. But to get into ketosis, carbs are drastically reduced to 20 to 50 grams per day. (A cup of cooked rice is about 50 grams.) Eating extra carbs pulls you out of ketosis. The typical American’s daily diet is 50 percent carbohydrates, Hu said, so reducing intake to less than 50 grams is “a huge reduction. It’s hard for people to sustain that.” People often see keto as a “meat” diet and fill their plates with full-fat dairy, sausage, bacon, and other meats with saturated fats, which can contribute to inflammation and chronic disease. However, the study used a “well-designed ketogenic diet,” which limited high protein intake and emphasized non-starchy vegetables, said study author Christopher Gardner, research professor of medicine at the Stanford Prevention Research Center. “I tried to give each diet its best shot. I didn’t try to make it a lousy keto and a good Mediterranean or a lousy Mediterranean and a good keto,” said Gardner, who is also director of clinical and translational research. area at the Stanford Diabetes Research Center. The keto diet prohibits any grains, legumes, and fruit except for a handful of berries. The Mediterranean diet, however, emphasizes filling your plate with fruits, vegetables, beans, lentils, whole grains, nuts and seeds. Both diets agree that “we’re eating too much added sugar and refined grains and not enough vegetables,” Gardner said. “So the whole study was set up to see if there’s an advantage to getting rid of fruits, whole grains and beans on keto — after doing the things that everyone agrees on.” In addition to an increase in bad cholesterol, people on keto had “decreased intakes of thiamin, vitamins B6, C, D and E, and phosphorus,” as well as “incredibly low fiber,” Dr. Shivam said. Joshi, clinical assistant professor of medicine at New York University Grossman School of Medicine. He did not participate in the study. “Whole grains and fruit have positive health benefits, and their exclusion from the keto group raises some concern about long-term health effects,” Willett said. Additionally, he said, “Many people find long-term adherence to a keto diet difficult.” Indeed, the study found that most people quit the keto diet after the survey ended. “They had keto delivered to their home. They had a health educator help them,” Gardner said. “But boom! Most people stopped following the keto diet almost immediately (when that part of the study ended), while many of the Mediterranean dieters were still eating that way when the study ended.” What is the main message of the study? “The No. 1 message for me is that severe restriction of certain healthy carbohydrates is not necessary to improve glycemic control and cardiometabolic health,” Hu said. “You can have a healthy Mediterranean diet or a moderate low-carb diet or a very healthy vegetarian diet. There are different options for people with different dietary preferences.”
