Keto proponents claim the diet reduces appetite, melts abdominal fat, and boosts mental sharpness; once a person is over the first few days of “keto flu,” a feeling of malaise, fatigue, and brain fog.Studies have shown at least a short-term improvement in blood sugar in people on keto. Keto Diet versus the Mediterranean. Which Better?
A ketogenic diet is one in which most calories come from fat (70-75%). A moderate amount of calories come from protein (20-25%). Only a small number of the calories come from carbohydrates (5%).
The diet forces the body to burn fats rather than carbohydrates for energy. Typically, the carbohydrates you eat are turned into glucose in the body, which is used for energy around and in the brain. But, if you don’t eat enough carbohydrates, your body has a backup system of burning fat instead. The liver can use stored fat and the fat you eat for energy. Stored fat is broken into two parts, fatty acids and ketone bodies. Ketone bodies power the brain instead of glucose. This state of having a lot of ketone bodies in your blood is called “Ketosis.” The liver can also make or release its glucose through two processes(gluconeogenesis and glycogenolysis), as glucose is still needed for normal body function.
During the pandemic, a new controlled clinical trial compared the two diets by asking 33 people with prediabetes or diabetes to do both diets for three months, one after the other. During the first four weeks of each diet, participants received either healthy keto- or Mediterranean-based meal deliveries, then followed meal plans on their own.
Researchers monitored participants’ weight, blood sugar (glucose) levels, cardiovascular risk factors, and adherence to the diet. Which diet was still standing at the final bell?
“Both diets improved blood glucose control to a similar degree, and both groups lost a similar amount of weight,” said leading nutrition researcher Dr. Walter Willett, a professor of epidemiology and nutrition at Harvard T.H. Chan School of Public Health and professor of medicine at Harvard Medical School. He was not involved in the study.
However, when researchers examined the impact of the two diets on levels of blood 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 tracked low-density lipoprotein, or LDL, known as the “bad” cholesterol, and triglycerides, which are different type of fat in the blood that also contributes to the hardening of the arteries.
“The keto diet significantly increased LDL cholesterol by 10%, while the Mediterranean diet decreased LDL cholesterol by 5%,” said Dr. Frank Hu, chair of the department of nutrition at Harvard T.H. Chan School of Public Health, who was not involved in the 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 reduced triglycerides, the keto diet did so more significantly. However, the reduction in triglycerides is not as significant as the rise in 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 quite effective in short-term glycemic control, I think the main issue is the potential long-term effects of keto on cardiovascular disease.”
The diet is closely tied to areas of olive oil cultivation in the Mediterranean region. The pyramid, structured in light of current nutrition research and representing a healthy Mediterranean diet, is based on the dietary patterns of Crete, Greece, and southern Italy circa 1960 at a time when the rates of chronic disease were among the lowest in the world. Adult life expectancy was among the highest, despite limited medical services. These findings were established in large part by scientist Ancel Keys.
The pyramid is divided into daily, weekly, and monthly frequencies but does not recommend serving sizes.
The Mediterranean diet is based on the traditional foods that people used to eat in countries bordering the Mediterranean Sea, including France, Spain, Greece, and Italy.
Although there are no strict rules or regulations for the diet, it typically encourages fruits, vegetables, whole grains, legumes, nuts, seeds, and heart-healthy fats. Processed foods, added sugar, and refined grains should be restricted.
Numerous studies have shown that the Mediterranean diet can promote weight loss and help prevent heart attacks, strokes, type 2 diabetes, and premature death.
For this reason, the Mediterranean diet is often recommended for those looking to improve their health and protect against chronic disease.
‘Each Diet has a different need.
Proponents say keto accomplishes quick weight-loss success by putting people into ketosis, a state where the body begins to burn stored fat as fuel. But to get to ketosis, carbohydrates are drastically slashed to 20 to 50 grams daily. (A cup of cooked rice is about 50 grams.) Eating additional carbs knocks you out of ketosis.
What is the key message of the study?
“The No. 1 take-home message for me is that severe restriction of some healthy carbohydrates is not necessary to improve glycemic control and cardiometabolic health,” Hu said.
“You can do a healthy Mediterranean, moderate low-carbohydrate, or very healthy vegetarian diet. There are different options for people with different food preferences.”