Ketogenic diets are diets that are high in fat and protein and very low in carbohydrates. This diet is meant to predominantly burn fats as an energy source. Research has shown that when the human body is experiencing energy restriction—a common occurrence with diets—human bodies tend to lower the amount of energy being used up by decreasing the resting metabolic rate (RMR).

Scientists use the term metabolic adaptation to describe this RMR decrease and a related decrease in energy being used. Resting metabolic rate is essentially the amount of energy needed for the human body to perform basic activities while it is resting, such as breathing and brain functions.

Below are some studies that investigated the health effects of a ketogenic diet. 

Long term effects on weight loss

Some ground-breaking research on ketogenic diets showed that extremely low-calorie ketogenic diets were capable of causing weight loss and assisting people in maintaining that weight loss for a period of up to two years. Researchers conducted this study because they wanted to test the hypothesis that very low-calorie ketogenic diets trigger a neutral reaction in terms of resting metabolic rate. They theorized that this would diminish the likelihood of body weight regain. Their intriguing results were published in the Nutrition & Metabolism journal.¹

The low-calorie ketogenic diets the researchers had the obese patients follow did result in maintained weight loss, however, the diet did not lead to the expected RMR decrease. They suspect this neutral RMR reaction might have occurred because lean muscle mass is often preserved when following this diet.

The findings presented by these researchers demonstrated that a low-calorie diet was effective in maintaining normal resting metabolic levels, preserving lean muscle mass, and ultimately preventing metabolic adaptation—and perhaps weight regain for obese patients.

Ketogenic diet may not necessarily work long-term

To determine the better long-term weight loss rates, researchers from Iuliu Hatieganu University of Medicine and Pharmacy in Romania conducted a study of the ketogenic diet compared to a low glycemic index / nutrigenetic diet.² Their results were published in the journal BMC Nutrition.

Patients in the ketogenic diet group ate no more than 35 grams of carbohydrates, no more than 10% total calories from fat, and protein intake between 1.2 g/kg bodyweight for women, and 1.5 g/kg bodyweight for men. 

Patients in the low-GI nutrigenetic diet group were DNA tested, and a diet plan was specifically developed based on the DNA testing. However, limits were placed on carbohydrates and saturated fat intake.

Both groups participated in 30-45 minutes of exercise per day, five days …….

Source: https://medicalnewsbulletin.com/unexpected-health-effects-of-a-ketogenic-diet/