There is strong evidence that ketogenic diets are very effective for weight loss. They can help you lose fat, preserve muscle mass and improve many markers of disease. In fact, many studies have compared the recommended low-fat diet to a ketogenic diet for weight loss. Findings often show the ketogenic diet to be superior, even when total calorie intake is matched. In one study, people on a ketogenic diet lost 2.2 times more weight than those on a low-calorie, low-fat diet. Triglyceride and HDL cholesterol levels also improved.