At one point or another—or, more likely, for as long as you can remember—you have avoided foods high in fats because you are heeding the advice of most dieticians and nutritionists, and the medical community at large. But you might be surprised to learn that fat is actually good for you, and the low-fat diet craze is based on faulty science.

The low-fat diet quickly became a high-carbohydrate diet as processed food manufacturers scrambled to replace fat with palatable substitutes. Sugar and starches substituted fats, and suddenly everyone was eating what they thought was a low-fat diet but was really a high-carbohydrate diet in disguise. Along with these changes in diet came unprecedented increases in heart disease, obesity, and type 2 diabetes, all conditions worsened by a diet high in sugar and carbohydrates.

A recent study published in the Annals of Internal Medicine compared the effects of a low-carbohydrate versus a low-fat diet on weight and cardiovascular risk factors in 148 men and women without heart disease or diabetes.

Participants lost more weight and fat mass on the low-carbohydrate diet as well as experienced a decrease in triglycerides and an increase in HDL cholesterol (the “good” cholesterol) than those on the low-fat diet.The researchers concluded, “The low-carbohydrate diet was more effective for weight loss and cardiovascular risk factor reduction than the low-fat diet. Restricting carbohydrate may be an option for persons seeking to lose weight and reduce cardiovascular risk factors.” This is not the first study to find such an effect, but it adds to the evidence stacking up against a low-fat diet.

Participants lost more weight and fat mass on the low-carbohydrate diet as well as experienced a decrease in triglycerides and an increase in HDL cholesterol (the “good” cholesterol) than those on the low-fat diet. This is not the first study to find such an effect, but it adds to the evidence stacking up against a low-fat diet.

Harvard scientists write about the low-fat diet as studied in the Women’s Health Initiative trials, “A growing body of evidence has been pointing to its inadequacy for weight loss of prevention of heart disease and several cancers. The final nail in the coffin comes from an eight-year trial that included almost 49,000 women.”

Interestingly, another study published around the same time analyzed 50 trials comparing low-fat and low-carbohydrate diets on weight loss and concluded that the weight loss was similar for both diets. This analysis did not examine cardiovascular risk factors, however, which tell a more accurate story about what a diet high in carbohydrates—that is, sugars and starchy foods—does to cardiovascular health.

My Skinny Gut Diet is a relatively low-carbohydrate diet, but I do emphasize one difference—it is a high-fiber diet! It includes plenty of nonstarchy vegetables and low-sugar fruits. You see, although fiber is a carbohydrate (did you realize that?), it is not absorbed by the body. Instead, it passes through the digestive tract, promoting digestive health and helping to feed the trillions of good bacteria that live in the gut. So any carbohydrate grams that are fiber are not counted when you’re on the Skinny Gut Diet. But don’t worry, my simple Teaspoon Tracker calculation makes it a cinch to figure out.