Al Roker recently revealed that he lost “about 45 pounds in the last several months” by combining a daily walking routine with a low-carb diet. The 67-year-old weather anchor revealed on the TODAY show Monday he eats about 100 grams of carbohydrates daily.

Roker is living proof that the key to losing weight isn’t counting calories but cutting back on carbohydrates. A new study published in the American Journal of Clinical Nutrition backs up Roker’s plan. Lead author Dr. David Ludwig says that the “body fights back against calorie restriction.” The endocrinologist and professor of pediatrics and nutrition at Harvard Medical School says that limiting calories slows down metabolism and causes people to be hungrier.

According to Fox News, Ludwig says that it’s not so much that eating too many calories leads to weight gain, but the high sugar content of certain carbohydrates that triggers the pancreas to release the hormone insulin and store too much energy. When our bodies make too much insulin, the fat cells get programmed to hoard calories, he says.  The low-carb diet the participants ate in Ludwig’s study consisted of 20% carbs, 60% fat, 20% protein.

Low-carb diets are also recommended for those suffering from diabetes as it helps control blood glucose levels. Out of the three energy-providing macronutrients ─ carbohydrate, protein, and fat ─ carbohydrates have the greatest effect in raising blood glucose levels. Protein has a small to moderate effect and fat has the smallest effect, says Diabetes.co.uk.

Ludwig suggests our approach to weight loss has been backward.

“Given the choice between bread and butter, for years we focused on getting rid of the butter,” he said. “But maybe between the two, the bread is the bigger issue.”

Dr. Jeff Vollek, at Ohio State University, has researched low carbohydrate diets for 25 years and says that research proves people who follow a low-carb diet can lose up to 10% of their body weight and keep it off.

“When you limit carbohydrates, the body gets really good at burning its own body fat because it doesn’t have a lot of sugar to burn for fuel,” said, according to Fox News. “The vast majority of adults in the U.S. (well over 100 million people) are consuming too many carbs relative to their tolerance, which is why low-fat diets don’t work for most people. A strong body of research demonstrates that cutting back on carbs is a safe, effective, and sustainable approach to improving weight and metabolic health.”