Have low-fat diets made us fatter?

Since the 1960s, when experts started advising people to eat less fat—based on the belief that a high-fat diet led to a high-fat body—obesity has skyrocketed. Recent evidence suggests that all those years of focusing on ways to get fat out of foods has actually contributed to the obesity epidemic.

“Despite eating less fat, we are fatter than ever before,” said David Ludwig, professor of nutrition at Harvard T.H. Chan School of Public Health, in the January 2016 issue of Boston magazine.

Over the past 20 years, Ludwig has conducted research aimed at teasing out what low-fat diets do to our bodies. He’s found that low-fat foods brought to market over the past 40 years—high in refined carbohydrates aimed at making the foods more palatable—actually raise our insulin levels, trigger our fat cells to hoard calories, slow our metabolism, and make us hungrier.

Ludwig’s advice—outlined in his new book titled Always Hungry? Conquer Cravings, Retrain Your Fat Cells & Lose Weight Permanently—is to stop focusing on low-fat foods and calorie counting. Instead, he says, we should opt for natural, unprocessed foods that take time to digest and that deliver energy to the bloodstream in a moderate way instead of in a big rush, the way processed carbohydrates do. And he says that a healthy diet should include healthy fats to boost satiety.

Said Ludwig, “The calorie-balance approach to weight control, enshrined in the low-fat diet, has proven utterly ineffective.”

Read the Boston Magazine article: If David Ludwig Is Right, Everything We Thought We Knew About Obesity—and Low-Fat Diets—Is Wrong

Read a Forbes Q&A with David Ludwig: Will The ‘Always Hungry’ Diet Revolutionize Weight Loss? A Q&A With The Author, Dr. David Ludwig

Learn more

Low-fat diet not most effective in long-term weight loss (Harvard Chan School release)

Fats and Cholesterol (The Nutrition Source)