Among scientists who revel in their unfounded criticism of grain-based foods, few have offered pronouncements more outlandish than David Ludwig, a professor of pediatrics at Harvard Medical School. A publicity hound, Dr. Ludwig once said a parent preparing a bagel and low fat cream cheese would do just as well by simply giving their child a bowl of sugar. In a New York Times opinion piece in 2014, his language was similarly colorful. Carbohydrates, he said, “put fat cells into storage overdrive” for many people. “Like an infection that raises the body temperature set point, high consumption of refined carbohydrates — chips, crackers, cakes, soft drinks, sugary breakfast cereals and even white rice and bread — has increased body weights throughout the population,” he said.

Confident in his conclusion, Dr. Ludwig did concede that his hypothesis had not been specifically tested. Last week, results of exactly such a test were published. The researchers, at the National Institutes of Health, found in a well-controlled study cutting fat intake was more effective at reducing fat than cutting carbs.

In their conclusions, the researchers specifically took aim at Dr. Ludwig’s claims of “a metabolic advantage of carbohydrate restriction for enhancing body fat loss.” The researchers state simply, “Our data support the opposite conclusion.” For grain-based foods, the powerful findings and the plain language to describe them could not possibly be more welcome.