Carbs stimulate excessive appetites; researchers say it could explain why low-carb diets work

• In a study appearing in Tuesday's "Annals of Internal Medicine," Temple researchers found that people on low-carb regimens such as the Atkins diet spontaneously reduced their calories by 30 percent despite being offered unlimited helpings of protein-rich, high-fat foods, such as red meat.
• On average, they cut out 1,000 calories a day when restricted to bird-like portions of carbs.
• The study, funded by the American Diabetes Association and the National Institutes of Health, is the only trial of the Atkins diet ever done in a hospital setting where every calorie could be measured, Temple researchers said.
• Appearing first in the 1860s, low-carb diets became hugely popular in recent years, spurring millions of people to try them.
• Studies have shown they can work, at least short term, but the reason has been hotly debated.
• "This study is very useful because it tells us it is about calories at the end of the day," said Gary Foster, a University of Pennsylvania obesity expert.
• Stuart Trager, medical director for Atkins Nutritionals, said the research confirmed a low-carb diet fosters weight loss because it helps people consume fewer calories.
• But other studies have suggested that metabolism plays a role, Trager said.
• Unlike other research, where patients tracked their eating and exercise patterns, the Temple study measured every calorie that a group of 10 obese patients consumed and spent.
• The patients, who also had Type 2 diabetes, ate their normal fare the first week, averaging 3,111 calories a day.
• Their calories dropped to an average of 2,164 a day and they lost on average 4 pounds each over two weeks.
• Hawk said he carried 315 pounds on his 6-feet, 1-inch frame when he entered the trial.