A new study suggests the paleo diet could have the opposite of its intended effect: it caused weight gain and increased glucose intolerance in lab mice. The paleo diet is based on foods presumed to have been eaten by early humans, consisting primarily of meat, fish, vegetables, and fruit. The diet excludes dairy or grain products and processed foods.

The study was conducted in Australia, and the results were published in the journal Nutrition & Diabetes. Mice that were fed foods similar to the paleo diet gained 15 percent of their body weight within two months. They also showed increased glucose intolerance, which can lead to type 2 diabetes. 

Sources: U.S. News & World Report | Nutrition & Diabetes