Levin’s team went further, testing the effects of rotating an obesity-susceptible strain of rats between three different diets. The first diet was ordinary rat pellets, the second diet was the same palatable diet as the previous experiment, and the third diet was a highly palatable milkshake-like meal-replacement beverage called Ensure105 (specifically, the chocolate flavor). As expected, the rats began overeating and gaining weight and fat on the palatable diets. In fact, the rats eating Ensure almost doubled in weight over ten weeks—an impressive feat.
