Researchers have found an ingredient in milk that prevents obesity in mice, even with diets high in fat. The ingredient is nicotinamide riboside, which is known to increase the activity of the gene SIRT1. This gene has a direct impact on metabolism and longevity; in this study, researchers targeted that gene directly.
Mice that took nicotinamide riboside in high doses were protected against obesity and actually became better runners due to greater endurance in their muscles. The bad news is that drinking milk on its own to achieve these benefits would be very difficult; the good news is that this could be a possible supplement in the future.
Tests on humans are needed to confirm these findings, but the ingredient is still present in milk, even if not in large amounts, so pour another glass and drink up for multiple health benefits.