Protein Shakes Linked to Depression and Weight Gain

Protein Shakes Linked to Depression and Weight Gain 2 in 5 Americans report drinking protein shakes regularly. They are most commonly used to supplement diet or bulk up. But new research from the University of Sydney suggests that they may be harmful to overall health. The amino acids that encourage muscle gain could also encourage weight gain. The amino acids compete with tryptophan, a key player in the production of serotonin. This can lead to increased rates of depression. Dr. Samantha Solon-Biet, via 'Daily Mail'