People who start on a new drug also make lots of other lifestyle adjustments. Especially when it's a weightloss drug. You'd get some of that effect, even if t

People who start on a new drug also make lots of other lifestyle adjustments. Especially when it's a weightloss drug. You'd get some of that effect, even if the drug was actually a placebo. But if it's working, then people have an even better motivation to make changes. Yogurt is widely seen as healthy, so people who want to change to a healthier lifestyle might pick it. (Yogurt might actually be healthy, I don't know. That's almost besides the point for the effect here.)