Does whey protein powder make you gain weight or get chubby?

Excessive calories: Excessive calories from any source (to include whey protein) can lead to weight gain.

The idea behind: protein supplements is that, when combined with weight training, aerobic training and calorie restriction, they help reduce body fat and develop quality muscle mass. So you are trying to gain weight/muscle when you use it properly. By chubby, I assume you mean a gain in fat. Used properly, this should not occur. Meals focused on protein should achieve the same affect. Hope this helps:)