If your protein powder supplies the wrong kind of fats, then, you can gain the wrong type of weight. (blog.nkdnutrition.com)
In fact, not getting enough fat, or getting the wrong kind of fat (like vegetable oils promoted by the USDA) has been shown to have a negative impact on IQ later in life. (wellnessmama.com)
While the wrong kinds of fats (see above) can interfere with hormone production, eating enough of the proper fats can really help! (wellnessmama.com)