Protein does not make you fat as such. Eating or drinking too much protein "can" make you fat if you are not exercising. Protein does have calories and like all foods which contain calories if you eat too much and don't use up what you are eating, then it can get stored as fat - though protein is not the first thing that gets stored as fat.
Usually the order of foods that can make you fat are:
1. fats
2. carbohydrates
3. proteins.
LA Muscle's LA Whey is very low in fat and has a great sodium to potassium ratio. So out of all protein powders out there, it is the least likely to get you fat if you were to have too much of it. If you are training hard and heavy in the gym, you should not worry about getting fat from protein as it is unlikely.