What milk should I use?
Use the milk that fits your calories, protein needs, digestion, and taste. Cow's milk provides protein, carbohydrate, and micronutrients. Skim and low-fat versions reduce calories. Whole milk adds calories and fat, which may help during weight gain and hinder during fat loss.
Plant milks vary widely. Soy milk is usually the closest common plant option for protein. Almond, oat, rice, and coconut milks may be useful for taste or lactose avoidance, but many are low-protein and can include added sugar or fat. Read the label instead of assuming all "milk" products behave the same.