Wondering if using whey protein will lead to weight gain? Holly Roper, our in-house registered nutritionist, says: “Whey protein powder itself, used in moderation, does not directly cause weight gain. However, consuming excessive amounts of any protein powder (or any food source for that matter), without balancing it with a proper diet and exercise routine, can potentially lead to weight gain. Always stick to the recommended serving size listed on the product and use alongside a healthy, balanced diet.”