That lack of fiber in supplements is one factor that can cause digestive problems, including constipation and diverticulitis. For that reason alone, Mayo Clinic nutritionist, Katherine Zeratsky, R.D., L.D., recommends following high-protein diets only on a short-term basis. You may be able to avoid some digestive issues by following a high-fiber diet, choosing a protein product that is fortified with fiber or taking a daily fiber supplement, so check nutritional labels when you’re shopping.
If protein supplements consistently put you past your recommended daily requirements, you may be subject to developing kidney problems because the kidneys are involved in breaking down protein. If you already have kidney disease, the Centers for Disease Control and Prevention reports that supplements could further impair the organs, essentially throwing them into overdrive by making them work harder to expel excess waste by-products.
Protein supplements aren’t all bad news, however. In a study published in the journal “Diabetes/Metabolism Research & Reviews” in 2010, obese participants who ate a low-calorie diet that included protein meal replacements lost more weight and fat mass over the course of a year than subjects who did not have the supplements. If you want to add protein supplements to your diet, get approval from your physician or a registered dietitian and use products that have natural ingredients and plenty of vitamins and minerals.