Protein powders blended with milk, water, juice or other liquids provide a quick, convenient way to boost your protein intake after a workout or in place of a meal. Made from whey, soy, eggs, casein or hydrolyzed collagen, the nutritional content of protein powders vary widely, says Linda Aills, R.D., lead researcher in a study published in the September 2008 issue of "Surgery for Obesity and Related Disease. Shop carefully to select the right protein powder for your needs.
Weight loss surgery patients should avoid protein powders that do not provide all nine essential amino acids needed by the body, cautions Aills. An incomplete protein -- made from hydrolyzed collagen or amino acid dose that's low in one or more essential amino acids -- will not help to prevent loss of lean muscle mass while you lose weight. Instead, choose a protein powder made from a complete protein source such as egg white, whey, soy, brown rice or casein.
If you suffer from lactose intolerance, avoid whey concentrate protein powders, says Aills. Digesting milk sugars requires a sufficient amount of lactase, an enzyme produced in the small intestine, according to the National Digestive Diseases Information Network. Lactose intolerant individuals experience mild to moderate symptoms such as bloating, abdominal cramping, vomiting and diarrhea within 30 minutes to two hours of consuming products containing lactose. Instead, choose lactose-free protein powders made from whey isolate, soy or egg whites, says Aills.
Most Americans get more than enough protein through dietary sources, says the Centers for Disease Control and Prevention. Healthy adults generally need between 46 to 56 grams of protein per day, a goal you can meet by eating just one serving each of meat, milk and yogurt and 1 cup of cooked dried beans per day. Unless you need additional protein because of disease, advanced age, weight loss surgery or athletic training, adding protein powder to your usual diet may add too many calories to your daily intake. If you must limit sugar in your diet, look for products with approximately 5 grams of sugar per serving.
In addition to adding calories, excess protein may harm your liver or kidneys by forcing them to work harder to excrete waste products. If you also restrict carbohydrates while increasing protein, you risk developing constipation, diverticulitis and certain types of cancer due to the resulting fiber and nutritional deficiencies. If you do not need additional protein because of endurance training, disease or weight loss surgery, consult your health care provider or nutritionist before adding supplements.
Independent laboratory tests of three servings each of 15 protein supplement products revealed varying amounts of heavy metals in each of the drinks and powders, according to a report published in the July 2010 issue of "Consumer Reports." The highest levels of heavy metals -- arsenic, lead, cadmium and mercury -- appeared in the chocolate and vanilla creme flavors of Muscle Milk powder.