If you find that consuming enough protein to meet your dietary goals -- whether for mass gain or fat loss -- to be too difficult with whole foods, consuming a protein isolate may be beneficial. Protein isolates are low in fat and carbohydrates and tend to be relatively low in calories. According to research from the May 2004 edition of the "Journal of the American College of Nutrition," a protein-rich, reduced calorie diet can be highly effective for weight loss.
Whey Protein Isolate
Whey protein isolate is a dairy product and tends to be low in lactose or lactose-free, but lactose content varies by brand, so check labels before use. Whey protein isolate is low in calories, with 111 per 30 g serving, and contains 27 g of protein, .5 g of carbohydrates and no fat. Whey protein isolate is widely available and research supports its effectiveness. A September 2010 article from the "Journal of the International Society of Sports Nutrition" indicates that using whey protein isolate after exercise can help you maintain strength for subsequent workouts.
Soy Protein Isolate
Soy protein isolate is made from soybeans, and may be preferable to other vegetable protein sources because it is one of the few plants to provide all of the essential amino acids, making it a complete protein. Each 31 g scoop of soy protein isolate contains 110 calories, with 1.5 g of fat, 2 g of carbohydrates and 25 g of protein. According to research from the September 2009 issue of the "Journal of Applied Physiology," soy does not promote muscle protein synthesis, a key factor in muscle growth, to the same degree as whey.
Wheat Protein Isolate
Wheat protein isolate is a grain-based protein supplement, but it may not be appropriate for everyone. Wheat products contain gluten, a type of protein that those with celiac disease cannot digest properly. Ingesting gluten leads to adverse gastrointestinal effects in these individuals. Wheat protein isolate contains 100 calories per 24 g serving, with 1 g of fat, 3 g of carbohydrates and 20 g of protein.
Beef Protein Isolate
Beef protein isolate can be a suitable protein alternative for those who have gluten and lactose intolerances or simply prefer animal products. Beef can be a desirable source of protein because it naturally contains creatine, an amino acid that may help to increase your strength. Each 30 g serving of beef protein isolate contains 120 calories, with 28 g of protein, no carbohydrates and less than .5 g of fat.
- Journal of the American College of Nutrition: The Effects of High Protein Diets on Thermogenesis, Satiety and Weight Loss: A Critical Review
- LIVESTRONG.COM MyPlate: Calories in Whey Protein Isolate (IsoFlex)
- Journal of the International Society of Sports Nutrition: Whey Protein Isolate Attenuates Strength Decline After Eccentrically-Induced Muscle Damage in Healthy Individuals
- LIVESTRONG.COM MyPlate: Calories in Soy Protein Isolate Powder (Chocolate) (Puritan's Pride)
- Journal of Applied Physiology: Ingestion of Whey Hydrolysate, Casein, or Soy Protein Isolate
- LIVESTRONG.COM MyPlate: Calories in Protein Isolate Wheat Protein Supplement
- LIVESTRONG.COM MyPlate: Calories in Beef Protein Isolate (True Protein)
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This article reflects the views of the writer and does not necessarily reflect the views of Jillian Michaels or JillianMichaels.com.