Nutrition shakes are often used as meal replacements to jump-start weight loss, build muscle or supplement your diet, so it is important that the shake you choose contains a sufficient amount of protein, minerals and vitamins for good health. Most nutrition shakes contain only a small amount of fiber, and many have excessive sodium. The protein content and quality is the most distinguishing element for comparing nutrition shakes.
Mayoclinic.com recommends consuming 50 to 175 g of protein or 10 to 35 percent of total daily calories, based on a 2,000-calorie diet. Protein is necessary for the growth, maintenance and repair of every cell, tissue, muscle and organ in your body. Nutrition shakes supply protein from various sources without the calories and fat content of many animal-based proteins such as meat. The most common protein sources in nutritional shakes include whey, soy and casein, each with unique properties.
Nutrition shakes made with whey contain the highest quality of protein. Whey protein, derived from milk without the fat or lactose sugar, is the fastest digested and absorbed protein. Leucine, a potent amino acid in whey, stimulates rapid protein synthesis releasing all the amino acids required for maximum muscle maintenance, according to Jeff Volek, PhD, R.D. of Nutrition Express. A popular brand of 100 percent whey protein nutritional shake provides 23 g of protein with 110 calories per 28.4 g scoop. The saturated fat content is 1 g, total carbohydrate content is 2 g, sugar content is 1 g and sodium content is 60 mg. The whey nutrition shake provides 10 percent daily value, or DV, for calcium, according to MyFitnessPal.
A 2008 study published in the “Nutrition & Dietetics” conducted at the University of Wollongong, Australia, showed that the type of dietary protein significantly affects weight. Whey protein was the most effective in stabilizing body mass, decreasing appetite and stimulating fat metabolism in addition to lowering insulin levels.
Nutrition shakes that derive protein from soybeans, usually in isolate form, contain the complete group of amino acids. Shakes with soy are not as easily assimilated as whey shakes but are comparable to meat and milk in digestibility. A brand of nutrition shake that contains protein from soy provides 25 g of protein and 120 calories with 2 g of fat per scoop. The soy shake provides 6 percent DV for calcium and 25 percent DV for iron. Sodium content is 310 mg. An added benefit of soy protein in nutritional shakes is associated with cholesterol in blood serum. A 2007 study by the National Institute of Health and Nutrition in Tokyo and published in the “American Journal of Clinical Nutrition” found that total cholesterol including LDL, the “bad” cholesterol, was lowered by the consumption of soy protein without significantly lowering HDL cholesterol levels.
Casein Nutrition Shakes
Nutrition shakes made with casein, the most abundant protein in milk, are often harder to digest than shakes based on whey. However, the slower rate of digestion means a steady longer-lasting release of amino acids into the body. A typical nutrition shake made with casein contains 24 g of protein with 120 calories and 1 g saturated fat. The carbohydrate content is 3 g with 1 g of dietary fiber. The casein shake contains no sodium and supplies 60 percent DV for calcium. Many nutrition shakes are made with a combination of casein and whey since whey rapidly increases protein synthesis and casein blocks protein breakdown.