How to Compare Diet Shakes

Diet shakes are convenient beverages that offer protein, carbohydrates and fat. WebMD calls diet shakes "the most proven weight loss supplements," as studies suggest they aid in weight loss. Many take the place of a meal, or can be used as a snack. When comparing diet shakes, consumers must account for their own dietary needs and taste preferences.

Protein Content

Diet shakes come in various flavors, from strawberries and cream to mocha or just plain chocolate.

For fat loss, choose diet shakes with 50 percent or more of the calories coming from protein, according to Jose Antonio, chief executive officer and co-founder of the International Society of Sports Nutrition. Slim-Fast, marketed for weight loss, provides the majority of calories from protein, with the rest from carbohydrates and a small amount of fat.

Body builders and athletes should choose protein shakes, with up to 60 percent of the calories coming from protein. Normal adults looking to maintain their weight should seek shakes with more fat than the weight-loss shakes, and more carbohydrates than the protein shakes--meaning less protein.

Protein Source

The protein in diet shakes comes from a variety of sources. Whey, soy, eggs, casein and milk are all popular ingredients. The different sources are absorbed by the body differently and are metabolized differently. Whey protein is quickly absorbed but burns off more quickly than casein protein. Soy protein is a vegan choice, and contains estrogen which may help regulate women's hormone levels while delivering amino acids.

Convenience

Try mixing a diet shake in your blender and compare the taste to a canned version.

Diet shakes are offered in cans or as powders. While cans are easy to use--just open and drink, some consumers complain of a metallic aftertaste. Diet shakes made in a blender or shaker get higher marks for taste, but require time and equipment to make.

Consult Your Doctor

Before starting any diet program or drastically changing your diet, consult with your physician. A doctor or dietitian can help you determine your calorie, protein, and carbohydrate needs so you can pick the right diet shake for your body.