1) Whey
Whey contains all the essential amino acids and is particularly high in the branched-chain amino acids and glutamine. Whey is considered a fast acting protein - i.e. if you consume a 30 gram serving of whey on an empty stomach, levels of blood amino acids peak about one hour afterwards and return to pre-meal levels by 3 - 4 hours.

2) Fish
Eating fish improves your insulin sensitivity which means you need less insulin to transport glucose and amino acids into your cells. Less insulin may mean less fat deposition.

3) Soy
Soy protein is comparable in digestibility to other high-protein sources such as meat, milk, fish and egg. Research has shown soy-based meal replacement powders to be effective at lowering body weight, fat mass and reducing LDL cholesterol.

4) Milk
Milk contains all of the essential amino acids and has been shown to provide therapeutic value for either treatment or prevention of disease. If you are trying to lose weight, always stick with skim milk.

5) Chicken
Chicken also contains all of the essential amino acids and can help decrease total cholesterol. Remove the skin from the chicken if you are trying to lose weight.

6) Casein
Casein is the main protein in milk and can appear in various meal replacement powders. Casein clots in the stomach making its absorption a bit slower then whey which is why it is called a slow-acting protein.

7) Eggs
Egg is not only affordable but it is also a great source of protein and the yolk is full of vitamin and minerals. People who reported eating four or more eggs a day had lower cholesterol levels then those who ate one egg or less.

8) Beef
Beef contains all of the essential amino acids and is an excellent protein source loaded with zinc and iron. The key to eating beef and losing weight is to ensure the beef is always lean so remove all visable fat before cooking.