I went to a weight training supplement store. The tub I have was 5 pounds, and cost 85.00 canadian plus tax. Pretty expensive but will go a long way.
Anyway what you need is Vanilla Flavoured Whey Protein Isolate or Vanilla Flavoured Whey Protein Concentrate. Isolate is more expensive then the Concentrate, but not all that much better. If you looking for the tubs, try your local health food stores. Normally Whey Protein is used by muscle builders. The labels break everything down just like food labels except have more information like the amount of specific Amino Acids.
Interestingly enough, my Health food quack er i mean doctor
. Suggested I take this Thiroid supplment to potentially boost my metabolism. Well I noticed that the key ingredient in that supplement was the amino acid L-Tyrosine one of the many amino acids found in my perticular brand of Whey Isolate. Not only is it in my brand, each scoop contains 3 times the amount of one of those supplements. If potassium is lacking, you can also add more to your diet with these, powders.
What I'm getting may seem expensive, but I worked it out and its only like a 1.50 per bowl of Flax meal cereal (including cost of all ingredients). Yes that is more expensive then Corn flakes, but about 1.472842 million times more healthy. Besides a single Egg McMuffin around here costs like 3 bucks or more.
Hope that helps, But I have to admit I'm no expert on Whey Powders.... See NL or Firelady for that.