others feel lethargic and unwell why high protein diets cause some people to lose weight and some to put it on why Ayurvedic medicine says milk is very beneficial (it is for blood type B), while most people are intolerant of dairy products The blood type diet is not an ideal metabolic diet, as it only takes one genetic marker into account. For some people, especially O types, it works reasonably well. But others, especially A types, often do extremely poorly on it. A major reason for this maybe that O types are told to eat lots of meat and avoid commercial grains, while A types are told to eat a mostly vegetarian diet, including soy which is dangerous. My opinion is that Bob McFerran's metabolic diets are better. If you do decide to try the blood type diets, remember this is a starting point, and individuals may be intolerant of something that otherwise would be beneficial for their blood type. It can be combined with other plans, eg. Food combining (for people with digestive problems) or the Zone (best suited to O types). One O-type ER4YT follower said "I use ER4YT to determine what to eat, and the Zone to determine when to eat it". These are valuable resources, but it is important to read the book first (and of course, find out your blood type). Remember, with any new eating plan, it may take a few weeks before you start to see results, so don't be discouraged if