I tend to agree with the blood type diet.

Some ppl (O's) need to have meat/fish in their diet, others (A's) are best as vegetarians. Dairy products or wheat/gluten or peanuts are well tolerated by some and some should completely avoid them.

As an ex personal trainer I was constantly asked for nutrition advice and always (& rightfully so) declined to offer any.

It was clear to me that people's bodies had differences and them disclosing their diets to me over the years made it quite clear that different things work for different people.

The description for my type is quite accurate, as are the dietary recommendations...from my own experience playing with my eating habits for decades (including adhering to a strict vegetarian diet a few times, for years in a couple instances), I know my body works best when avoiding gluten and most grains, all dairy, and eating meat.

Although my diet plan is memorized, I like the app as a convenient reference and it allows you to add other ppl's types to see what you have in common when shopping or making meals.
[link to www.4yourtype.com]