Why is shrimp banned but crab permitted, when both are crustaceans?
Shrimp vs crab
What the system says
This is one of the system's most contested details: shrimp and squid are banned while crab and fish are allowed. The founder offered no clear scientific justification for the distinction, and it's typically asserted without explanation. Some followers attribute it to claims about each animal's diet underwater.
What science says
Scientifically: there's no meaningful health difference between shrimp and crab. Both are lean protein rich in omega-3, and both can trigger allergies in the same crowd. The distinction in the system appears arbitrary rather than scientific.
If you follow the system strictly, stick with crab and fish. If you don't have an allergy, well-cooked shrimp is an excellent healthy choice.