Type O Blood

Around 40,000 BC, our first human ancestors began hunting and gathering, existing mainly on meat. On a mostly carnivorous diet, they evolved to have high stomach-acid content, which enabled them to efficiently digest meat protein. Type O women today still harbor the DNA that enables them to thrive on meat.

Best Dietary Staples: Eating a low-carb, meat-rich diet will help stablize weight for women with type O blood; while avoiding wheat will prevent allergylike reaction that slows thyroid function in type O women.

Type A Blood

The Neolithic Period between 25,000 and 15,000 BC saw an increase in population and game grew scarce. People began forming large communities and cultivating crops. As their blood type evolved to adapt to this dietary change, their bodies produced fewer meat-digesting acids and enzymes and more grain- and plant-digesting enzymes. Type A antigens also allowed for a stronger immune system to protect the people who lived in groups.

Best Dietary Staples: To this day, type A women thrive on grains, beans, vegetables, fruit and soy, with limited amounts of fish and fowl. And avoiding red meat helps prevent allergylike food reactions with type A antigens.