What should O+ avoid eating?

What People with O+ Blood Type Should Avoid Eating

If you have O+ blood, you're in the majority—this is the most common blood type worldwide. But according to some health theories, your blood type might influence how your body responds to certain foods. One such theory, popularized by Dr. Peter D’Adamo in his book Eat Right for Your Blood Type, suggests that people with Type O, especially O+, thrive on a high-protein, low-carbohydrate diet.

So, what should O+ individuals avoid? The theory recommends steering clear of grains, legumes, and dairy products. These foods, it’s argued, may interfere with digestion and metabolism in people with Type O blood due to differences in stomach acidity and immune response. Instead, the focus should be on lean meats, poultry, fish, and a variety of vegetables.

While this approach isn’t universally accepted by the medical community—many scientists point out that large-scale studies don’t strongly back the blood-type diet—it’s still popular among those looking to optimize their health through personalized nutrition. Some O+ eaters report increased energy, better digestion, and improved weight management when following these guidelines.

That said, eliminating entire food groups should be done with caution. Grains and legumes are rich in fiber and essential nutrients, and dairy is a key source of calcium and vitamin D. Before making drastic changes, it’s wise to consult a healthcare provider or nutritionist.

In the end, while the blood-type diet may not be scientifically proven for everyone, listening to your body and eating whole, unprocessed foods remains one of the healthiest choices—regardless of blood type.