The Blood Type Diet, developed by Dr. Peter D’Adamo, hypothesizes that your ABO blood type determines how your body digests food and utilizes nutrients. This theory suggests that genetic markers influence your ideal dietary composition. For Type B individuals, the recommendations are based on the idea that this blood type emerged from nomadic, migrating tribes, leading to a robust and adaptable digestive system. The guidelines for Type B Positive individuals are characterized by a varied, omnivorous approach.
Protein Sources for B Positive Individuals
The Type B diet embraces a wide variety of proteins, reflecting the nomadic ancestral history. Beneficial meat choices include lamb, mutton, and venison, which support the Type B metabolism. Fish and seafood are also highly recommended, such as cod, salmon, haddock, and mackerel, providing omega-3 fatty acids and lean protein. Eggs are classified as a neutral or beneficial protein source and can be included regularly.
A unique aspect of the Type B plan is the inclusion of dairy products, as this blood type is theorized to be the most tolerant of milk sugars and proteins. Beneficial dairy options include goat milk, yogurt, kefir, cottage cheese, and mozzarella. Type B individuals are advised to avoid chicken, which is thought to contain a lectin that negatively affects the immune system. Other meats to avoid are pork products, shellfish, and cured meats.
Grains, Starches, and Legumes
The consumption of grains and starches for Type B individuals involves specific exclusions. The main instruction is to eliminate wheat, corn, and rye, which are labeled as “Type B toxic.” Their lectins are believed to interfere with insulin efficiency and metabolic rate. This restriction extends to all wheat products, including whole wheat bread, farina, and wheat germ. Buckwheat is also avoided.
Type B blood is well-suited for many rice products, such as brown rice, basmati rice, and puffed rice, which serve as acceptable starch bases. Oats, including oatmeal and oat bran, are classified as beneficial for their fiber content. Legumes present a mixed profile. Lentils, black beans, and garbanzo beans are avoided due to their specific lectins, but kidney beans, navy beans, and lima beans are considered neutral or beneficial additions.
Produce Recommendations
The produce section of the Type B diet is broad, encouraging the daily consumption of fruits and vegetables to support health and immune function. Green leafy vegetables are highly beneficial, including kale, collard greens, broccoli, and various cabbages. Root vegetables such as beets, carrots, and sweet potatoes are also well-tolerated and provide complex carbohydrates.
A few items are specifically targeted for avoidance because of incompatible lectins. These restrictions include tomatoes, which contain a lectin thought to be inflammatory for Type B individuals. Recommended fruits include pineapple, plums, bananas, and cranberries, which are considered helpful for Type B digestion and overall health.
Evaluating the Blood Type Diet Theory
The Blood Type Diet is a highly popularized concept, but it lacks robust, peer-reviewed scientific validation. A systematic review published in 2013 found no direct evidence to support the claim that following a diet based on ABO blood type provides health benefits. The theory remains largely anecdotal, and the proposed link between blood type and dietary lectin interaction has not been clinically proven. Observed improvements in health or weight loss are often attributed to the general consumption of whole, less-processed foods, which is common in all versions of the diet. Individuals considering this or any major dietary change should always consult a registered dietitian or physician.