Nutrition Diet: What Should a B Blood Type Eat?

October 16, 2025 •

3 min read

The blood type diet, developed by naturopathic physician Dr. Peter D'Adamo, is a dietary plan that suggests individuals eat specific foods based on their ABO blood type to improve health. For those wondering what should a B blood type eat, the theory points toward a balanced, omnivorous diet reflecting a nomadic ancestry.

Quick Summary

The Blood Type B diet, based on Peter D'Adamo's theories, suggests an omnivorous eating pattern, including certain meats, dairy, fruits, vegetables, and grains. Key foods to avoid include chicken, corn, and wheat. Scientific evidence supporting this diet is limited, with benefits often attributed to overall healthier eating habits.

Key Points

Omnivorous Diet: The Blood Type B diet is characterized as an omnivorous plan, including a mix of meats, dairy, fruits, vegetables, and grains.
Foods to Avoid: Followers are advised to avoid specific foods, notably chicken, corn, wheat, and lentils, due to alleged interactions with blood type-specific lectins.
Dairy Tolerance: Unlike other blood types in the diet theory, Type B individuals are said to tolerate and benefit from a wide range of dairy products.
Lack of Scientific Evidence: Despite its popularity, the blood type diet lacks scientific support, with studies finding no evidence that eating according to blood type improves health outcomes.
Healthy Choices as Key: Any health benefits from the diet are likely a result of eating more whole, nutrient-dense foods and limiting processed items, rather than following blood type-specific rules.
Consult a Professional: It is crucial to consult a healthcare provider or registered dietitian before adopting a restrictive diet, especially one with limited scientific backing.

The Nomadic Diet: Core Principles for Blood Type B

According to the popular blood type diet theory, individuals with Blood Type B inherited a resilient, nomadic ancestry, allowing for a versatile digestive system capable of handling a broad range of foods. This versatility reportedly allows Type B individuals to thrive on a diet that balances meat, dairy, vegetables, and certain grains, unlike the more restrictive diets suggested for other blood types. Proponents of the diet claim that avoiding specific foods, particularly those containing incompatible proteins called lectins, is key to preventing health issues such as chronic fatigue, autoimmune diseases, and slow-growing viruses.

Recommended Foods for Type B Individuals

For those following the Blood Type B diet, the focus is on a balanced, omnivorous plate that includes dairy, which is generally well-tolerated by this blood type. Recommended foods include lamb, mutton, venison, rabbit, deep ocean fish like cod, salmon, and halibut, as well as dairy products such as yogurt, kefir, milk, goat cheese, and feta. Eggs are considered a good protein source, and grains like oatmeal, brown and wild rice, and spelt are included. Recommended vegetables and fruits encompass leafy greens, broccoli, cauliflower, beets, carrots, bananas, grapes, pineapple, and plums.

Foods to Avoid According to the Blood Type Diet

Certain foods are singled out as particularly problematic for Type B individuals due to specific lectins that are believed to interfere with metabolism and immune function. Foods commonly advised against include chicken due to a lectin said to cause agglutination in Type B blood, grains and legumes like wheat, corn, buckwheat, lentils, and peanuts, which are thought to negatively impact metabolism and nutrient absorption. Sesame and sunflower seeds are also restricted, and some recommendations discourage tomatoes, avocados, and shellfish such as crab, lobster, and shrimp.

Blood Type Diet vs. Evidence-Based Nutrition

Despite its popularity, the blood type diet lacks strong scientific validation and has faced significant criticism from the medical and nutritional communities. A comprehensive review published in the American Journal of Clinical Nutrition found no scientific evidence supporting the health benefits of the diet, regardless of blood type. Critics note that any health improvements observed are more likely due to general dietary changes, such as eliminating processed foods and increasing fruit and vegetable intake, rather than the blood-type specific recommendations.

Comparison: Blood Type B Diet vs. Standard Healthy Guidelines


Dietary Aspect	Blood Type B Diet Approach	Standard Healthy Guidelines (e.g., Mediterranean)
Protein Sources	Emphasizes lamb, mutton, venison, and some fish; avoids chicken and pork.	Recommends a variety of lean proteins, including poultry, fish, eggs, and plant-based sources.
Dairy	Encourages consumption of yogurt, kefir, milk, and most cheeses.	Recommends low-fat dairy in moderation.
Grains	Focuses on rice, oats, and spelt; avoids wheat and corn.	Promotes a wide variety of whole grains, including wheat-based products.
Vegetables	Recommends leafy greens, broccoli, and beets; avoids corn and tomatoes.	Encourages a broad intake of all vegetables.
Rationale	Based on ancestral theories and presumed lectin interactions, lacking clinical proof.	Based on extensive epidemiological and clinical research, emphasizing balanced nutrients.

Conclusion: Making Informed Nutritional Choices

The blood type diet offers a structured framework for eating that may lead to healthier habits, but it is not supported by scientific evidence. While followers might report positive outcomes, these benefits are likely derived from the overall consumption of more whole foods and reduced intake of processed items, a principle common to many effective diets. For Type B individuals, this means that while their prescribed diet may offer some sound nutritional advice, there is no biological reason to strictly follow the blood type-specific restrictions. The most effective approach for long-term health is a balanced diet rich in a variety of fruits, vegetables, lean proteins, and whole grains, personalized to individual needs and preferences. Before starting any restrictive diet, especially one lacking scientific backing, it is always best to consult a healthcare professional or a registered dietitian.

Frequently Asked Questions

The diet is based on the idea that people with Blood Type B have adapted from nomadic ancestors and thus thrive on a varied, omnivorous diet including meat, dairy, fruits, and vegetables.

Proponents claim that chicken contains a lectin that can be incompatible with Type B blood, potentially leading to health issues and weight gain.

No, the blood type diet is not supported by scientific evidence. A 2013 review of existing studies found no clinical evidence to substantiate the health claims associated with the diet.

Recommended dairy products for Type B include yogurt, kefir, milk, and cheeses like feta and goat cheese, as this blood type is believed to tolerate dairy well.

Followers may report improved digestion, increased energy, and better weight management, but these benefits are likely from adopting a healthier, whole-foods-based diet rather than from the blood type-specific rules.

No, the blood type diet advises against consuming wheat and corn, claiming they can cause digestive issues and weight gain for Type B individuals.

Acceptable grains for Type B followers include oats, rice (brown and wild), and spelt.

According to the diet theory, a Type B individual should maintain a balance of both plant-based and animal-based foods, fitting an omnivorous profile.