What Type of Meat is Good for O-Positive? Debunking the Blood Type Diet

October 14, 2025 •

5 min read

The blood type diet, conceptualized by naturopathic doctor Peter D'Adamo, suggests that people with type O blood should consume a high-protein diet rich in lean meats and fish, similar to their alleged hunter-gatherer ancestors. While proponents claim benefits like weight loss and better digestion, scientific evidence does not support the theory that what type of meat is good for O-positive is determined by blood type alone.

Quick Summary

This article examines the meat recommendations for O-positive individuals based on the popular blood type diet theory, detailing the specific lean meats, poultry, and fish considered beneficial. It also addresses the significant lack of scientific evidence for the diet's claims and highlights the importance of general healthy eating principles over blood type-based restrictions.

Key Points

Blood Type Diet Theory: The blood type O diet, developed by Peter D'Adamo, suggests a high-protein intake from lean meats and fish, based on the unsubstantiated theory of hunter-gatherer ancestry.
Recommended Meats: For O-positive individuals, the diet lists beneficial meats as lean red meats (beef, lamb, venison), poultry (chicken, turkey), and fatty fish (salmon, mackerel).
Meats to Avoid: The diet advises avoiding pork, goose, and certain seafood like catfish and caviar.
Lacks Scientific Evidence: The blood type diet is widely rejected by the scientific and medical communities due to a lack of evidence supporting its core claims.
Healthy Habits are Key: Any health benefits from following the diet are likely a result of incorporating healthier whole foods and exercise, rather than blood type-specific food choices.
Balanced Diet is Preferred: A nutritionally balanced diet tailored to individual needs and health goals, rather than blood type, is the recommended approach.

Understanding the Blood Type Diet for O-Positive Individuals

The blood type diet is based on the idea that an individual's blood type dictates their optimal dietary needs. According to its creator, Dr. Peter D'Adamo, people with type O blood, which he theorizes represents the oldest human blood lineage, are best suited for a high-protein, meat-heavy diet, reflecting the ancestral hunter-gatherer lifestyle. The diet suggests that Type O individuals possess a robust digestive system with higher levels of stomach acid, enabling them to process animal protein and fat more efficiently than other blood types.

The diet's framework proposes that certain proteins called lectins, found in specific foods, can agglutinate (clump together) cells in the body, causing health problems. D'Adamo claims that these lectins interact differently depending on a person's blood type. For Type O individuals, this supposedly means avoiding foods like certain grains, legumes, and dairy, while focusing heavily on animal proteins.

Beneficial Meat Choices for the O-Positive Diet

Based on D'Adamo's theory, the diet identifies specific meats and seafood that are highly beneficial for those with an O-positive blood type. These recommendations emphasize lean, unprocessed sources of protein and often include wild-caught fish due to their omega-3 content.

Lean Red Meats

Beef: Lean ground beef, beef organ meats.
Lamb: A recommended lean red meat option.
Venison: Game meat is considered an excellent protein source.
Mutton: Another lean red meat suggested for Type O individuals.
Veal: Included in the list of beneficial red meats.

Poultry

Chicken: A recommended protein source.
Turkey: Another lean poultry option.
Goose is specifically noted as a poultry meat to avoid.

Fish and Seafood

Cod: A beneficial fish choice.
Herring: A good source of omega-3s, but not pickled herring.
Mackerel: Rich in omega-3 fatty acids.
Salmon: Another excellent source of omega-3s.
Sardines: Recommended for their omega-3 content.
Halibut: Included in the list of beneficial fish.

Meat and Seafood to Avoid

The blood type diet also specifies certain types of meat that Type O individuals should avoid, theorizing that they contain lectins that are harmful to their system or that they are simply less digestible. These include:

Pork: Avoid all forms of pork.
Goose: Specifically excluded from recommended poultry.
Catfish: A fish to be avoided.
Caviar: Another seafood option to limit.
Pickled Herring: While plain herring is fine, pickled varieties should be avoided.
Octopus: Specifically listed as something to avoid.

The Scientific Verdict: Evidence vs. Theory

Despite the diet's popularity, the scientific consensus is that the blood type diet lacks robust evidence. A comprehensive review published in the American Journal of Clinical Nutrition found no scientific evidence to support the benefits of blood type diets. Critics, including many nutrition experts, point out that the theory relies on unsubstantiated claims and broad generalizations. The idea that specific lectins in foods interact with blood types in a harmful way has not been scientifically validated. Furthermore, the evolutionary basis of the diet has been questioned, with some evidence suggesting Type A was the first blood group to evolve, not Type O.

Any reported health improvements from following a blood type diet are more likely due to the general shift toward eating whole, unprocessed foods and avoiding junk food. Since D'Adamo's diet plans, including the one for Type O, emphasize exercise and the consumption of nutrient-dense whole foods like lean protein, fruits, and vegetables, these principles align with standard healthy eating recommendations. The Harvard Health blog further explains that following such a restrictive diet without a doctor's advice could lead to nutritional deficiencies.

The Blood Type Diet vs. Evidence-Based Nutrition


Aspect	Blood Type O Diet Recommendations	Scientific Nutritional Recommendations
Protein	Emphasizes a high intake of lean meats, poultry, and fish.	Advises moderate protein intake from a variety of sources, including plant-based ones.
Red Meat	Encourages lean red meat, including beef and lamb, as a staple.	Recommends limiting red meat consumption, especially processed and fatty types, to reduce health risks.
Grains	Heavily restricts or avoids grains like wheat and corn.	Encourages consuming a variety of whole grains for fiber and nutrients.
Dairy	Advised to avoid or strictly limit most dairy products.	Recommends low-fat dairy or fortified alternatives as a source of calcium and Vitamin D.
Weight Loss	Claims it can promote weight loss by avoiding certain foods and eating high protein.	Promotes weight loss through a balanced, calorie-controlled diet combined with regular exercise.
Scientific Basis	Based on evolutionary and lectin theories lacking robust scientific proof.	Grounded in decades of research on macronutrients, vitamins, and minerals.

Making Your Nutritional Choices

Ultimately, deciding on a diet requires considering various factors beyond blood type. While the blood type diet's focus on lean protein and unprocessed foods is a positive, its restrictive nature and lack of scientific backing make it a risky choice for some individuals. Consulting with a healthcare provider or a registered dietitian is always the best approach to developing a personalized eating plan that meets your specific health needs.

For more information on evidence-based nutrition, consider resources that focus on established dietary guidelines from reputable sources. It is crucial to remember that a balanced diet and regular exercise are the most proven path to overall health. A study published in PLoS ONE found that people following a specific blood type diet showed improved health markers, but this happened regardless of their actual blood type, suggesting the general healthfulness of the food choices was the key factor, not the blood type itself.

Conclusion: Prioritizing Health Over Hypothesis

When considering what type of meat is good for O-positive, the answer depends on whether you follow the blood type diet theory or evidence-based nutritional science. Adherents of the blood type diet suggest lean red meats, poultry, and fatty fish are beneficial, while discouraging pork and certain other options. However, the vast majority of scientific and health organizations do not endorse this diet due to the lack of evidence. The positive outcomes reported by some followers are more likely attributable to the diet's emphasis on whole foods and exercise rather than any specific interaction with their blood type. For optimal health, a well-balanced, varied, and evidence-based diet is the most reliable strategy, in consultation with a health professional.

Frequently Asked Questions

The theory, proposed by naturopath Peter D'Adamo, suggests that type O blood evolved from hunter-gatherer ancestors who thrived on high-protein diets. He claims that type O individuals have a digestive system better suited to processing meat efficiently.

No, extensive scientific reviews have found no evidence to support the effectiveness or health benefits of eating according to your blood type. The diet is largely considered a nutrition myth.

According to the blood type diet, lean meats like beef, lamb, venison, chicken, and turkey are considered beneficial. Grass-fed and organic options are often preferred by proponents.

Fish rich in omega-3 fatty acids, such as salmon, mackerel, and sardines, are recommended for those following the diet.

Yes, proponents of the diet advise against eating pork and goose. Specific seafood to avoid includes catfish, caviar, and pickled herring.

Any reported health improvements are likely a result of the diet's emphasis on whole foods and a reduction in processed foods and junk food, rather than the blood type-specific restrictions.

A balanced, varied diet that includes a mix of lean proteins, fruits, vegetables, and whole grains, without unnecessary restrictions, is a scientifically-backed approach. Consulting a dietitian can help create a personalized plan.