Clinically reviewed by Dr. Ponlawat Pitsuwan, Physician, Doctor Bangkok. Last reviewed: August 2026
The blood type B diet recommends eating lamb, fish, dairy, and most vegetables while avoiding chicken, corn, wheat, and peanuts. It was popularised by Dr. Peter D’Adamo in his book Eat Right for Your Type. Current evidence does not confirm the diet works specifically because of blood type, but many of its food choices align with broadly healthy eating patterns that do have support.
If you have recently found out you are blood type B, or someone told you that your blood type should determine what you eat, you are probably trying to figure out whether any of this is real. That is a fair question, and I want to give you an honest answer rather than a sales pitch for either side.
The blood type B diet has a following, especially among expats here in Bangkok who are already health-conscious and exploring personalised nutrition. What I tell patients who ask me about it is this: some of the food choices are genuinely healthy, the science behind the blood-type-specific claims is weak, and if you are going to follow any restrictive eating plan, it is worth knowing what nutritional gaps to watch for.
What Is the Blood Type B Diet?
This diet comes from a book called Eat Right for Your Type, written by Dr. Peter D’Adamo and published in 1996. His idea was that your ABO blood group influences how your body reacts to certain foods. For type B specifically, he argued that proteins in certain foods react badly with type B blood, disrupting digestion and metabolism.
That is the foundation of why the diet tells you to eat some foods and avoid others. Whether it holds up to scrutiny is a separate question, which I will get to below.
Blood Type B Foods to Eat and Foods to Avoid
Foods the Diet Recommends for Type B
The diet puts lamb, venison, and rabbit at the top of the protein list. Fish is broadly encouraged. Dairy is one of the more unusual features here: type B is the only blood group for which D’Adamo recommends goat milk, mozzarella, and feta as beneficial. Most vegetables are fine, particularly leafy greens, broccoli, sweet potato, and carrots.
Eggs are listed as neutral to beneficial. Brown rice and oats are generally acceptable. Olive oil is the preferred cooking fat.
Foods the Diet Says Type B Should Avoid
The avoid list is where things get practically complicated, especially in Bangkok. Chicken is the biggest one. D’Adamo claims a specific protein in chicken disrupts type B metabolism. This surprises most people, since chicken is widely seen as the healthy lean protein.
Corn, wheat, lentils, and peanuts are also on the avoid list, along with buckwheat. For anyone eating Thai food daily, this creates real challenges. Pad thai has peanuts. Khao man gai is boiled chicken on rice. Many street food dishes use corn or wheat-based noodles.
| Category | Beneficial | Avoid |
|---|---|---|
| Meat | Lamb, venison, rabbit | Chicken, pork, duck |
| Seafood | Salmon, sardines, cod, sole | Shrimp, crab, lobster |
| Dairy | Goat milk, mozzarella, feta, kefir | Blue cheese, ice cream |
| Grains | Brown rice, oats, millet | Wheat, corn, buckwheat, rye |
| Vegetables | Leafy greens, sweet potato, broccoli | Tomatoes, corn, avocado |
| Legumes | Kidney beans, lima beans | Lentils, peanuts, chickpeas |
| Oils | Olive oil | Sesame oil, sunflower oil |
What the Research Actually Says
Here is the honest version: the clinical evidence for blood-type-specific dietary benefits is limited.
A study published in PLOS ONE in 2014, which looked at over 1,400 participants, found that the food patterns linked to each blood type diet did produce some health benefits. But those benefits appeared in people of all blood types, not just the matching one. The diet was doing something, but not because of blood type.
What I tell patients is this: if following the type B food list leads you to eat more vegetables, fish, and lamb instead of processed food, you will likely feel better. That improvement is probably down to eating well, not your blood type.
Eating the Blood Type B Diet in Bangkok
Bangkok makes this diet both easier and harder than most cities. Easier, because fresh fish, lamb, and good quality dairy are all accessible. Harder, because chicken is everywhere, peanuts appear in almost everything, and avoiding wheat or corn in street food requires real effort.
If you eat at Thai restaurants, beef and fish dishes are your best options. Tom kha with fish works well. A simple fish with ginger stir fry is easy to find and fits the guidelines. Many central Bangkok restaurants will accommodate requests to leave out peanuts or swap proteins.
For the office lunch crowd eating from street stalls, grilled fish with rice and vegetables is one of the easiest type B-compatible meals available. Look for pla tod (fried fish dishes) or beef options instead of the usual pad kra pao.
Supermarkets along Sukhumvit and around Asok carry goat milk, feta, and mozzarella. If you want lamb, Foodland at Asok and Villa Market stock it consistently.
Exercise Recommendations for Blood Type B
D’Adamo recommends moderate physical activity that balances exertion with mental focus. He suggests cycling, hiking, tennis, and yoga over intense competitive training. There is no independent clinical evidence supporting this specifically for blood type B. That said, balancing cardiovascular exercise with lower-stress activity is reasonable advice for most people.
If you are exercising in Bangkok’s heat and humidity, moderate intensity and good hydration matter far more than your blood type.
Nutritional Gaps and What to Watch For
This is the section most blood type B diet guides skip, and I think it matters most.
Avoiding chicken, peanuts, lentils, corn, and wheat removes a significant amount of accessible protein and fibre from most people’s diets. In Bangkok, where chicken is the dominant affordable protein, strict adherence can quietly reduce your intake of B vitamins, plant protein, and fibre without you realising it.
I recommend that anyone following this diet for more than a few weeks get a basic blood panel done. Iron, B12, vitamin D, and standard metabolic markers are worth checking. If you are cutting out legumes, make sure you are getting enough fibre from vegetables and whole grains instead.
This is not a reason to avoid the diet. It is a reason to monitor yourself rather than assume a food list automatically covers all your nutritional needs. At Doctor Bangkok, a general health check gives you a clear picture of where you actually stand.
When to See a Doctor About Your Diet
Most people do not need a doctor’s approval to eat more lamb and fewer peanuts. But if you are using the blood type B diet to manage a specific health goal, such as weight loss, fatigue, or digestive issues, those symptoms deserve a proper assessment.
I see patients regularly who have been following restrictive diets for months based on something they read online, while an underlying issue like a thyroid problem, iron deficiency, or insulin resistance goes unaddressed. The diet may even be masking the problem temporarily.
If you are in Bangkok and want to know your blood type, or have not had a health check recently, both are straightforward. A blood type test is fast and low-cost, and knowing your blood type matters for medical reasons well beyond diet, including emergency care and surgery.
Curious about your blood type or want a health check to see how your diet is actually affecting your body? Doctor Bangkok offers blood testing, general health screening, and medical consultations in central Bangkok, with English-speaking doctors and no referral needed. Walk in or book at doctorbangkok.co.th.
Can I follow the blood type B diet eating Thai food in Bangkok?
Yes, with some planning. Thai cuisine has good options: grilled fish, beef dishes, and vegetable curries all work well. The harder part is avoiding chicken, peanuts, and corn, which appear in a lot of street food staples. If you order carefully and ask for substitutions, it is manageable day to day.
Is the blood type B diet scientifically proven to work?
Not in the way D’Adamo claims. Current evidence does not confirm that dietary benefits are specific to your blood type. That said, many of the foods recommended for type B are genuinely healthy choices. The diet may help you feel better, but most likely because you are eating more whole foods, not because of your blood type.
Why should blood type B people avoid chicken?
According to D’Adamo’s theory, chicken contains a protein that specifically disrupts type B metabolism. This claim has not been validated in clinical trials. If you have been relying on chicken as your main protein and want to follow this diet in Bangkok, lamb, turkey, and fish are the recommended alternatives.
How do I find out my blood type in Bangkok?
A simple blood test at any private clinic will tell you quickly. At Doctor Bangkok, it is fast, affordable, and can be done as part of a broader health check. Knowing your blood type also matters beyond diet, for emergency situations, surgery, and transfusions.
What are the biggest nutritional risks of the blood type B diet?
Cutting out chicken, peanuts, lentils, corn, and wheat can reduce your fibre, plant protein, and B vitamin intake. In Bangkok where these foods are everywhere, the restrictions are more significant than they might seem. A basic blood panel every few months is a sensible precaution if you are following the diet strictly.
Does the blood type B diet help with weight loss?
Some people do lose weight following it, but evidence suggests this happens because the diet cuts processed food and refined grains, not because of anything blood-type-specific. Any eating plan that reduces junk food and increases whole foods tends to support weight management. The diet itself is not a validated weight loss intervention.
Can I follow the blood type B diet if I am vegetarian?
It becomes quite restrictive. The diet already limits lentils, peanuts, and chickpeas, which are staple vegetarian proteins. For vegetarians in Bangkok trying to follow type B guidelines, kidney beans, eggs, and certain dairy products would need to carry most of the protein load. Talking through your nutritional intake with a doctor before committing to this combination is a sensible step.
Dr. Ponlawat Pitsuwan
Physician, Doctor Bangkok
a private medical clinic in central Bangkok. He sees expats, residents, and medical tourists for general consultations, health screening, and nutrition-related concerns. His focus is straightforward, evidence-based care delivered in plain language.
Dr. Ponlawat Pitsuwan is a physician at Doctor Bangkok, a private clinic in central Bangkok. He sees expats, residents, and medical tourists for general medicine, wellness consultations, and IV therapy. His focus is straightforward, evidence-based care delivered in plain language.
