Being Blood Type O, and Eating to Maximize My Blood Type

In my efforts to work with my genetics in order to create a constant and sustainable state of peak performance, I’ve done many experiments with my diet over the past three years.

Eating a diet comprised of mainly vegetables and meat has given me the greatest performance.

Recently, I heard of the Carnivore Diet (a meat-centric version of Keto), which really intrigues me.

In order to further solidify my understanding of whyeating this way makes me feel so good, I’m returning to a book I read this past year: Eat Right 4 Your Type: The Individualized Blood Type Diet Solution by Peter D’Adamo.

The book takes an anthropological approach toward clarifying why people with different blood types will respond to different foods in different ways.

Peter D’Adamo, author of the book, claims that people with the “O” blood type respond best to a diet comprised mainly of meats and vegetables.

My intention with this post is simply to take some notes about what the book says about O blood types, so that I can understand myself better and leverage this information to KICK MAXIMUM AMOUNTS OF ASS, BABY!

Lol. Here we go.

Reading Notes:

The Basics of Type-O: “The Hunter”

Meat EaterHardy Digestive TractOveractive Immune SystemIntolerant to dietary and environmental adaptationsResponds best to stress with intense physical activityRequires an efficient metabolism to stay lean and energetic


Type O: The most widespread early mutation and most basic blood type, the survivor at the top of the food chain, with a strong and ornery immune system willing to and capable of destroying anyone, friend or foe


Type O thrives on intense physical exercise and animal protein. The digestive tract of Type O retains the memory of ancient times. The high-protein hunter-gatherer diet and the enormous physical demands placed on the system of early Type Os probably kept most primitive humans in a mild state of ketosis.

The combination of ketosis, calorie deprivation, and constant physical activity made for a lean, mean hunting machine – the key to the survival of the human race.


Your genetic inheritance offers you the opportunity to be strong, lean, productive, long-lived, and tenacious. 

When a Type O’s wiring gets crossed, as a result of a poor diet, lack of exercise, unhealthy behaviors, or elevated stress levels, you’re more vulnerable to negative metabolic effects, including insulin resistance, sluggish thyroid activity, and weight gain. As a Blood Type O, you may also be predisposed to certain illnesses, such as thyroid disorders, which can impact weight control. It is not uncommon for Type O to experience thyroid instability, and you often exhibit insufficient levels of iodine, an element critical for proper thyroid activity. Imbalanced thyroid function can cause many negative health effects such as weight gain, fluid retention, hair loss, and fatigue.

I’m going to stop right here and just say that my thyroid has alwaysbeen a pain point – I’ve leaned towards the hypothyroid end of the spectrum for as long as I can remember. It’s something I’ve band-aided by using therapeutic doses of NDT (natural desiccated thyroid), but it’s interesting to read it clarified as something someone with my blood type is predisposed to. Anyways, back to it…

The key to your optimal diet is embedded in the historical imprint of your blood type.Blood Type O is wired for action, and this quality is reflected in your metabolism, your digestion, and your immune system. When you eat a diet of lean, chemical-free meats and healthy fruits and vegetables, your body maintains a lean physique and you have lots of energy.

You will succeed by incorporating plenty of high-quality protein in your diet. This increases active tissue mass and raises your metabolic rate. A high-protein diet will boost your weight loss and burn off any excess fat.

How can Blood Type O lose weight by eating meat? The secret is in your genetic memory of the Paleolithic paradise. Your genetic ancestors’ reliance on meat, an early key to the survival of the species, is coded into a variety of genes controlled by your blood type. You possess a secret weapon not available to all blood types: higher levels of stomach acid that allow you to efficiently digest and metabolize meats and fats. In particular, you have three times the normal level of an enzyme called intestinal alkaline phosphatase, which helps break down protein and fat, allowing for easier digestion and metabolism.

Your Blood Type O ancestors’ primary path to survival depended on maintaining a high state of active tissue mass and a low percentage of body fat. That’s your nature as well – as long as you maintain the right diet for your type. You are vulnerable to insulin resistance and weight gain when you veer from this path, eating foods with dietary lectins that prevent their being used as a source of energy. These foods signal your body to send those calories to the storage shed and lock the door to utilization. The result is that your energy levels become depleted, and stored fat causes fluid retention and a sluggish metabolism.


Type Os are leaner when their muscle tissues are in a state of slight metabolic acidity. In this state, they use calories more rapidly.

Blood Type O also has a tendency to have low thyroid hormone, a condition called hypothyroidism. This can result from imbalances in your gut flora – your microbiome. Excessive levels of yeast (Candida) overgrowth or certain strains of non-blood-type-friendly bacteria in the gut can actually cause the immune system to attack the thyroid by mistake. I’ve seen many cases of autoimmune thyroid disease resolved in Type O patients by a simple change in diet. The Type O diet features foods that support thyroid function and discourage the growth of antagonistic bacteria in the gut.


Type O individuals also have a tendency toward inflammatory conditions. The reasons are not completely understood, but may have to do with their double barreled anti-blood-type antibodies, or as previously discussed, imbalances in their microbiome. Scientists have found that inflammation is directly related to weight gain in that it compromises the hormone leptin, which is respondible for energy balance. So a Type O weight loss plan is also an anti-inflammatory plan.


Short Term Stress, Catecholamines/Neurotransmitters (page 82)

Studies have shown that Type O has a stress response that centers on fight-or-flight.The reasons are a bit complicated, so I’ll describe it simply here. Dopamine is a major neurotransmitter made by the brain that plays an important role as a chemical messenger and central element in what is called the brain’s reward-motivae=ted behavior. Most types of rewards increase the level of dopamine in the brain, and most addictive drugs increase dopamine activity and levels. Dopamine is converted to another neurotransmitter, called norepinephrine (also known as noradrenaline), by an enzyme known as dopamine beta-hydroxylase (DBH).

You can visualize this as two buckets, one high, one low, connected by a tube. The upper bucket is dopamine, the lower bucket norepinephrine, the tube connecting them is DBH. If you’re Type O you have a very, very large tube (a lot of DBH), which means that under stress lots of dopamine flows from the upper bucket to the lower one (norepinephrine). Dopamine tends to make us happy and content while norepinephrine tends to make us anxious and prepared for fight-or-flight. A surprising amount of norepinephrine is made in the gut where, in excess, it can disrupt digestion and assimilation and even the balance of flora.

So under even mild stress, Type O will have to work harder at maintaining dopamine and blunting norepinephrine.Fortunately, there are lifestyle and dietary habits that can accomplish this. For example, vigorous exercise tends to block DBH and narrow the tube a bit, as does a high-protein diet. Wheat, unfortunately, tends to widen the tube, draining dopamine and causing the norepinephrine bucket to overflow.

The higher level of catecholamines can increase feelings of anger and aggression, perhaps explaining why ironically “Type A behavior” is in fact associated with Type O blood.

Stress is not in itself the problem; it’s how your body responds to stress. As a Type O, you want to do whatever you can to increase dopamine(and its accompanying feelings of satisfaction and well-being) and decrease norepinephrine (and its accompanying feelings of anxiety and stress).The ability to reverse the negative effects of stress lives in your blood type. Healthy Type Os are meant to release the built-up hormonal forces through vigorous and intense physical exercise. Your sytem is literally suited for it. If you are Type O, you have the immediate and physical response of our hunter ancestors. Your blood type carries a patterned alarm response that permits explosions of intense physical energy.

When you encounter stress, your body takes over. As your adrenal glands pump their chemicals into your bloodstream, you become tremendously charged up. Given a physical release at this time, any bad stress you are experiencing may be converted into a positive experience.

Exercise is especially critical to the health of Type O, because the impact of stress is direct and physical. Not only does a regular intense exercise program elevate your spirits, it enables Type O to maintain weight control, emotional balance, and a strong self-image.

Type Os who do not express their physical natures with appropriate activity in response to stress are eventually overwhelmed during the exhaustion stage of the stress response.This exhaustion stage is characterized by a variety of psychological manifestations caused by a slower rate of metabolism, such as depression, fatigue, or insomnia. If there is no change, you will leave yourself vulnerable to a number of inflammatory and autoimmune disorders, type 2 diabetes, consistent weight gain, and eventual obesity.

Remember, your goal is to counter stress with action. For Type O, the best antidote to fatigue and depression is physical work. Think of your metabolism as a fire.You start a fire first by using little pieces of wood called kindling, and then gradually add larger and larger pieces of wood until you have an inferno.

On Personality

Depression (both unipolar and bipolar) is in part associated with low dopamine levels and has been shown to be more common in Type O.

The belief that personality is determined by one’s blood type is held in high regard in Japan. Termed ketsuekigata, Japanese blood type analysis is serious business. Corporate managers use it to hire workers, market researchers use it to predict buying habits, and many people use it to choose friends, romantic partners, and lifetime mates. Vending machines that offer on-the-spot blood type analysis are widespread in train stations, department stores, restaurants, and other public places. There is even a highly respected organization, the ABO Society, dedicated to helping individuals and organizations make the right decisions, consistent with blood type.

The idea that your blood type may relate to your personality is not really so strange. Indeed, if you look at each of the blood types, you can see a distinct personality emerging – the inheritance of our ancestral strengths.

On Candidiasis

The Candida organism appears to use its own lectins to attach to cells by binding to the sugar fucose. Fucose is the antigen of Type O, and it is perhaps not surprising that studies have shown that Type O carries more candida than the other blood types. Perhaps because of this, Type O tends to develop more of an allergic-type hypersensitivity to the candidiasis organism, especially when eating too many grains. this has been the basis of a theory called the yeast syndrome and a variety of candida diets. These diets stress high protein intake and the avoidance of grains, but they tend to be generalized across blood types, when it is only Type O who appears to have this yeast sensitivity.

On Chronic Fatigue Syndrome and Licorice

In recent years, I have treaded many people who suffered from the baffling disease called chronic fatigue syndrome (CFS). The primary symptom is great tiredness. The most important thing I’ve learned from my research and clinical work is that CFS may not be an exclusively autoimmune disease at all, but rather a detoxification issue, caused by poor liver metabolism and the inability to neutralize harmful chemicals. To my reasoning, only this sort of liver problem could produce immunological effects as well as effects characteristic of other systems, such as digestive or musculoskeletal.

I’ve found that Type O CFS patients in particular do very well on licorice and potassium supplements,in addition to the blood type diet. Licorice has many effects in the body, but in the liver it really shines. The bile ducts, where detoxification occurs, become more efficient, offering greater protection against chemical damage. This preliminary removal of stress to the liver seems to positively influence the adrenals and blood sugar, increasing energy and producing a feeling of wellbeing.

Fascinating stuff.

I’ll be looking into liver supplements. I suspect that D’Adamo hit the nail on the head with his point about CFS being linked to inefficient liver metabolism – my liver has been a pain point, and the many different supplements I’ve used that target and support liver function (especially uridine, NAC, and glutathione) have made the biggest impact in my fatigue, digestion, etc.

I’m especially fascinated by the connection between Type Os and the dopaminergic system within the brain. I can say for sure that when I’ve been honoring my Type O nature with my diet and exercise habits, dopaminergic activity in my brain is at its height, and I feel the most in control and most powerful.

I’m going to explore the dopamine system in my next blog post, and what the book The Edge Effect by Dr. Eric Braverman has to say about it.