I Stopped Eating for My Blood Type for 1 Week

For years, I followed the Blood Type Diet, eating plan that claims your blood type (A, B, AB, or O) determines which foods are best for your health.

Proponents say it improves digestion, energy, and even helps with weight loss.

I was a believer—until I decided to take a break.

For just one week, I ditched the rules and ate whatever I wanted.

And guess what?

All my old problems came rushing back. 

Here’s what happened.

The Blood Type Diet, suggests that:

• Type O should eat high-protein (meat, fish, veggies) and avoid grains & dairy.

• Type A should go vegetarian, avoiding meat and dairy.

• Type B can eat a varied diet but should avoid chicken, corn, and wheat.

• Type AB is a mix of A and B recommendations.

I’m Type O, so my diet was heavy on lean meats, vegetables, and healthy fats, while avoiding wheat, dairy, and processed foods.

I wanted to test if the diet really made a difference or if it was just a placebo. So, for 7 days, I ate:

• Bread, pasta, and pastries (which I normally avoided)

• Dairy (cheese, yogurt, milk)

• Processed snacks and sugary foods

• More carbs, less protein

Within two days, I felt bloated and sluggish. My stomach, which had been calm for years, started acting up, gas, discomfort, and irregular digestion. The Blood Type Diet had eliminated these problems, but now they were back with a vengeance.

I used to have steady energy throughout the day, but after eating refined carbs and sugar, I experienced energy spikes and crashes. By 3 PM, I was exhausted and craving more junk food.

My mental clarity took a hit. I felt foggy, irritable, and less focused. On my usual diet, my mind was sharp, now, I struggled with concentration.

My skin, which had been clear for years, started breaking out. Small pimples and redness appeared, something I hadn’t dealt with since before the Blood Type Diet.

I didn’t gain much in a week, but I felt puffier and less lean. My body clearly didn’t like the sudden influx of processed foods.

Some critics say the Blood Type Diet is pseudoscience, but my experiment proved (at least for me) that it works. Maybe not because of my blood type specifically, but because it eliminated inflammatory foods like gluten, dairy, and processed junk.

I’m back on the Blood Type Diet, not because of dogma, but because my body clearly thrives on it. If you’ve been following it and feel great, don’t dismiss it just because of critics. Listen to your body.