Odds are you’ve eaten plenty of animal-based proteins throughout your fitness journey, and more likely than not it’s been in the form of animal flesh — chicken breasts, ground beef, bison, and so on. But have you ever given thought to eating what’s inside the animal? While that may sound unappetizing, hear us out for a second.

Organ meats, such as chicken livers or beef heart, are nutrient-dense sources of food that have been consumed for countless years.

“Liver is like nutritional gold,” says Gabrielle Lyon, D.O., a functional medicine physician specializing in muscle-centric medicine. “It has high amounts of iron, Vitamin A and bio-available zinc. This is important because it’s not just what you consume that matters — it’s what you absorb that counts.”

For those who may not know, bioavailability refers to how much of a macro or micronutrient can actually be absorbed by our body. This is one of the common problems with plant proteins — only 60-80 percent of those proteins are utilized by our body, depending on the source, compared to 90 percent and up for animal proteins.

In other words, you’re getting more bang for your buck with organ meats. In 3.5 ounces (100 grams) of cooked beef liver alone you’re getting the following:

  • Protein: 27 grams
  • Vitamin B12: 1,386% of the RDI (Recommended Daily Intake)
  • Copper: 730% of the RDI
  • Vitamin A: 522% of the RDI
  • Riboflavin: 201% of the RDI
  • Niacin: 87% of the RDI
  • Vitamin B6: 51% of the RDI

All of that will only set you back 175 calories.

Beef heart is another great source of micronutrients, specifically with CoQ10. “CoQ10 has been shown to reduce blood pressure and improve arterial health,” Lyon says.

And kidneys are rich in the micronutrients selenium and Vitamin B12, Lyon points out, both of which are vital for overall cell health.

Oh, and a message for any of your vegan friends who might give you crap for eating organ meats — a 2019 study out of Germany actually found that if people ate organ meats once or twice a week livestock emissions and the number of animals that would be killed annually would actually decrease. In fact, the researchers wrote that the introduction of organ meats to people’s diets provides “a tremendous opportunity for sustainably feeding the planet by 2050.”

Just another reason why you should eat your heart out — or the animal’s heart out. You know what we mean.

We understand, though, if you’re not chomping at the bit to start chomping down on some kidneys or liver—doesn’t sound quite as appetizing as a juicy steak. But Lyon has some tips for you.

“I’d recommend cooking beef heart in some ground beef,” she says, “or chicken livers in ground chicken.” This way, you’re getting all the benefits of the organ meat but enjoying a taste you’re familiar with. On her Instagram, Lyon also recommends blood sausage if you want to go savage with it.