What happens when you eat too much meat?

You’ve probably heard varying opinions on whether eating meat is good or bad for you. Although the right answer is still very murky, experts and researchers have found that eating too much meat can worsen your risk for several health issues. Here are some things that could happen to your body if you eat too much meat.

You could feel sleepy

Protein has a reputation for providing energy that lasts, so you might be surprised when a meat-heavy diet leaves you dragging. While protein sticks with you because it takes a while to digest, it won’t give you the immediate boost that carbohydrates do: carbs quickly break down into the body’s most readily available energy source, glucose, says registered dietitian, Caroline Passerrello.

Because your brain can only use glucose for energy, its energy supply can lag when your diet features slow-to-digest protein. The fuel is “taking a little longer to get to your brain, so you’re a little less focused,” says Passerrello. The same is true for muscles, which also run on glucose, she points out. The result: fatigue and brain fog.

Your hair and skin might not look their best

If you’re overdoing your meat portions, there’s a good chance you’re skimping on other food groups. Vitamin C is rarely found in animal products, so if you’re eating meat in place of produce, you could become deficient. Vitamin C plays a role in forming collagen, a protein that gives structure to skin, hair, nails, bones, and more. If you’re deficient, you might notice changes in your body, says registered dietitian Jenna Braddock, founder of “Your skin could be rough and bumpy. You might see some interesting body hair growth,” she says.

Passerrello adds that her clients have raved about how much better their skin looks after cutting back on animal products to make room for a more plant-based diet. Braddock recommends eating dark, leafy greens every day – a cup of kale alone packs in more than a day’s worth of vitamin C.

You could get sick more often

Your skin isn’t the only place you’ll see a vitamin C deficiency. If you feel like you can’t beat a cold, you might want to tweak your eating habits. “If you’re on a keto diet, you’re probably not eating much fruit, which is one of the best sources of vitamin C,” says Braddock. Luckily, you can get the nutrients you need from vegetables, too, like broccoli and capsicum.

You could get constipated

Meat has hardly any fibre, which you’d normally get from fruits, veggies, and whole grains. Constipation and painful bowel movements are some of the first signs you’re lacking in fibre, says Braddock. Get your system regular again by adding healthy carbs like whole grains or – better yet – fruits and veggies. “Going back to fruits and vegetables is one of the best ways to get fibre because you’re also getting really wonderful nutrients along with it,” says Braddock.

Your heart could be in danger

Another benefit of fibre is that it helps keep your body from absorbing cholesterol, and that can protect your heart. If your meat choices are red and processed meats – especially at the expense of produce, whole grains, and other fibre sources – the toll on your heart is even worse. Those types of meats are high in saturated fats, which research suggests raises ‘bad’ LDL cholesterol and, in turn, raises the risk of heart disease.

Braddock points out research in the Annals of Internal Medicine that questions whether all saturated fats are unhealthy, but the evidence on processed meat like salami, hot dogs, and bacon is pretty grim – these choices are clearly hard on the heart. The Australian Department of Health recommends less than 10 per cent of the total energy (kilojoules) you take in should come from saturated fat.

Your body might have to battle inflammation

The saturated fats in meat can boost inflammation in the body, research in the European Journal of Nutrition found. Plus, meat is severely lacking in inflammation-fighting antioxidants compared to produce. “The reason there’s a recommendation for people to ‘eat a colourful diet’ is each of those colours you find in fruits and vegetables as pigments is a different group of antioxidants that do different things and benefit the body in different ways,” says Braddock.

To make sure you’re getting enough, she recommends adding one extra fruit or vegetable every day. Set a goal of having at least two cups at dinner and lunch, one cup at breakfast, and extras as snacks, she says.

You’re more likely to develop kidney stones

Excessive protein can take a toll on your kidneys. Specifically, animal-based proteins are full of compounds called purines, which break down into uric acid; too much uric acid increases the risk of kidney stones, says Passerrello. Most people shouldn’t have too much trouble breaking down the proteins, she says, but watch your intake if you have a family history of kidney trouble.

You might gain weight

You’ve probably heard that protein is the ultimate tool in translating your work at the gym to the toned body you want. While it’s true that the body relies on protein for rebuilding muscle, too much can have an undesired side effect: “If you eat more protein than what your body needs, you don’t store it as protein – you store it as fat,” says Braddock. “It’s not beneficial unless you’re also increasing your body’s demand.”

Your cancer risk could increase

Studies show that eating a lot of red meat could increase your chance of colorectal cancer.  The 2018 report, Diet, Nutrition, Physical Activity, and Cancer: A Global Perspective from the World Cancer Research Fund found that eating more than 500 grams of red meat a week could raise the risk of colorectal cancer.

In fact, eating processed meat regularly in any amount can leave you more vulnerable to stomach and colorectal cancers. Scientists haven’t confirmed the reason for that link, but it might be connected with the saturated fats in those products, says Passerrello. Try swapping some beef, pork, and processed meats for poultry or plant-based proteins like legumes.

You might become dehydrated

Thanks to the increase in uric acid from processing those proteins, you might notice you’re extra thirsty on a meat-heavy diet. “The kidneys do need more water to dilute those toxic waste products,” says Passerrello. “To produce that urine, we need to pull [water] out of our bodies.” That could leave you dehydrated if you aren’t careful, so make sure you sip plenty of water to make up for it.

You could contribute to climate change

Even if you aren’t worried about your health risk, there’s another reason you might want to cut back on meat: the environment. By cutting out all or some meat and replacing those kilojoules with fruits and vegetables, you could play a part in reducing greenhouse gases. “Even by slightly reducing your animal protein consumption, you can help eat a little more sustainably,” says Braddock.