This Is What Happens to Your Body When You Eat Too Much Protein

Sure, plenty of people lose weight on a high-protein diet and it's true that the macronutrient can help you achieve your fat-loss goals. But like with anything, it's possible to go overboard.

"If you enjoy more protein than your body needs and you are exercising daily, it may be stored for energy depending on your level of activity," Adam Perlman, MD, PH, an integrative health and wellbeing expert at Duke University, told POPSUGAR. "On the other hand, excess protein may also be stored in the body as fat while the surplus of amino acids is excreted. The idea behind this is that you can't store extra amino acids or protein indefinitely, and if you consume too many calories and you don't burn them off with activity, you will gain weight."

For most people with normal functioning kidneys, eating too much protein shouldn't be an issue. But for those with an existing disease, it could be problematic.

When your body metabolizes protein, it produces ammonia, which is turned into a compound called urea. The urea is carried to the kidneys via the blood where it is eliminated in the urine, explained Kristin Koskinen, RDN, LD, CD. If you have a diseased kidney, it may not be able to handle the increase in urea, which can lead to urea build up.

Koskinen explained that while most healthy adults are able to metabolize protein even at levels that exceed the recommended daily amount, it could be dangerous for someone with a bad liver. To make matters worse, people could have liver damage and not even realise it — non-alcoholic fatty liver disease (NAFLD), which is strongly linked to obesity, affects up to 30 percent of Americans and is largely unsymptomatic until it's detected during a medical exam (via blood work, ultrasound, or radiologic study). It can lead to non-alcoholic steatohepatitis and even cirrhosis.

With a bad liver, eating too much protein can cause a build-up of ammonia. "Ammonia is toxic and will build up if your body can't process an overload of protein or eliminate urea," Koskinen said. "Ammonia in the blood stream can present itself as memory loss, confusion, or forgetfulness. A liver that is diseased with the silent NAFLD may not be able to keep up with the demands of the detoxifying process."

So while losing weight may lower your risk of NAFLD, doing so with a high-protein diet could be dangerous. If you think you may have NAFLD, make sure you visit your doctor to get tested. And as always, visit with a registered dietitian before making any major dietary changes.

A diet that's high in protein may be lacking in fibre, which is found in fruits, veggies, and whole grains. Not only does fibre keep you full, but it also keeps you regular. Also, some protein powders could cause this reaction in people explained Dr. Perlman, depending on the type of protein and sugars that are used.

To solve this, make sure you are using a protein powder that has added fibre or that you are actively adding more fibre to your diet with beans, whole grains, nuts, and veggies. In a pinch, a fibre supplement such as Metamucil could work, too.