1. Your Breath Smells Funky
When you cut your carbs to the bare minimum (which you’re likely doing if you’re on a super-high-protein diet), your body enters a state called ketosis, where it starts burning fat for fuel instead of the usual carbohydrates. That might be great for weight loss, but not so much for your breath, says Jessica Cording, R.D. That’s because when your body burns fat, it also produces chemicals called ketones that can leave your mouth smelling sort of like you drank nail polish remover. The worst part? Since the stench is coming from inside you, brushing, flossing, or rinsing won’t make much of a difference.
2. YOU COULD
According to a study that followed thousands of adults for nearly 20 years, those who eat a diet rich in animal protein are four times as likely to die of cancer than those who follow a low-protein diet. And other findings back the finding: In another study of thousands of people, researchers found that high-protein dieters had up a 66 percent greater risk of death during the study period than those who ate less protein. So, go ahead and settle for being average. Seriously!
3. Your Mood Takes a Dive
Maybe the Hulk-sized bodybuilders at the gym are grunting because they’re working crazy-hard. Or maybe they’re just in a crappy mood. Your brain needs carbs in all their sugary, starchy glory to stimulate the production of the mood-regulating hormone serotonin. Strip them from your diet, and you’re more likely to feel grouchy, irritable, or just blah. And yes, science backs this up: One Australian study of overweight adults found that those who followed a strict low-carb diet for a year reported more crankiness compared to those who followed a higher-carb, low-fat diet—even though both groups lost roughly the same amount of weight.
4. You Gain Weight
A high-protein diet might help you drop pounds in the short-term. But if you’re going hard on the egg whites and whey protein without cutting out other stuff, you’re gonna gain weight, not lose it. In fact, one long-term study of more than 7,000 adults found that those who ate the most protein were 90 percent more likely to become overweight compared to people who ate less of the stuff. In other words, there’s still no such thing as a miracle food. Sorry, folks!
5. Heart Problems
Protein rich foods often contain quite a bit of cholesterol. Eating too much animal protein can cause buildup in the arteries of your heart, which puts you at risk for heart problems, including heart attacks and strokes.
6. Kidney Problems
Eating excess protein causes more nitrogen waste products to build up in your blood. Your kidneys will work overtime to remove this nitrogen, which puts more strain on kidneys and harms kidney function. Your body will need to use extra water to flush out the nitrogen, which can result in dehydration.
7. YOU’LL PACK
Not only will you gain weight—the majority of the weight will be in the form of flab. You know those abs you worked so hard to uncover? Kiss those goodbye. When you take in more protein than your body needs—many experts say that 30 grams are the max your body can handle per meal—the extra protein will likely be stored as fat, while the excess amino acids will simply be excreted.