“It’s a hot macronutrient because it really does help you feel more full, which is what makes high-protein diets pretty effective for weight loss. The way protein is metabolised even increases your metabolism a little bit when you eat it,” says nutritionist Christy Brisette, the founder and president of 80 Twenty Nutrition.
But don’t get carried away: There may be health risks associated with having TOO much protein over a long period of time. Some research has shown that people on high-protein diets that are rich in red meats have higher levels of uric acid in their blood, which increases the risk of gout—a condition causing painful joint inflammation. A high-protein diet that’s also high in red meat has been linked to increased risk of colon cancer, according to the World Health Organisation, as well as kidney disease, according to one large 2016 study. And Brisette says people on high-protein diets may be more likely to be deficient in calcium and vitamin D, which increases the risk of osteoporosis later in life.
You need at least 0.8 grams of protein per kilogram of body weight per day, with very active people needing in the range of 1.2 to 1.8 grams per kilogram. At the very most, Brisette says, you should get two grams of protein per kilogram of body weight (that’s about 118 grams of protein for a 58 kilogram person).
“If you get more, you don’t see benefits and there could be risks,” she says.
Think your protein intake could be making you feel bad? Here are a few symptoms your high-protein diet isn’t working for you:
FEELING SUPER THIRSTY
When you eat excess protein, your kidneys have to work doubly hard to flush it out through your urine, and that can make you feel extra thirsty, says Brisette. Because they’re peeing more often and wasting more sodium, potassium, and magnesium, “people on high-protein low-carb diets tend to need more of these electrolytes,” she says. Fruits and veggies, as well as beans, legumes, and whole grains, are important sources for potassium and magnesium, so make sure you’re eating them on the regular.
CONSTIPATION OR DIARRHOEA
“If you cut out all whole grains, nuts, seeds, veggies, and fruit, all of which are good sources of fibre, it can lead to issues with digestion including constipation,” says Brisette. High-protein, low-carb diets can also wipe out healthy gut bacteria because you’re not getting enough prebiotics—a type of fibre that fuels healthy bacteria. “Sometimes if gut flora are out of whack, it can lead to bowel irregularities including diarrhoea or alternating diarrhoea and constipation, and you might experience some bloating and cramping,” she says.
To combat constipation, Brisette suggests adding in at least a serving of prebiotic foods to your day, including asparagus, apples, bananas, whole wheat, barley, oats, onions, and garlic. For other digestive woes, she suggests including a serving of sauerkraut, kefir, and kombucha in your diet once daily; if you don’t enjoy fermented foods, consider taking a supplement.
If going on a high-protein diet entails cutting out all carbs, including prebiotic sources, it could impact your mood in the long-term. “If you aren’t correcting imbalances in your gut bacteria, research links your gut microbiota to mental health, depression and anxiety,” says Brisette. And while some people feel energised on a high-protein diet, it can cause others to feel crabby and sluggish. “Carb-rich foods increase levels of serotonin in your brain, which is a happy neurotransmitter,” says Brisette. “By not getting enough carbs, certain people will notice a change in their mood and outlook.”
If you’ve got a case of the grumpies, Brisette suggests slowing add back in healthy sources of “slow carbs”—like half a sweet potato, half a cup of brown rice, or a couple pieces of lower-sugar fruit (like apples, peaches, pears and berries) every day. “People feel so much better when they do,” says Brisette.
Another not-so-great potential impact of low-carb diets: Research has shown that throwing off the healthy balance of gut bacteria can lead to weight gain. What’s more, Brisette says that she’s noticed sometimes when clients excessively cut back on carbs, their bodies hold onto excess weight. By adding back in healthy sources of carbs, “their bodies go out of starvation mode, and clients often drop stubborn weight,” she says.
Another common mistake that can lead to weight gain is focusing so much on protein that you overdo it on calories. “Clients might increase the portion size of their chicken or fish and add protein supplements to all their meals or snacks. They’re adding without removing something else, so they’re getting more calories than they’re burning,” says Bristte. That excess protein, she explains, can be stored as fat just like other macronutrients.
If you’re on a super low-carb (ketogenic) diet, bad breath is a common sign of ketosis—where your body has churned through all your stored carbs (a.k.a. glycogen) and is primarily burning fat for energy. “You really have to be avoiding carbs for your body to switch over into ketosis,” says Brisette. “It’s definitely something you undergo with a specific goal of burning extra fat. Over the short term, it can work for some people.” However keep in mind that going into ketosis can be dangerous if you have other health conditions where you need to keep your carb intake consistent, like diabetes or pregnancy, so be sure to talk to your doctor before going on a ketogenic diet.
CHANGES IN YOUR MENSTRUAL CYCLE
If you’re trying to get pregnant, going into ketosis for too long could cause your cycles to become irregular—or you could stop getting your period entirely. That’s because you can burn through too many fat stores, which can change your metabolism in a way that impacts your hormone levels and fertility. “Your body is going into preservation mode. It’s a sign your body is under stress, and it isn’t good time to bring baby into world because food is scarce,” says Brisette. “Women need a certain amount of fat for hormone levels for fertility and overall health, and ketosis can cause alarm bells to go off.” Any time your period suddenly goes MIA or becomes irregular when it used to run like clockwork, check in with your doctor ASAP.
HOW TO KEEP YOUR PROTEIN INTAKE HEALTHY
Now, all of the above shouldn't necessarily discourage you from eating more protein. But if you're looking to explore a more extreme high-protein eating plan, here are some things to keep in mind to avoid any negative consequences:
See your doctor first. Before you go on high-protein diet, Brisette recommends checking in with your doctor. “You may get screened to be sure you’re not at higher risk of kidney disease,” she says. Some people are genetically more susceptible, which could make a very high-protein diet riskier.
Be aware of your protein sources. Most of the issues with high-protein diets have been linked to eating lots of red meat. So try to get about 50 percent of your daily protein from plant-based proteins (like beans, lentils, nuts and seeds) and 50 percent from healthier animal sources (poultry, fish, Greek yogurt, cottage cheese, and leaner meats).
Spread your protein throughout the day. Your body can only process 30 grams of protein per meal. “More than that and you’re wasting the protein. Your body’s ability to convert it into muscle caps out,” says Brisette. If you’re aiming for 100 grams of protein a day, don’t try and squeeze most of it in into one or two meals. Instead, spread your protein intake evenly throughout the day, aiming for 20 to 30 grams per meal, and filling in the rest at snack times. That includes breakfast, when Brisette says most women have a hard time meeting their protein goals. (Try these 14 high-protein breakfasts.)
Don’t forget to eat your greens. No matter your diet, nutritionists agree it should always include plenty of veggies, which contain fibre, vitamins, and antioxidants that you just can’t get from meats and other protein sources. “If you’re trying to get 30 grams of protein at each meals that’s fine, but if you’re also trying to cut out carbs based on trends, I’d prefer you go for a Mediterranean-style or a whole, plant-based foods diet,” says Brisette.
Ultimately, your best bet is usually to have a balanced diet that doesn’t cut out—or highly emphasize—entire food groups. “A lot of research about high-protein diets is short-term. We don’t know for sure there aren’t long-term risks. And I don’t want my clients to be guinea pigs,” says Brisette.
This article originally appeared on Women's Health US