With so many protein bars, shakes, and supplements on the market, it’s kind of been hammered into our heads that protein is the wonder nutrient.
It is an important building block for our cells, essential to repair old ones and build new ones. Which is why we think about it most commonly as a post-workout muscle-builder. Recent compelling studies have shown that a higher-protein diet may potentially help with weight management—particularly by helping us feel more satiated, and helping burn fat mass and maintain lean muscle. It also may have benefits for your heart. But the research is small and far from conclusive.
So how much protein should you eat? And can you ever eat too much? We talked to nutritionists and scoured studies to find out how much protein is healthy to pack into each day.
First of all, there’s no easy one-size-fits-all recommendation on how much protein you should get.
The current USDA Dietary Guidelines recommend protein make up somewhere between 10 and 35 percent of your daily calories (but some nutrition experts think 35 sounds really high). A lot of people automatically think of 2,000 calories a day as the standard, but that might not be right for you—you may be eating more or less depending on your weight, fitness level, weight loss goals, and if you’re pregnant.
“Your [ideal amount of protein] will vary based on caloric needs and whatever else you have going on,” Kristen F. Gradney, R.D., director of nutrition and metabolic services at Our Lady of the Lake Regional Medical Center and spokesperson for the Academy of Nutrition and Dietetics, tells SELF. “For example, if you work out and lift weights three or four days a week, you’re going to need a little more than somebody who doesn’t. It varies.”
You can also use the calculation from the Institute of Medicine, which says the Recommended Daily Allowance (RDA) of protein for adults should be 0.8 g/kg body weight. To calculate it, divide your weight in pounds by 2.2, then multiply by 0.8. “So for a 130-pound woman, that would be 47 grams of protein,” explains Jessica Fishman Levinson, R.D., founder of nutrition counseling company Nutritioulicious. For an even more personalized look at your protein needs, use this handy USDA nutrient calculator, which also takes into account your height and activity level.
Let’s be honest: all of the different calculations make it a bit confusing. But in the end, you’ll get a very similar result no matter which way you think about it. Just remember that your recommended grams means grams of protein in your food, not the serving size. So for example, a 4-ounce piece of sirloin steak has 24 grams of protein.
Complicated math aside, chances are you’re getting the right amount of protein without even thinking about it.
According to the 2015 USDA dietary guidelines committee, most people are getting just about (or just under) the recommended amount of “protein foods,” meaning meat, poultry, and eggs. Here’s the rub: “protein foods” doesn’t include dairy, soy, or grains, so if you’re eating those things (which you probably are), it’s likely you’re right in the middle of the recommendations without really trying.
Research published in the American Journal of Clinical Nutrition following a protein summit of over 60 nutrition experts found that the average American currently gets 16 percent of their daily calories from protein, but that we could eat more than that. The suggestion to increase protein intake isn’t widely accepted though, and more research needs to be done to determine if the benefits are enough to make sweeping recommendations.
There is a chance of overdoing it, and over time that can lead to some adverse health effects.
“You can always have too much of anything,” Levinson says. “But [overloading on protein] is more common in athletes and body builders, especially those who use protein powders multiple times a day in addition to the other protein they’re getting from their diet,” Levinson explains.
Most nutrients have a certain level that the average person can eat in a day before experiencing negative effects, called the “tolerable upper intake level.” Right now, there isn’t one that’s known for protein because we don’t have enough research to show what it would be.
Eating too much protein over time (months or years, depending on genetics) can lead to kidney problems, though. “Protein is a very big molecule that your body has to break down,” Gradney explains, so overloading puts unnecessary pressure on the kidneys. If your protein sources are animal-based, eating too much can also mean eating too many saturated fats, which can affect your heart and weight negatively.
Other downfalls of eating too much protein: “If intake of protein is more than needed, it won’t be burned and instead will be stored in the body and can lead to weight gain,” Levinson says. Also, eating too much protein might make you eat less of other important nutrients, making your diet unbalanced. If you’re replacing carbs, which your body burns for fuel, your body may start to burn protein instead (a process called ketosis), which can lead to bad breath, she adds. It can also, weirdly, make your sweat smell like ammonia—it’s one of the by-products when the amino acids in protein are broken down.
In the end, the types of protein you eat (and when) matters the most.
In general, according to the 2015 Dietary Guidelines, we’re eating enough protein. However, Levinson says, we’re not necessarily getting it from the best sources. Many people (especially boys and men) are getting too much of it from meat, poultry and eggs, and not enough from seafood and legumes, which count as both a protein and a vegetable.
Eating a variety of proteins will also ensure you’re not missing out on the other nutrients your body needs, or going overboard on calories. And it’s pretty much impossible to overeat protein on a plant-based diet, so it’s more likely you’ll naturally stay within your ideal intake range versus if you’re only getting protein from red meat and poultry.
Spacing out your protein intake throughout the day may help enhance protein’s effects on your muscles. “Research is showing that protein should be spread out throughout the day rather than the majority being consumed at one meal, which is usually what people do when they eat most of their protein at dinner,” Levinson says. She suggests getting no more than 30 grams in one meal.