Some people can’t seem to get enough protein. In shakes, in bars, in smoothies – or as big chunks of steak – it’s a macronutrient loved by many, especially in the nutrition and fitness world.
But experts disagree on the ideal amount of protein we should eat, on whether we should focus on protein to maximize our nutrition, and on whether we are in danger of eating too much protein instead.
Newsweek contacted ten different nutritionists – all with different opinions – to ask them how much protein they personally ate every day.
Many of them cited the Recommended Dietary Allowance (RDA): The U.S. National Dietary Guidelines recommend eating at least 0.8 grams of protein per kilogram (g/kg) of body weight.
For someone weighing 82kg, this means they would need to eat 65g of protein per day: just over one 10oz steak.
For nutritionist Mike Murphy – who said people should eat about 1 gram/kg per day – eating enough protein is “one of the most important nutritional goals anyone can focus on.”
He said: “Protein balances blood sugar levels, promotes satiety and it is very difficult to eat too much protein. In addition, we need proteins to repair tissues and build things in the body, such as enzymes, hormones and muscles.
“I consider muscle to be the most important organ for longevity and we cannot maintain it without getting enough protein in the diet.”
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He said he gets about 100 grams of protein a day, which might look something like this: two eggs, a slice of sourdough toast, and peanut butter for breakfast; a chicken breast, a cup of broccoli and a cup of quinoa for lunch; a handful of almonds as a snack; and a salmon fillet and half a cup of lentils for dinner.
Murphy said it is very difficult to eat too much of protein and did not warn against overeating, but others were more explicit about not worrying about overeating.
“There’s really no such thing as too much protein,” says Fredrick Hahn, a personal trainer who owns studios in New York and New Jersey. “Eating protein, which is so nutrient-dense, increases satiety and you just can’t keep eating it. Think about it: How many eggs can you really eat in one sitting?”
Melissa Boufounous, a sports nutritionist from Canada, spoke along similar lines, saying there was “a lot of fear and misconceptions” about high-protein diets.
“Many studies have shown that it is safe for healthy people to consume much more protein than the RDA,” she said, adding that the RDA was “only the minimum amount of protein needed to prevent malnutrition.” She said that serious bodybuilders, who need more protein for muscle building and tissue repair, can safely eat as much as 4.4 g/kg of protein: five times the RDI.
“Personally, I don’t see the need to eat more than 2g/kg of protein per day, but I wouldn’t worry about my health if I regularly consumed more than this amount,” said Boufounous.
Other experts were more reserved than this. For example, nutritional therapist Milena Mastroianni echoed Murphy in saying, “It is very difficult to eat too much protein, especially from animal foods,” but added that some athletes can safely eat up to 3.5 g/kg.
And she warned that focusing too much on protein sources could crowd out other beneficial foods, such as fiber-rich vegetables, healthy fats and complex carbohydrates.
Dietitian nutritionist and wellness coach Nichole Maholy also expressed a balanced view, saying that she personally wouldn’t eat more than 2.5g/kg of protein – “because it’s not necessary” – but wouldn’t be concerned about eating significantly more than to eat that.
“There are no randomized controlled trials showing that eating more protein is harmful to our health, but there is some evidence that eating more than the recommended amount can cause side effects such as digestive problems, dehydration or electrolyte imbalances, and can cause tension.” on the kidneys,” Maholy said.
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But most nutritionists Newsweek spoke said they would be concerned about eating too much protein for several reasons.
Nutritional therapist Petronella Ravenshear said excess protein was stored in the body as fat and most people did not need more than 1g/kg of protein per day.
“The accepted wisdom is that high amounts of dietary protein help us lose weight by boosting our metabolism and muscle protein synthesis, but the science doesn’t support this,” she said.
Dietitian Nichola Ludlam-Raine said that while there was “no definitive limit” on protein, there was only a limited amount of protein the body could use.
“Excessive protein intake over a long period of time can put unnecessary strain on the kidneys, especially with pre-existing kidney disease, although healthy individuals are less likely to experience problems,” she said.
Her limit was 2.2 g/kg of protein per day. In addition, “the benefits tend to level off,” she said, “and it’s important to focus on a well-rounded diet.”
Dietitian Dana Hunnes, a professor at the University of California, Los Angeles, seemed most passionately against too much protein.
“We need a lot less protein than media influencers would have you believe,” she said. “We really don’t need more protein than 1 g/kg per day. More than that can cause extra work for the kidneys.
“You want to eat just the right amount of protein, not too much and not too little. But in the US it’s very difficult to eat too little protein, especially because there’s such an emphasis on it.”
She said she stuck to plant-based proteins because they were gentler on the kidneys, packed with fiber, antioxidants, vitamins and minerals, and because they were “environmentally conscious.”
But other nutritionists, like Ravenshear and Maholy, spoke up Newsweek that they preferred to get their protein from animal foods because they contained all the amino acids (protein building blocks) the body needs and made it easier to reach their protein goals.
On the other side of the same coin was Thompson Maesaka: owner of a neurological rehabilitation clinic who trained professional sports teams, and was an amateur bodybuilder who ate 190 grams of protein per day. Even he had his limits.
“Yes, there definitely can be too much protein,” Maesaka said. “I think it’s difficult to say from person to person exactly how much is too much, and the easiest way to determine that is to use gut symptoms and overall energy as a guide.
“If I don’t balance protein sources, I become very lethargic and have a lot of stomach problems, which is my caveat to a more balanced macronutrient ratio.”
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