A major scientific review is challenging the idea that more protein is always better.
The review, led by pathologist and biomedical researcher Dudley Lamming and published in the journal Cell Press Blue, examined more than 350 studies involving humans, mice, insects, yeast and other organisms.
The review found that eating less protein, or less of certain amino acids that make up protein, may turn on body processes linked to healthier aging, as well as metabolism, the process by which the body turns food and drinks into energy.
Protein is now added to lattes, cereal, chips, ramen, and many other foods that were never traditionally marketed as protein-rich. The message seems clear: More protein must be better.
But scientists are asking if that is true for everyone. For adults who already get enough, eating more protein may offer little benefit, while some research suggests that eating less protein could support healthier aging.
Protein helps build muscle, repair tissue and help the body recover. But protein needs vary from person to person depending on age, health, body size and activity level.
The recommended daily amount for a healthy adult is 0.8 grams of protein per kilogram of body weight, or about 0.36 grams per pound.
This does not mean inactive adults should cut their daily protein intake immediately — it just means they may not need to keep adding more.
For sedentary individuals, simply moving the body may also help health more than just eating extra protein.
This review also has some limitations. The studies used different diets, protein amounts, and study lengths. Many studies were done in animals or other organisms, so the results may not fully apply to people.
Protein is still essential. But healthy adults who already get enough may not benefit from adding it to every meal, snack and drink.