However, the opposite is true for adults over the age of 65, researchers said. The older folks who ate moderate- or high-protein diets were less susceptible to disease.
Researchers defined high-protein dieters as those who got at least 20% of their calories from protein, whether animal- or plant-based. The people who got 10% to 19% of their calories from protein were considered moderate protein eaters, while those who ate less than 10% protein fell in the low-protein category.
The scientists found that plant-based proteins like beans and nuts did not have the same effects as animal-based proteins like meat, milk and cheese. Excess carbohydrate or fat consumption did not impact the results, according to the study.
How much protein should you be eating? Popular weight loss plans like the Paleo and Atkins diets focus on a high intake of animal proteins, but this study suggests that they could be detrimental in the long term.
Study co-author Valter Longo, director of the Longevity Institute at the University of Southern California and the founder of a company that makes plant-based “Fasting Mimicking & Enhancing” foods, said most Americans are eating double the protein they should.
“It seems that the best change would be to lower the daily intake of all proteins but especially animal-derived proteins,” Longo said in a release. “But don’t get extreme in cutting out protein; you can go from protected to malnourished very quickly.”