From protein shakes to fortified snack bars, the push to pack more protein into every meal has become a defining wellness trend of the decade. Yet as Europe's population ages, a growing body of evidence suggests that the opposite approach—eating less protein—might be the key to a longer, healthier life.
Researchers at the University of Wisconsin-Madison analysed more than 300 studies and found that while official guidelines often recommend high-protein diets, emerging data indicate that reducing protein intake can lower the risk of age-related conditions such as diabetes and cancer. The findings, published in the journal Nature Metabolism, add to a mounting debate about how much protein we truly need.
The case for eating less protein
“It's absolutely crystal clear that there are benefits of protein to muscle growth and exercise response of active individuals,” said Dudley Lamming, the study's lead author. “But because most people are relatively sedentary, many people are likely consuming more protein than they actually need, which probably has negative health consequences.”
The review found that a low-protein diet improves metabolic function by reducing fatty tissue, increasing energy expenditure, and stabilising blood sugar levels. In both human and animal studies, participants on lower-protein diets showed better blood sugar control and less body fat, even when they consumed more total calories.
Much of this effect appears to be driven by a hormone called FGF21, which rises when protein intake is low and helps the body burn energy more efficiently. Lower protein also triggers autophagy, a cellular “repair and cleanup” process that removes damaged proteins and other cellular debris, keeping cells youthful and reducing the risk of chronic disease.
These findings resonate with broader research on healthy ageing. A global study recently warned that longer lifespans are not necessarily healthier ones, underscoring the need for interventions that improve quality of life in later years.
Not a one-size-fits-all approach
The authors stress that protein restriction is not suitable for everyone. Pregnant women, growing children, the elderly, and those recovering from major injuries need higher protein for development and repair. The study also notes that individual needs vary based on activity levels and health status.
“Recent recommendations have encouraged people to eat more protein, but they've also encouraged people to exercise more,” Lamming said. “We probably need to personalise protein recommendations based not just on age, but also on how physically active people are.”
Current guidelines from the European Food Safety Authority (EFSA) and the World Health Organization (WHO) set a population reference intake of 0.83 grams per kilogram of body weight per day. Both organisations consider up to twice that amount safe, but they note that evidence on very high protein intake remains controversial. EFSA also says there is insufficient data to set specific requirements for older adults, recommending they consume at least as much as younger adults.
The findings come as Europe grapples with rising rates of metabolic diseases and an ageing demographic. While the study does not advocate extreme protein restriction, it suggests that many people could benefit from trimming excess protein from their diets. The authors call for clinical researchers to design “suitable diets for individuals” based on personal health and lifestyle factors.
For those considering dietary changes, the study offers a nuanced message: more protein is not always better. As with many aspects of nutrition, balance and individualisation are key.
