How much protein do we actually need?
Author of the new paper, Dr Chris Macdonald (Fellow of Lucy Cavendish College, University of Cambridge, and Director of the Better Protein Institute) says contemporary science reveals that higher levels of exercise and greater protein intake than current recommendations help people maintain physical and cognitive function as they age.
"Public health advice often focuses on the bare minimum we need to avoid problems," said Dr Macdonald. "But many people want to know what they should do to remain strong, independent, and mentally sharp throughout life."
The new paper, published in Frontiers in Nutrition , reviews evidence linking regular physical activity with lower mortality risk, improved mental health, enhanced cognition, and greater resilience against age-related decline. It highlights research suggesting that combining aerobic exercise with resistance training provides particularly strong benefits. The paper provides some useful comparisons:
“ When comparing the least active with the most active, the benefits are particularly profound. For example, low muscular strength is associated with a ~ 200% increase in all-cause mortality risk relative to high strength. Very low cardiorespiratory fitness is associated with a ~ 400% higher mortality risk compared with high cardiorespiratory fitness. In contrast, smoking is associated with a ~ 50% increase in mortality risk.”
The review also examines protein intake recommendations. Current UK guidelines are based largely on preventing deficiency in sedentary adults. According to the paper, more recent research indicates that physically active individuals, older adults, and pregnant women can benefit from substantially higher protein intakes. The paper also highlights the fat-loss benefits of higher-protein diets ( due to increased satiety and thermic effect) .
As noted in the paper, the findings call for “a cultural reframing as high-intensity exercise and high-protein diets are often associated with bodybuilders and superficial aesthetic goals. However, high-intensity exercise and high-protein diets also empower the general population to extend their lifespan and healthspan. Therefore, it is less about having “abs” and a “beach body” and more about being able to lift up, play with, and even remember, your grandchildren thanks to a strong and resilient body and mind.
When we see a stereotypical image of a hunched-over slow, fragile person with ill health, in their later years, it seems like an inevitable consequence of “Father Time”, however, I propose that in most cases, it is evidence of a non-evidence-based lifestyle. In short, we should not be quick to normalise and accept the consequences of a largely sedentary lifestyle; we should proactively empower people to reclaim their health and their independence.”
Importantly, the paper notes that higher-protein diets can be compatible with plant-based eating patterns when meals are carefully planned. Evident with the rise in competitive vegan powerlifters and bodybuilders.
What are the best sources of protein?
Published in Frontiers in Sustainable Food Systems , Dr Chris Macdonald explored what are the best sources of protein currently available.
To answer the question, Dr Macdonald had to build a new holistic scoring system that combines measures of environmental impact, health, affordability, and availability into a single framework.
Applying the scoring system to 20 commonly consumed protein-rich foods, the analysis found a striking pattern: every product in the highest-scoring quintile was plant-based, while every product in the lowest-scoring quintile was animal-based. Tofu ranked first overall, while cheddar cheese ranked last.
The paper argues that many existing food rating systems focus on only one aspect of a product. While useful, these single-dimension labels can obscure important trade-offs and make it difficult to compare foods comprehensively.
As noted in the paper, “Against deliberate corporate obfuscation and marketing myths, the goal of a holistic score is not to create a new label, but to foster a new literacy, one that empowers us to see the reality of the systems we are funding.
Ultimately, beyond the spreadsheets and scores, lies a fundamental reckoning: our protein choice is a referendum on the compassion we are willing to show to animals, to the planet, and to future generations.”
These new publications are built upon Dr Macdonald’s work at the Better Protein Institute, which also explores how to effectively shift consumer behaviour and uncovers the best investment opportunities for future sources of protein. By challenging assumptions and starting from first principles, Dr Macdonald is answering some of the most Googled questions relating to dietary protein.
Frontiers
Systematic review
People
https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2026.1853124/full
17-Jun-2026
The author(s) declared that this work was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.