The Old Protein Playbook
For decades, the standard nutritional advice for protein has been guided by the Recommended Dietary Allowance (RDA), which suggests 0.8 grams of protein per kilogram of body weight for most healthy adults. This number was established based on studies
designed to find the minimum amount needed to prevent a deficiency, not the optimal amount for thriving. For a 70-kilogram person, this translates to about 56 grams of protein per day. This one-size-fits-all figure has been the foundation of dietary guidelines for years, but recent scientific reviews are challenging whether this baseline is sufficient, especially for two key groups: older adults and those who are physically active.
A Shift in Scientific Thinking
The conversation is shifting from merely preventing deficiency to promoting optimal health and function. A recent wave of research, including comprehensive reviews of hundreds of studies, highlights that our protein needs are not static. They change with age and physical exertion. A key reason for this is a phenomenon known as "anabolic resistance," which becomes more pronounced as we get older. This means that the body's muscle-building machinery becomes less responsive to the same amount of protein. As a result, a dose of protein that would have easily stimulated muscle repair in a 30-year-old may be insufficient for a 70-year-old.
Higher Needs for Healthy Aging
As we age, we naturally lose muscle mass and strength, a condition known as sarcopenia. This age-related muscle loss is a major factor in frailty, reduced mobility, and an increased risk of falls. To combat this, multiple expert groups and studies now recommend a higher protein intake for adults over 65, suggesting a range of 1.0 to 1.2 grams of protein per kilogram of body weight. For a 70-kilogram older adult, this would be 70 to 84 grams daily, a significant increase from the standard RDA. Some recommendations go even higher, up to 1.6 g/kg, especially when paired with resistance training, to effectively preserve muscle mass and function. The timing matters, too; spreading this protein intake evenly across meals can help maximize the body's ability to use it for muscle maintenance.
Fueling an Active Lifestyle
It is widely accepted in sports nutrition that individuals who exercise regularly require more protein than sedentary people. Exercise, whether it's endurance training or lifting weights, creates a demand for amino acids to repair and rebuild muscle tissue. The International Society of Sports Nutrition and other bodies suggest that active individuals and athletes consume between 1.4 to 2.0 grams of protein per kilogram of body weight daily. For a 70-kilogram person, that's 98 to 140 grams of protein. Endurance athletes generally fall into a range of 1.2 to 1.4 g/kg, while those focused on strength and power may need the higher end of the spectrum to optimize recovery and adaptation to training.
It’s Not Just How Much, But When and What Kind
Beyond the total daily amount, emerging research also emphasizes the importance of protein distribution and quality. To overcome anabolic resistance, older adults may need a larger dose of protein per meal—around 30 to 40 grams—to effectively trigger muscle protein synthesis. Simply meeting a higher daily total with small, scattered amounts may not be as effective. The type of protein also plays a role. Sources rich in the essential amino acid leucine—such as whey, meat, fish, and eggs—are particularly effective at signaling muscle growth. However, a well-planned diet including varied plant-based sources like soy, lentils, and nuts can also meet protein needs effectively.
