The Old Rulebook and Its Limits
For years, the standard advice for protein was straightforward: about 0.8 grams of protein per kilogram of body weight. This one-size-fits-all number was designed to prevent deficiency in the average sedentary adult. However, a growing body of scientific
evidence suggests this baseline is just that—a starting point, not the optimal amount for everyone. Recent reviews and even new federal dietary guidelines in some countries are now recommending higher intakes, reflecting evidence that more protein can better support muscle mass, metabolic health, and functional strength. The consensus is shifting from simply avoiding deficiency to actively optimising health, and that requires a more nuanced conversation.
Age: A Key Factor in Protein Needs
As we get older, our bodies become less efficient at using the protein we eat, a phenomenon sometimes called "anabolic resistance." This means older adults need more protein just to get the same muscle-building and maintenance benefits as their younger counterparts. To preserve muscle mass, prevent frailty, and support overall health, many experts now recommend that adults over 65 aim for 1.0 to 1.2 grams of protein per kilogram of body weight, and even more if they are managing chronic or acute illnesses. This is a significant increase from the old 0.8 g/kg target and underscores why a single recommendation for all adults can be misleading.
Activity Level: The Athlete’s Equation
It’s no surprise that what you do all day changes what you need to eat. For those who are physically active, protein is not just a nutrient; it's essential for repair, recovery, and adaptation. Sedentary individuals might be fine near the baseline, but once you start exercising regularly, your needs increase. Endurance athletes like runners and cyclists are often advised to consume between 1.2 to 1.7 grams per kilogram of body weight to support recovery. Strength training individuals looking to build muscle may need similar amounts, in the range of 1.4 to 1.7 g/kg. This increased intake helps repair the muscle damage that occurs during exercise and provides the building blocks for stronger, more resilient muscles.
Health Goals: Weight Management vs. Muscle Gain
Your personal health goals also play a major role in determining your ideal protein intake. If you're trying to lose weight, a higher protein diet can be a powerful tool. Protein is highly satiating, meaning it helps you feel fuller for longer, which can naturally lead to consuming fewer calories. Research suggests an intake of 1.2 to 1.5 g/kg can support fat loss while helping to preserve precious muscle mass, which is often lost during calorie restriction. On the other hand, if your primary goal is to build muscle, your focus will be on providing your body with sufficient building blocks, which means aiming for the higher end of the activity-based recommendations and ensuring you are in a slight calorie surplus.
Timing and Quality: It’s Not Just About the Total
The latest thinking on protein also considers when and how you consume it. Rather than eating the bulk of your protein in one large dinner, research suggests it is more effective to distribute your intake evenly across your meals. Aiming for about 25-30 grams of protein at breakfast, lunch, and dinner can help maximise muscle protein synthesis throughout the day, especially for older adults. The quality of the protein also matters. While the debate between plant and animal protein continues, the key is to ensure you’re getting a full range of essential amino acids, the building blocks of protein that your body cannot produce on its own.
