Protein intake recommendations for adults
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Protein Intake Recommendations for Adults: RDA, AMDR, and Health Considerations
The Recommended Dietary Allowance (RDA) for protein in adults aged 18 and older is 0.8 grams per kilogram of body weight per day. This value is designed to meet the minimum needs to avoid deficiency and maintain basic health in nearly all healthy individuals. However, the Acceptable Macronutrient Distribution Range (AMDR) suggests that protein should make up 10–35% of total daily calories, which often results in a higher intake than the RDA, especially for those with higher energy needs or specific health goals 145.
Protein Needs for Older Adults: Higher Requirements for Health and Function
Emerging evidence shows that older adults (typically over 65 years) require more protein than younger adults to maintain muscle mass, support recovery from illness, and preserve physical function. Expert groups now recommend a daily protein intake of 1.0–1.2 g/kg body weight for healthy older adults, with even higher intakes (1.2–1.5 g/kg) advised for those who are physically active or have acute or chronic illnesses. These recommendations are significantly higher than the standard RDA and are aimed at preventing age-related muscle loss (sarcopenia) and supporting overall vitality 2356910.
Protein Intake Patterns: Distribution and Quality Matter
For optimal muscle protein synthesis, especially in older adults, it is important not only to meet daily protein targets but also to distribute protein intake evenly across meals. Consuming at least 25 grams of protein per meal, three times a day, is suggested to maximize muscle health. Additionally, the quality of protein—meaning its amino acid composition and digestibility—plays a crucial role in supporting muscle and bone health. High-quality proteins, such as those from animal sources, are particularly effective 379.
Current Intake Trends: Many Older Adults Fall Short
Studies from the UK and other regions show that a large proportion of older adults do not meet even the minimum protein recommendations, with fewer than 15% reaching the 1.2 g/kg/day target. Factors such as reduced appetite, dental issues, and lifestyle habits (e.g., smoking) can contribute to low protein intake in this population. This highlights the need for clearer public health messaging and targeted interventions to help older adults achieve optimal protein intake 78.
Safety of Higher Protein Intakes
For healthy adults, long-term protein intakes up to 2 g/kg/day are considered safe, with a tolerable upper limit of 3.5 g/kg/day for well-adapted individuals. However, those with severe kidney disease (not on dialysis) may need to limit protein intake. Chronic excessive protein intake above 2 g/kg/day should generally be avoided to prevent potential health risks .
Conclusion
While the RDA for protein provides a baseline for healthy adults, growing evidence supports higher protein intakes—especially for older adults—to maintain muscle mass, strength, and overall health. Distributing protein intake across meals and focusing on high-quality sources further enhances these benefits. Many older adults currently do not meet these higher recommendations, underscoring the importance of updated guidelines and practical strategies to support healthy aging through adequate protein nutrition.
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