Recommended Average Daily Protein Intake
For healthy adults with minimal physical activity, consume at least 1.0-1.2 g/kg body weight per day of protein, which exceeds the minimum RDA of 0.8 g/kg/day and provides optimal health benefits beyond just preventing deficiency. 1
Standard Baseline Requirements
The minimum protein requirement to avoid progressive loss of lean body mass is 0.8 g/kg/day, which translates to approximately 56 g daily for a 70 kg man and 46 g for a 57.5 kg woman. 1 However, this RDA represents only the floor—the amount needed to prevent deficiency—not the amount for optimal health outcomes. 1
Optimal Intake for General Adults
The International Society of Sports Nutrition recommends 1.0-1.2 g/kg/day for most adults to achieve health benefits beyond minimum requirements. 1 This higher intake supports:
- Better appetite regulation and weight management 2
- Prevention of age-related muscle loss (sarcopenia) 2
- Maintenance of metabolic health 2
Current evidence indicates that intakes of at least 1.2-1.6 g/kg/day of high-quality protein represent a more ideal target for optimal health outcomes in adults. 2
Activity-Based Adjustments
Protein needs scale with physical activity level:
- Minimal physical activity: 1.0 g/kg/day 1
- Moderate physical activity: 1.3 g/kg/day 3
- Intense physical activity/athletes: 1.6 g/kg/day or higher 1
- Resistance-trained athletes building muscle: 1.4-2.0 g/kg/day 4
- Athletes during caloric restriction: 2.3-3.1 g/kg/day may maximize lean mass retention 4
Special Population Considerations
Older Adults (≥65 years)
Consume at least 1.0-1.2 g/kg/day, with higher amounts (1.2-1.5 g/kg/day) recommended for those with acute or chronic illness. 1 The European Society for Clinical Nutrition and Metabolism emphasizes this higher intake helps prevent sarcopenia and maintain functional independence. 1
During Weight Loss
Individuals with diabetes or those on energy-restricted diets may require more than the standard RDA (potentially up to 1.0 g/kg/day or 100 g/day) due to altered protein metabolism and increased protein turnover. 5
Safety Upper Limits
Long-term consumption of 2 g/kg/day is safe for healthy adults, with a tolerable upper limit of 3.5 g/kg/day for well-adapted individuals. 3 However, chronic intake exceeding 2 g/kg/day may result in digestive, renal, and vascular abnormalities and should be avoided in most populations. 3
Protein Quality and Distribution
Both animal and plant proteins can meet protein needs when consumed in adequate amounts. 1, 6 For optimal muscle protein synthesis, distribute protein evenly across 3-4 meals throughout the day, with each meal containing 0.25 g/kg body weight or 20-40 g of high-quality protein. 4
Common Pitfalls to Avoid
- Don't rely solely on the 0.8 g/kg/day RDA: This represents minimum needs, not optimal intake for health and function. 1
- Avoid protein intake >20% of total daily calories if you have kidney concerns: Seven studies showed that protein intake rarely exceeded 20% in patients with and without nephropathy, and those consuming ≥20% had higher albumin excretion rates. 5
- Don't ignore total energy intake: Protein requirements must be considered in context of overall caloric intake, especially during energy restriction. 5
- Recognize that self-reported protein intake may underestimate needs by 10-20% compared to objective measures. 1, 6