What is the official WHO protein RDA?
For healthy adults aged 18 years and over, the World Health Organization (WHO), in conjunction with the Food and Agriculture Organization (FAO), has set the Safe Level of Protein (SLP) intake at 0.83 grams of protein per kilogram of body weight per day. This value is an updated figure from a 2002 review and is designed to meet the protein needs of 97.5% of the healthy adult population.
It is crucial to understand what this figure signifies. It represents a minimal intake level to prevent protein deficiency, not an optimal intake for maximizing health and function. For a sedentary adult weighing 70 kilograms (approximately 154 pounds), this translates to a modest 58 grams of protein per day. However, a significant body of research and many other health organizations recognize that optimal protein requirements can be much higher, particularly for specific demographics like older adults and physically active individuals.
The difference between RDA and optimal protein intake
Experts distinguish between the RDA, which is the minimum to prevent deficiency, and an optimal intake that supports long-term health benefits, such as preserving muscle mass and promoting healthy aging. The RDA was largely determined by older nitrogen balance studies, which may not accurately reflect the higher protein needs required for optimal physiological function.
Factors that influence individual protein needs
Protein needs are not one-size-fits-all. Several factors dictate an individual's optimal daily intake:
- Age: As people age, they become more resistant to the muscle-building effects of protein, a phenomenon known as 'anabolic resistance'. To counteract age-related muscle loss (sarcopenia), older adults typically require higher protein intakes of 1.0–1.2 g/kg/day or more.
- Physical Activity Level: Exercising individuals, including athletes, have increased protein requirements to repair exercise-induced muscle damage and support muscle growth. Recommendations range from 1.2–1.6 g/kg/day for endurance athletes and up to 1.6–2.2 g/kg/day for strength/power athletes.
- Pregnancy and Lactation: Due to the demands of fetal development and milk production, pregnant and lactating women need significantly more protein than the average adult.
- Health Status: Individuals recovering from illness, injury, or surgery have elevated protein needs to support tissue repair and immune function. Conversely, those with severe kidney disease may need to limit their protein intake and should consult a doctor.
- Body Composition Goals: People seeking to lose weight may benefit from a higher protein intake, which promotes satiety and helps preserve lean muscle mass during a calorie deficit.
Animal vs. plant protein quality
Not all protein sources are equal. The 'quality' of a protein depends on its amino acid profile and digestibility. This difference is especially relevant when meeting high protein demands.
Protein source comparison
| Feature | Animal Protein | Plant Protein |
|---|---|---|
| Completeness | Considered 'complete' proteins, containing all nine essential amino acids. | Often 'incomplete,' meaning they lack sufficient amounts of one or more essential amino acids. Can be made complete by combining different plant sources. |
| Bioavailability | Generally higher and more easily absorbed by the body. | Tends to be lower due to the presence of fiber and other compounds that can inhibit absorption. |
| Essential Amino Acids | Rich source of essential amino acids, including leucine, which is critical for muscle protein synthesis. | Some plant sources, like soy and quinoa, are complete proteins, but many others require careful combining to ensure adequate essential amino acid intake. |
| Other Nutrients | Can come with saturated fats and cholesterol, but also provide key nutrients like iron and vitamin B12. | Generally higher in fiber and offer a wider range of phytochemicals, potentially lowering the risk of certain chronic diseases. |
How to meet your protein RDA and optimal needs
Achieving your protein goals, whether the WHO RDA or a higher optimal intake, can be easily done with a balanced diet. It is also beneficial to distribute your protein intake throughout the day to optimize muscle protein synthesis.
Here are some examples of high-protein foods to include in your diet:
Animal-based sources
- Lean Meats: Chicken breast, turkey, and lean cuts of beef or pork are excellent sources of high-quality, complete protein.
- Fish and Seafood: Fish like salmon, tuna, and sardines not only offer protein but also healthy omega-3 fatty acids.
- Eggs: A highly bioavailable and complete source of protein, easily incorporated into any meal.
- Dairy: Greek yogurt, milk, and cottage cheese are rich in protein and calcium. Spreading intake across meals helps with muscle synthesis.
Plant-based sources
- Legumes: Lentils, beans, and chickpeas are versatile and packed with protein and fiber.
- Soy Products: Tofu, tempeh, and edamame are complete plant-based protein sources.
- Nuts and Seeds: Almonds, walnuts, chia seeds, and pumpkin seeds offer a great protein boost and healthy fats.
- Whole Grains: Quinoa is a complete protein, while grains like oatmeal can contribute to your daily total.
Conclusion
The WHO protein RDA of 0.83 g/kg/day serves as a critical baseline to prevent deficiency in healthy adults. However, a deeper understanding of dietary protein reveals that optimal intake varies significantly based on individual factors such as age, activity level, and health goals. For older adults, athletes, and those recovering from illness, a higher protein intake is often recommended to maintain muscle mass, support recovery, and maximize overall health and function. By focusing on a balanced diet incorporating a variety of high-quality protein sources, individuals can easily meet their specific needs. It's advisable for those with specific health conditions or high activity levels to consult a healthcare professional to determine the most appropriate intake for their situation, moving from a mindset of preventing deficiency to one of promoting optimal wellness. For a comprehensive overview of global dietary protein trends and recommendations, see this article by Arla Foods Ingredients.(https://www.arlafoodsingredients.com/the-whey-and-protein-blog/research/protein-requirements-where-are-we-now-and-where-do-we-go-from-here/)
