Feb 10 2012 --- EFSA has published population reference intakes (PRIs) for protein, completing the latest stage of its work on dietary reference values (DRVs).

A PRI indicates the amount of an individual nutrient that the majority of people in a population need for good health depending on their age and sex. EFSA’s Panel on Dietetic Products, Nutrition and Allergies set PRIs for protein for adults, infants and children, and pregnant and breast-feeding women, as follows:

•    Adults (including older adults) – 0.83 g per kg of body weight per day.
•    Infants, children and adolescents – between 0.83 g and 1.31 g per kg of body weight per day depending on age.
•    Pregnant women – additional intake of 1 g, 9 g and 28 g per day for the first, second and third trimesters respectively.
•    Breast-feeding women – additional intake of 19 g per day during the first 6 months of lactation and 13 g per day thereafter.

The Panel also looked at several health outcomes that may be associated with protein intake – such as bone health, body weight, muscle mass and kidney function – but concluded that the available data were insufficient to derive PRIs based on these health outcomes.

The Panel considers protein intake in the European population to be adequate for all population groups. According to collated national food consumption surveys, the average protein intake of adults in Europe is often at or above the PRI of 0.83 g per kg of body weight per day (between 67 g and 114 g per day for men and between 59 g and 102 g per day for women).

The PRIs apply to mixed dietary protein from both animal and plant sources. The Panel notes that EFSA’s Comprehensive Food Consumption Database shows that the main sources of protein in European adult diets are meat and meat products, followed by grains/grain-based products and milk/dairy products.

The Scientific Opinion on protein follows a request from the European Commission for EFSA to update previous European advice on DRVs, taking into account new scientific evidence and recent recommendations issued at national and international level. Previously the Panel has published opinions establishing DRVs for carbohydrates, dietary fibre, fats and water.

This and earlier opinions on DRVs have been adopted by the Panel after consultation with Member States, the scientific community and other stakeholders. The consultations ensure that EFSA benefits from the widest range of information, data and views to finalise the work and provide the most up-to-date, comprehensive advice to EU decision-makers.

DRVs comprise a complete set of quantitative values, including average requirements, population reference intakes, adequate intakes, reference intake ranges, lower thresholds and tolerable upper intake levels. They can be used as a basis for food labelling and for establishing food-based dietary guidelines (see also EFSA's Scientific Opinion on establishing Food-Based Dietary Guidelines).

The Panel used the nitrogen balance approach to set PRIs for protein. Nitrogen balance is the difference between nitrogen intake through food and the amount of nitrogen lost in body waste. In healthy adults the protein requirement is the amount needed to achieve zero nitrogen balance (maintenance). The factorial method is used to calculate protein requirements for physiological conditions such as growth, pregnancy or lactation. In these cases nitrogen is needed not only for maintenance but for the deposition of protein in newly formed tissue and milk. In children, nitrogen balance has to be positive to allow for growth.