PROTEIN

Unlike the other food energies the Panel on DRVs felt that there was enough information on which to set RNIs and EARs for protein . The average contribution of 15 percent of food energy to be supplied by protein is in actual fact the population average and above the RNI. There has been concern that excessive intakes of protein may be associated with health risks. There is some evidence that excessive dietary protein may contribute to demineralisation of bone, although the relationship is not a simple one and increases in dietary phosphorus, which usually accompany increased dietary protein, may minimise any such effect. Populations consuming vegetarian diets, which on average contain less protein, may exhibit lower blood pressure and there is firm evidence that excessive dietary protein contributes to deterioration of renal function in patients with renal disease i.e. kidney. Whilst there is at present relatively little firm evidence in this area and insufficient information to enable a safe upper limit to be defined, the Panel on Dietary Reference Values concluded that it was prudent for adults to avoid protein intakes of more than twice the RNI. The RNI for protein for adults is 0.75 grams (g) per kilogram (kg) body weight. The excess intake is therefore calculated from 1.5 g per kg body weight. For the population in general, this upper limit does not imply any change in dietary habits. However, for some groups involved in very intense physical activity at the workplace or during recreational activities, protein intakes could well be in excess of this. This can best be seen by looking up the Dietary Reference Values for a male, 19 to 29, any sensible weight and the highest physical activity levels. The average contribution to food energy (AVG) for protein is in actual fact higher than the excess amount. This is correct, although it may not seem so. The contribution towards total energy from protein of 15% is an allowance based on the actual population average intake. 15% of the EAR for Calories for these groups of people is greater than 1.5g per kg body weight. Try to keep your actual intake of protein between the RNI and Excess, and obtaining extra energy requirements from carbohydrate. There is currently insufficient evidence for any benefit from high protein intakes in these groups. However, when considering the safety of such intakes it should be assumed that the potentially adverse influences discussed above will also apply. Vegetarians - For diets which contain considerable amounts of unrefined cereal grains and vegetables, a correction for digestibility of 85% should be applied to the RNI and for those based on refined cereals the correction should be 95%. However, if protein accounts for 15% of food energy, then these corrections will already be covered, since, as stated earlier, the RNI for protein is less than 15% of food energy.