and to prevent deficiency symptoms. It should also maintain satisfactory stores of the nutrients in the body. Requirements are the quantities of nutrients that healthy individuals must obtain from food to meet their physiological needs. The recommended dietary allowances (RDA) are estimates of nutrients to be consumed daily to ensure the requirements of all individuals in a given population.
The recommended level depends upon the bioavailability of nutrients from a given diet. The term bioavailability indicates what is absorbed and utilized by the body. In addition, RDA includes a margin of safety, to cover variation between individuals, dietary traditions and practices Recommended Dietary Allowances = Requirement +Margin of safety The margin of safety is added to take care of factors such as . Losses during cooking and processing .
Short periods of deficient intake Unit RECOMMENDED DIETARY ALLOWANCE AND MEAL - - RECOMMENDED DIETARY ALLOWANCES AND MEAL PLANNING . Nature of the diet . Individual variations in requirements The requirement for vitamin C or ascorbic acid is actually mg/day, but since the vitamin is easily destroyed during pre-preparation, cooking and storage, the recommended intake is twice the requirement and is mg/day . .
Factors influencing RDA The RDAs apply to healthy individuals and are set high enough to cover individual variation. Recommended dietary allowances of an individual depend on many factors like . Age - Adults require more total calories than a child, whereas a growing child requires more calories per kg of body weight than an adult. .
Sex - Males with high Basal Metabolic Rate (BMR) require more calories than females. . Physical activity – The type of activity also determines the energy requirements. Based on the nature of work and level of activity different occupations are classified into three categories: • Sedentary • Moderate • Heavy Sede ntary (light work): A sedentary person is one who does most of the -work sitting at one place using only his hands and head.
A few examples of individuals undertaking sedentary work include teachers, tailors, typists, clerks, office executives, housewives who have household help. Moderate