cent of children 4 through 8 years of age are estimated to have usual intake less than the requirement.

Mean or median intakes of nutrients with EARs seldom, if ever, can be used to assess adequacy or excessive intake of group diets. The prevalence of inadequacy depends on the shape and variation of the usual intake distribution, not on mean intake. For food energy, however, mean intake relative to the EAR is a possible measure to use in assessing the adequacy of group diets. Because there is a high correlation between energy intake and energy expenditure (requirement), median intake of food energy should be close to the requirement for there to be low risk of inadequate or excessive intake.

Caution also is necessary when interpreting descriptive statistics for nutrients with an AI. When mean usual intake of a group exceeds the AI the expected prevalence of inadequate intake is low. When mean usual nutrient intake of a group is less than the AI, however, nothing can be inferred about the probability of inadequacy (see Chapter 5).

In short, comparing mean intake either to the EAR or RDA or simply looking at mean intake levels should not be used to assess or imply relative nutrient adequacy.

Research studies often focus either on differences in nutrient intake for population subgroups or on the relationship between certain factors and nutrient intakes. Such studies are simply extensions of the dietary survey applications discussed above. They typically use both descriptive and multiple regression analyses to examine