Why is there such a difference in the proportion of the population whose needs are met by the RDA versus the EER?

The Recommended Dietary Allowance (RDA) is set to meet the nutritional needs of the majority of the population, typically covering about 97-98% of individuals, while the Estimated Energy Requirement (EER) reflects the average energy intake needed for maintaining energy balance in a healthy population. The RDA is based on specific nutrient requirements, which can be more precisely defined, whereas the EER accounts for various factors like age, sex, weight, and activity level, leading to a broader range of energy needs. Consequently, fewer individuals may meet their energy needs precisely at the EER compared to the more targeted approach of the RDA for specific nutrients.