Considerations in Support of Uses of the AMDR

As part of its evidence-gathering activities, in February 2024, the committee held a virtual workshop, Rethinking the AMDR for the 21st Century. The committee also conducted a narrative literature review (as described below). Box 4-1 shows a list of reported uses of the AMDR presented by speakers in the workshop and from the committee’s review of the literature.

BOX 4-1

Summary of Applications of the Acceptable Macronutrient Distribution Range (AMDR).

The workshop included speakers from a variety of different organizations that plan and/or assess diets of individuals and/or groups (see Appendix B).¹ Most, but not all, presenters reported using the AMDR. For each institution represented, the committee obtained information on the applications of the AMDRs with examples of specific applications within the stakeholder’s domain and the extent of their reliance on the AMDR to achieve their work. Specific applications included employing the AMDR as a qualitative check or as an assessment or planning tool. Some speakers reported that they were mandated to use the Dietary Reference Intakes (DRIs), but none had a legislative or regulatory requirement to use the AMDR specifically.

Overall, the AMDRs were reported as being used as a primary or secondary tool for assessment of diets or for dietary planning. For some users, the AMDR provided a check for overall dietary quality after using other DRI values to evaluate adequacy, safe upper levels of intake, and/or chronic disease risk reduction. A clear message conveyed in the workshop was the lack of consistency in either the way users applied the AMDRs or in their dependency on it.

Some users reported using the AMDR for public health applications because it enhanced flexibility in menu development. These users indicated that they would find it difficult to carry out their work if the AMDR was not retained. To illustrate, in an institution operating under national authority, the AMDRs were used in menu planning for groups of persons at multiple sites across the country. In such cases, the AMDR was used to develop a national 28-day cycle menu to help ensure that nutritional requirements were met for a broad range of individuals. This offered a rationale for keeping the AMDRs because they served as the foundation for dietary planning in a publicly funded setting. However, it became apparent from the presentations that there was variation in application of the AMDR and awareness of the strength of the evidence.

Other users reported that the AMDR was used for menu planning only and not as a primary assessment tool. In clinical practice, the AMDRs were reported as being used in planning diets for populations with metabolic disorders, which was not the original intent, as the DRIs are not therapeutic values. Some users noted that for dietary guidance, the AMDRs could be used as benchmarks (e.g., for a representative or single diet with the aim of having mean macronutrient levels fall within the AMDR boundaries). Conversely, for a distribution of simulated diets, the aim was to have an acceptable proportion of diets with macronutrient content within the AMDR boundaries. Issues related to macronutrient quality were noted.

To identify additional evidence supporting the reported uses of the AMDR, the committee carried out a non-systematic narrative literature search in Embase and Medline using the search terms “AMDR” and “Acceptable Macronutrient Distribution Range.” The search included articles published through April 2024. Results of the literature search are presented in Table 4-2 and Appendix C. Although many of the users in the workshop reported using the AMDR as an assessment tool, a variety of other applications were found in the published literature. For example, the AMDR is used in dietary planning for clinical trials. Interestingly, the literature search revealed that researchers from many countries globally applied the AMDR to assess dietary intake in the local populations. Numerous articles reported applying the AMDR to assess populations with risk factors for chronic disease. Additionally, some applied the AMDR in weight loss regimens or for sports medicine, muscle, or endurance studies.

Two studies pointed out that the Recommended Dietary Allowance (RDA) for protein intake, based on grams per kilogram (kg) body weight per day, differed from that calculated from the protein AMDR range (10–35 percent of calories). The authors noted that the lowest level of protein intake suggested in the AMDR (10 percent of calories) was higher than would be achieved by consuming protein at the RDA level (0.8 grams per kg) (Wolfe, 2015; Wolfe et al., 2017). It was further noted that using the AMDR rather than the RDA for planning and assessing dietary patterns provided more flexibility in the amount of protein that could be consumed in the context of a complete diet, especially under differing physiologic conditions.