Publisher's Website:
AMA manual of style: a guide for authors and editors, 11th edition
One exception to AMA style for JAND is that "reference citations in the Journal must list all authors’ names; use of “et al” is not acceptable."
Use ZoteroBib to quickly generate bibliography entries in almost any style. Search for your items by title, DOI, etc., then search for "Academy of Nutrition and Dietetics" to add the style to the available options.
If you find this handy, consider using the Zotero citation manager to gather and organize sources as you do your research, and to create citations and bibliographies as you write.