Biologists could be Dieticians in UK and US

http://www.bda.uk.com/edpostgrad.html

Biologists could be members of the British Dietetic Association if they have completed accredited postgraduate courses

http://www.faseb.org/faseb/societies.html

The Federation of American Societies for Experimental Biology (FASEB). Below is the list of societies that are currently participating in the Membership Directory.-American Society for Nutrition