Hi,

According to ugc net information brochure

"Candidates are advised to appear in the subject of their Post Graduation only. The candidates, whose Post Graduation subject is not covered in the list of NET subjects attached as Annexure-IV, may appear in a related subject."

So if you found masters in nutritional science related with social medicine and community health you can apply for it in Ugc net exam.

Usually the students having masters in nutritional sciences apply for home science in ugc net.

Hops this helps.