To cite items from Obesity Abstracts, please make sure you include the names of the authors, year of publication, abstract title and, most importantly, the fact that it is from Obesity Abstracts, with volume and abstract number. You may also wish to include the name of the conference.
For example:
Nother A 2019 The role of weight loss in managing type II diabetes. Presented at Society for Endocrinology Obesity Update 2019, London, UK. Obesity Abstracts 1 S9