Hi all!

Im a medical student from Denmark. I have visited these forum before and learnt a lot, but this is my first time writing. Im about to do a kind of literature review in school and Im really a beginner at that, so; since I know a lot of you guys are awesome, I would really appreciate some help regarding a matter I was wondering about. I need to know what kind of study this (type of) is:

A study where people with type 2 diabetes go through gastric bypass and where certain metabolic parameters (GLP-1) are being measure before and after the surgery (to see if/how GLP-1 changes after surgery).

How would you classify this study? Its clearly not an RCT or a review. I really suck at this, but would you call it an "observational cohort study" perhaps? But theres no control group or anything, maybe something completely different?

Thanks in advance, cheers!