I also got that vibe in a paragraph preceding the paper that has a Clickbank affiliate link to a book on the subject of intermittent fasting. The author goes on

I also got that vibe in a paragraph preceding the paper that has a Clickbank affiliate link to a book on the subject of intermittent fasting. The author goes on to state "...it has helped many people get leaner and healthier with a relaxed mindset." That kind of hinted to me where the bias of the paper would be. However, such bias could've resulted from the information he found during his studies.