Obesogenic means likely to make people fat — usually of an environment, a diet, a city layout, or a way of life, not of a single snack. An obesogenic environment is one where cheap high-calorie food is easy to get and moving your body is hard (long car trips, few safe pavements, huge portions). It is a specialist word: you meet it in public-health papers, serious news, and university writing, not in chat. It does not mean “already obese”; it means “tending to produce obesity.”