I've participated in a number of game jams, and I can only underscore the conclusion at the end of that article: a healthy body can deal with a 48h crunch period without many consequences. Staying hydrated and getting at least 8h of sleep each night helps a lot with that, and one should also avoid stimulants that one doesn't otherwise take (so if you drink a lot of coffee but few energy drinks on regular days, you should stick to coffee only during the jam) to stay healthy. Lastly, the test subjects in that study were an extreme case, since they were organizers in addition to being jammers, meaning that they have about double the workload of a regular jam participant, who has it slightly easier.
I would also like to point out that game jams have a huge psychosomatic health benefit: making your own game from scratch satisfies your intrinsic need for autonomy and competence for weeks, if not months after the jam. And if you are working with a team, or alone but at a jam site with other people, it also covers your relatedness need, leaving you feeling psychologically uplifted for a long time, with all the health benefits that brings.