[not sure if this strictly qualifies as a lifehack, but it seems to be in the general ballpark]

I have been practising a slightly modified version of alternate-day intermittent fasting since mid-January this year. Basically, every second day, I eat a small breakfast and then nothing until midnight (or at least I try to, in practice I sometimes have a snack at 10-11 pm). There seems to be some evidence that this is good for human health, and I have found it to be rather low-cost - I am still able to do moderately strenuous physical activity on fasting days (namely cycling from university to my home, which is half an hour away and mostly uphill), and do not get particularly hungry either (although I sometimes desire certain foods, hence the snacking). All in all, this seems like the sort of thing that is worth trying.