I think it’s generally optimal to do a daily fast, as the daily food intake entrains circadian rhythms which is beneficial. You can make the fast more stringent by making the daily fast longer, eg 18 hours or 20 hours instead of 16 hours. I do longer fasts once a year during Lent/Triduum for religious reasons more than health, although there might be health benefits to a once-a-year long fast.