"Wait till you are actually hungry" seems to work fine. It is extended version of @Jack's "I eat only once a day", except there is no rules. Interestingly firs

"Wait till you are actually hungry" seems to work fine. It is extended version of @Jack's "I eat only once a day", except there is no rules. Interestingly first thing they teached to American Injuns, was "warm meals thrice a day" and the result can be seen in the Indian population even today.