Consume Product

Practical question with regard to possible future food shortages, for people in survival situations like soldiers, but I was also curious if it was a way of identifying an optimal way for people to lose weight
 
Anyone know what is recommended? And if and how this might differ from people simply aiming to lose weight? (Because there are frequent disagreements about how people ought to lose weight, and still an "obesity pandemic" continuing, but I thought this was an angle I hadn't thought of this problem from)
 
I don't recall if the film or book of "The Road" had content I would caution against, but they were in a post-apocalyptic situation where they had a low food supply so I remember wondering what their strategy should be in such a scenario (eat a lot on a day, then skip days to eat? Eat every day? etc.)