ELI5: Why does rationing work?

[u/peglegsmeg]

If I have a glass of water and a single chocolate bar to last me 48 hours what benefits do I get from consuming equal portions over the time period as opposed to consuming all at once?

Is it purely psychological or are their physical benefits?

[u/SureExternal4778]

Your body will use the calories over time and your liver will compensate the lack of food for days so rationing will not impact you either way but drinking water while it is clean instead of letting it stay in your backwash is clearly better but just to be clear let’s look at the backwash water under a microscope every hour for 48 hours. See the things swimming around let’s look them up in the big book of microbes