Is there a such thing??? If I do not eat all my calories from one day (say like 100 or 200 calories) is it ok if I add them to the next day?

That would suggest that at the stroke of midnight - a bit like the Cinderella story - your body did a quick calculation and turned surplus calories eaten to fat.

I am no expert - but pretty sure that you would be fine to eat those calories the next day. Obviously you would not want to go overboard and eat nothing for a week and then a whole week's worth of calories on the last day of the week.

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