# How long does it take to turn excess calories to fat?

**URL:** <https://boards.straightdope.com/t/how-long-does-it-take-to-turn-excess-calories-to-fat/373625>\
**Category:** Factual Questions\
**Created:** [September 21, 2006, 9:40pm UTC](https://boards.straightdope.com/t/how-long-does-it-take-to-turn-excess-calories-to-fat/373625 "2006-09-21T21:40:18Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Gr8Kat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/gr8kat/32/18668_2.png) [@Gr8Kat](https://boards.straightdope.com/u/Gr8Kat)\
**Post date:** [September 21, 2006, 9:40pm UTC](https://boards.straightdope.com/t/how-long-does-it-take-to-turn-excess-calories-to-fat/373625/1 "2006-09-21T21:40:18Z")

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How long does it take to metabolize a meal and store the excess calories as fat? If, for example, a person who’s dieting is “bad” and has a large meal of fatty foods and dessert, and then doesn’t do any additional physical activity to burn the calories, when could they realistically expect to see the weight gain on the scale? Would it be apparent by the next morning?

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**Author:** ![WhyNot](https://avatars.discourse-cdn.com/v4/letter/w/c77e96/32.png) [@WhyNot](https://boards.straightdope.com/u/WhyNot)\
**Post date:** [September 21, 2006, 9:52pm UTC](https://boards.straightdope.com/t/how-long-does-it-take-to-turn-excess-calories-to-fat/373625/2 "2006-09-21T21:52:28Z")

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I’m not sure of the exact answer, but I know things make it through the intestine and into the body’s cells, with the waste leaving the colon within [30 hours or so](http://www.vivo.colostate.edu/hbooks/pathphys/digestion/basics/transit.html), depending on what they are. It’s not a sequential thing - some bits of your breakfast may be excreted after your luch contents.

I do know from personal experience that bulimia is worthless as a weight-loss technique. Neither vomitting or purging through laxatives stops the absorbtion of calories to a noticable degree, although it sure seems like it should.