# I eat 2,000 Calories; Am I Necessarily Absorbing All of Them\> **URL:** \ **Category:** Factual Questions\ **Created:** [June 2, 2008, 11:44am UTC](https://boards.straightdope.com/t/i-eat-2-000-calories-am-i-necessarily-absorbing-all-of-them/451455 "2008-06-02T11:44:17Z")\ **Posts on this page:** 9\ **Page:** 2
**Author:** ![bouv](https://avatars.discourse-cdn.com/v4/letter/b/bc8723/32.png) [@bouv](https://boards.straightdope.com/u/bouv)\ **Post date:** [June 3, 2008, 1:49am UTC](https://boards.straightdope.com/t/i-eat-2-000-calories-am-i-necessarily-absorbing-all-of-them/451455/21 "2008-06-03T01:49:58Z")
[QUOTE=John Mace] Depends on the food. To get even more gross than **Sam Stone** , ever notice some identifiable bits in your poop? You didn’t get any of those calories. 🙂 [/QUOTE] There’s no calories in them to get. Or at least, none that our digestive systems can get. We aren’t “equipped” to digest certain parts of plants, like cellulose. A cow, on the other hand, can, thanks to it’s multi-chambered stomach and chewing it’s own cud. ---
**Author:** ![panache45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/panache45/32/64_2.png) [@panache45](https://boards.straightdope.com/u/panache45)\ **Post date:** [June 3, 2008, 5:27am UTC](https://boards.straightdope.com/t/i-eat-2-000-calories-am-i-necessarily-absorbing-all-of-them/451455/22 "2008-06-03T05:27:10Z")
[QUOTE=Usram] Well, by _E=mc[sup]2[/sup]_ a 100g turd would have 2,151,051,624,000 calories according to my calculations. [/QUOTE] Only if it is propelled from your body at the speed of light. :eek: ---
**Author:** ![picker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/picker/32/13969_2.png) [@picker](https://boards.straightdope.com/u/picker)\ **Post date:** [June 3, 2008, 5:48am UTC](https://boards.straightdope.com/t/i-eat-2-000-calories-am-i-necessarily-absorbing-all-of-them/451455/23 "2008-06-03T05:48:46Z")
[QUOTE=Fear Itself] Burning turds does not convert matter into energy. [/QUOTE] Obviously you’re not doing it right. ---
**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\ **Post date:** [June 3, 2008, 1:17pm UTC](https://boards.straightdope.com/t/i-eat-2-000-calories-am-i-necessarily-absorbing-all-of-them/451455/24 "2008-06-03T13:17:29Z")
[QUOTE=picker] Obviously you’re not doing it right. [/QUOTE] Probably because my cyclotron is in the shop for repairs. ---
**Author:** ![Quercus](https://avatars.discourse-cdn.com/v4/letter/q/7ab992/32.png) [@Quercus](https://boards.straightdope.com/u/Quercus)\ **Post date:** [June 3, 2008, 1:27pm UTC](https://boards.straightdope.com/t/i-eat-2-000-calories-am-i-necessarily-absorbing-all-of-them/451455/25 "2008-06-03T13:27:57Z")
[QUOTE=Fear Itself] Burning turds does not convert matter into energy. [/QUOTE] It’s probably accurate to say that it does, but only a tiny bit of the matter. ---
**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\ **Post date:** [June 3, 2008, 1:34pm UTC](https://boards.straightdope.com/t/i-eat-2-000-calories-am-i-necessarily-absorbing-all-of-them/451455/26 "2008-06-03T13:34:15Z")
[QUOTE=Quercus] It’s probably accurate to say that it does, but only a tiny bit of the matter. [/QUOTE] No, not even a tiny bit of mass is converted to energy. Combustion is a chemical reaction that converts one compound into another (ie, solids into gas and ash), liberating heat in the process. But the mass of the resulting gases and ash is equal to the mass of the original solid. ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [June 3, 2008, 6:51pm UTC](https://boards.straightdope.com/t/i-eat-2-000-calories-am-i-necessarily-absorbing-all-of-them/451455/27 "2008-06-03T18:51:02Z")
[Sayeth Wiki](http://en.wikipedia.org/wiki/Mass%E2%80%93energy_equivalence#Practical_examples): > [@](#): > > Whenever energy is added to a system, the system gains mass. A spring’s mass increases whenever it is put into compression or tension. Its added mass arises from the added potential energy stored within it, which is bound in the stretched chemical (electron) bonds linking the atoms within the spring. Raising the temperature of an object (increasing its heat energy) increases its mass. If the temperature of the platinum/iridium “international prototype” of the kilogram—the world’s primary mass standard—is allowed to change by 1°C, its mass will change by 1.5 picograms (1 pg = 1 × 10–12 g). > Note that no net mass or energy is really created or lost in any of these scenarios. Mass/energy simply moves from one place to another. These are some examples of the transfer of energy and mass in accordance with the principle of mass–energy conservation. > > Note further that in accordance with Einstein’s Strong Equivalence Principle (SEP), all forms of mass and energy produce a gravitational field in the same way. So all radiated and transmitted energy retains its mass. ---
**Author:** ![NajaNivea](https://avatars.discourse-cdn.com/v4/letter/n/22d042/32.png) [@NajaNivea](https://boards.straightdope.com/u/NajaNivea)\ **Post date:** [June 3, 2008, 6:56pm UTC](https://boards.straightdope.com/t/i-eat-2-000-calories-am-i-necessarily-absorbing-all-of-them/451455/28 "2008-06-03T18:56:25Z")
[QUOTE=bikebloke] I wonder why some moon-bat hasn’t come up with a diet based on this? “Eat chalk and watch the fat melt away…” [/QUOTE] Or “chow down on a fistful of Tums before every meal!” Both calcium carbonate and citrate are pretty close to as digestible as the calcium in milk, so assuming you’re taking in magnesium with it, I wonder…? ---
**Author:** ![Philster](https://avatars.discourse-cdn.com/v4/letter/p/13edae/32.png) [@Philster](https://boards.straightdope.com/u/Philster)\ **Post date:** [June 3, 2008, 8:35pm UTC](https://boards.straightdope.com/t/i-eat-2-000-calories-am-i-necessarily-absorbing-all-of-them/451455/29 "2008-06-03T20:35:22Z")
Answers: [http://irweb.swmed.edu/chn/naa/tipsheets/ca\_wtloss.htm](http://irweb.swmed.edu/chn/naa/tipsheets/ca_wtloss.htm) Calcium supplements help, but getting from dairy products more effective. google ‘calcium weight loss’ for references to various studies. [Previous page](https://boards.straightdope.com/t/i-eat-2-000-calories-am-i-necessarily-absorbing-all-of-them/451455.md?page=1)