# Triglycerides, their formula and bodyfat **URL:** \ **Category:** Factual Questions\ **Created:** [April 4, 2004, 2:41am UTC](https://boards.straightdope.com/t/triglycerides-their-formula-and-bodyfat/238130 "2004-04-04T02:41:37Z")\ **Posts on this page:** 12\ **Page:** 1
**Author:** ![Wesley\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wesley_clark/32/20581_2.png) [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)\ **Post date:** [April 4, 2004, 2:41am UTC](https://boards.straightdope.com/t/triglycerides-their-formula-and-bodyfat/238130/1 "2004-04-04T02:41:37Z")
Alot of people i know who are trying to lose weight say things like ‘i gained 2 lbs yesterday’, even though logically gaining 2 lbs requires eating about 7000-8000 calories more than you take in. So that got me thinking about triglycerides and i have a few questions. 1. Why does 1 pound of fat = 3500 calories in popular culture if 1lb = 454 grams and 1g fat = 9 calories? Shouldn’t it be 4086 calories per pound or does the glycerol in the triglyceride, which im assuming is counted in the weight of fat but cannot be used for energy, skew the weight of bodyfat slightly enough so that only 3500 calories can be obtained from a pound? The Glycerol seems to have the chemical formula C6H6O6, which, going by g/mol weight would make it as heavy as 7.7 H-C-H’s in a triglyceride molecule. _Assuming_ that this is the case, then woudl a normal triglyceride molecule have about 0.856% weight by H-C-H and 0.144% weight by glycerol? If so then i assume there would be about 15 H-C-H’s per chain in a triglyceride (45 total) which leads to the next question. 2. Is bodyfat stored in long chain or medium chain triglycerides? What is the chemical formula of a typical bodyfat triglyceride and how many H-C-H’s are there in one? I cannot find how many H-C-H’s there are in a typical triglyceride chain online, so for all i know it could be 10, it could be 800. ---
**Author:** ![bizzwire](https://avatars.discourse-cdn.com/v4/letter/b/958977/32.png) [@bizzwire](https://boards.straightdope.com/u/bizzwire)\ **Post date:** [April 4, 2004, 3:01am UTC](https://boards.straightdope.com/t/triglycerides-their-formula-and-bodyfat/238130/2 "2004-04-04T03:01:14Z")
My copy of Lehninger is in my office, so I can’t address your math, but I _can_ tell you that glycerol is a 3-carbon molecule with the molecular formula of C3H8O3. However, Glycerol is only one component of triglycerides, which result from the condensation of glycerol with three (“tri”-get it?) molecules of the fatty acid of your choice (the majority averaging about 16/18 carbons in length), giving a typical triglycerol a molecular weight of 854-938 daltons. ---
**Author:** ![bizzwire](https://avatars.discourse-cdn.com/v4/letter/b/958977/32.png) [@bizzwire](https://boards.straightdope.com/u/bizzwire)\ **Post date:** [April 4, 2004, 3:09am UTC](https://boards.straightdope.com/t/triglycerides-their-formula-and-bodyfat/238130/3 "2004-04-04T03:09:37Z")
Here’s Glycerol: CH2-OH | | | CH-O-H | | | CH2-O-H Here’s a triglycerol: ``` O || ``` CH2-O-C(C15H31) | | O | || CH-O-C-(C15H31) | | | CH2-O-C-(C15H31) || O ---
**Author:** ![bizzwire](https://avatars.discourse-cdn.com/v4/letter/b/958977/32.png) [@bizzwire](https://boards.straightdope.com/u/bizzwire)\ **Post date:** [April 4, 2004, 3:24am UTC](https://boards.straightdope.com/t/triglycerides-their-formula-and-bodyfat/238130/4 "2004-04-04T03:24:03Z")
wow, now _that’s_ bad coding!!! The doubly-bonded oxygens in the triacylglycerol belong on the carbon of the fatty acid. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [April 4, 2004, 4:16am UTC](https://boards.straightdope.com/t/triglycerides-their-formula-and-bodyfat/238130/5 "2004-04-04T04:16:42Z")
The simple answer to 1) from _Jane Brody’s Nutrition Book_: > [@](#): > > Each gram of fat supplies your body with 9 calories of fuel, or 245 calories per ounce of stored fat. Each pound of fatty tissue can yield 3,500 calories, somewhat less than 245 multiplied by 16, because fatty tissue contains some water and protein as well as pure fat. The amount of water also tends to vary with age, with newborns having as much as 60% water and the elderly less than 25%. The answer to 2) is much more complicated, and can’t be answered completely for any individual. True, about 95% of body fat is triglycerides, but that group has to be broken down by whether they are composed of saturated, unsaturated, or polyunsaturated fatty acids. And that appears to depend heavily on diet. According to an old textbook I kept, _Nutrition in Clinical Care_, by Howard and Bebold (1978): > [@](#): > > In animals fed on diets high in saturated fatty acids acids, the depot of animal fat was also high in saturated fatty acids. … Humans consuming a high polyunsaturated diet [have] adipose tissue that is higher in unsaturated fatty acids than are found in individuals maintained on high saturated fatty acid diet. The text doesn’t say what a breakdown of these might be for an average human. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [April 4, 2004, 4:25am UTC](https://boards.straightdope.com/t/triglycerides-their-formula-and-bodyfat/238130/6 "2004-04-04T04:25:55Z")
> [@bizzwire](#): > > My copy of Lehninger is in my office… [Charter Member Getting Snooty] Is it AUTOGRAPHED, like _my_ copy? [/Charter Member Getting Snooty] ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [April 4, 2004, 5:32am UTC](https://boards.straightdope.com/t/triglycerides-their-formula-and-bodyfat/238130/7 "2004-04-04T05:32:07Z")
[_This_ Lehninger](http://www.amazon.com/exec/obidos/tg/detail/-/1572599316/002-9533779-5268867?v=glance)? > [@](#): > > Lehninger Principles of Biochemistry, Third Edition > by David L. Nelson, David L. Nelson, Albert L. Lehninger, Michael M. Cox > > Search inside this book > List Price: $149.10 > Price: $149.10 Man, you can’t imagine how glad I am I went to college when I did. ---
**Author:** ![vasyachkin](https://avatars.discourse-cdn.com/v4/letter/v/c5a1d2/32.png) [@vasyachkin](https://boards.straightdope.com/u/vasyachkin)\ **Post date:** [April 4, 2004, 6:39am UTC](https://boards.straightdope.com/t/triglycerides-their-formula-and-bodyfat/238130/8 "2004-04-04T06:39:48Z")
did it never occur to any of you geniuses that adipose tissue might contain things like, i duno, WATER ? not just fat ? its a living tissue you know, i dont know of any living tissues that dont contain ANY water … bodybuilders dont drink water on the day of the contest to look harder/more defined. water doesnt have calories in case you dont know. ---
**Author:** ![vasyachkin](https://avatars.discourse-cdn.com/v4/letter/v/c5a1d2/32.png) [@vasyachkin](https://boards.straightdope.com/u/vasyachkin)\ **Post date:** [April 4, 2004, 6:46am UTC](https://boards.straightdope.com/t/triglycerides-their-formula-and-bodyfat/238130/9 "2004-04-04T06:46:47Z")
realistically if you gona diet you will lose a considerable amount of muscle along with fat. and muscle is mostly water … also consider things like glycogen depletion on ketogenic diets which results in water loss. all this is irrelevant anyway because the main variable is slowing down of metabolism anyway. i would not worry too much if the figure is 3000, 3500 or 4000 … ---
**Author:** ![Wesley\_Clark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wesley_clark/32/20581_2.png) [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)\ **Post date:** [April 4, 2004, 3:16pm UTC](https://boards.straightdope.com/t/triglycerides-their-formula-and-bodyfat/238130/10 "2004-04-04T15:16:52Z")
> [@vasyachkin](#): > > did it never occur to any of you geniuses that adipose tissue might contain things like, i duno, WATER ? not just fat ? > > its a living tissue you know, i dont know of any living tissues that dont contain ANY water … > > bodybuilders dont drink water on the day of the contest to look harder/more defined. > > water doesnt have calories in case you dont know. wow you’re smart. Too bad people who do things like quote scientists already replied. ---
**Author:** ![Ilsa\_Lund](https://avatars.discourse-cdn.com/v4/letter/i/a6a055/32.png) [@Ilsa\_Lund](https://boards.straightdope.com/u/Ilsa_Lund)\ **Post date:** [April 4, 2004, 3:49pm UTC](https://boards.straightdope.com/t/triglycerides-their-formula-and-bodyfat/238130/11 "2004-04-04T15:49:46Z")
> [@vasyachkin](#): > > did it never occur to any of you geniuses that adipose tissue might contain things like, i duno, WATER ? not just fat ? > > its a living tissue you know, i dont know of any living tissues that dont contain ANY water … > > bodybuilders dont drink water on the day of the contest to look harder/more defined. > > water doesnt have calories in case you dont know. Did it ever occur to you that maybe adipose tissue _didn’t_ contain very much water? I’ll refrain from the personal insults. “Roughly two thirds of the vertebrate body consists of water. The exact figure varies a great deal, particularly as a result of variations in fat content. Adipose tissue contains only some 10%, and a very fat individual, who may have half or mor of the body weight as fat, therefore has a low overall water content.” Schmidt-Nielsen, Knut. 1997. Animal Physiology: Adaptation and Environment. 5th ed: Cambridge University Press. pp.93-94 ---
**Author:** ![vasyachkin](https://avatars.discourse-cdn.com/v4/letter/v/c5a1d2/32.png) [@vasyachkin](https://boards.straightdope.com/u/vasyachkin)\ **Post date:** [April 6, 2004, 7:14am UTC](https://boards.straightdope.com/t/triglycerides-their-formula-and-bodyfat/238130/12 "2004-04-06T07:14:40Z")
> [@Ilsa\_Lund](#): > > Adipose tissue contains only some 10% _only_ 10 percent ? that is _almost exactly_ how much it takes to explain the discrepancy in the OP’s question. coincidence ? wesley clark - okay you win. i did not see the guy mentioning water and protein. when i saw all those friggin structural formulas for fats i knew the thread is headed in wrong direction.