# Starvation Question (Don't Need Answer Fast)
**URL:** https://boards.straightdope.com/t/starvation-question-dont-need-answer-fast/800925
**Category:** Factual Questions
**Created:** [November 7, 2017, 12:23am UTC](https://boards.straightdope.com/t/starvation-question-dont-need-answer-fast/800925 "2017-11-07T00:23:47Z")
**Posts on this page:** 12
**Page:** 1
### Author:  [@HeyHomie](https://boards.straightdope.com/u/HeyHomie)
#### Post date: [November 7, 2017, 12:23am UTC](https://boards.straightdope.com/t/starvation-question-dont-need-answer-fast/800925/1 "2017-11-07T00:23:47Z")
Assume an otherwise-healthy adult man, say 40 years of age, 80kg, neither obese nor possessing a remarkably low percentage of body fat, is denied food. How long until he’s so weak that he wouldn’t be able to stand? Two weeks? Three?
---
### Author:  [@Bill\_Door](https://boards.straightdope.com/u/Bill_Door)
#### Post date: [November 7, 2017, 12:27am UTC](https://boards.straightdope.com/t/starvation-question-dont-need-answer-fast/800925/2 "2017-11-07T00:27:58Z")
The survival adage is three minutes without air, three days without water, and three weeks without food.
---
### Author:  [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)
#### Post date: [November 7, 2017, 12:32am UTC](https://boards.straightdope.com/t/starvation-question-dont-need-answer-fast/800925/3 "2017-11-07T00:32:16Z")
> [@Bill\_Door](#):
>
> The survival adage is three minutes without air, three days without water, and three weeks without food.
Agree. A month under controlled conditions.
---
### Author:  [@HeyHomie](https://boards.straightdope.com/u/HeyHomie)
#### Post date: [November 7, 2017, 1:05am UTC](https://boards.straightdope.com/t/starvation-question-dont-need-answer-fast/800925/4 "2017-11-07T01:05:21Z")
That’s until he dies. I’m asking about how long until he’s conscious and breathing but too weak to move. (Need this for a story I’m writing.)
---
### Author:  [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)
#### Post date: [November 7, 2017, 1:26am UTC](https://boards.straightdope.com/t/starvation-question-dont-need-answer-fast/800925/5 "2017-11-07T01:26:44Z")
There were actually experiments done on this during World War II. See the [Minnesota Starvation Experiment](https://en.wikipedia.org/wiki/Minnesota_Starvation_Experiment).
---
### Author:  [@Xema](https://boards.straightdope.com/u/Xema)
#### Post date: [November 7, 2017, 2:48am UTC](https://boards.straightdope.com/t/starvation-question-dont-need-answer-fast/800925/6 "2017-11-07T02:48:56Z")
This (longish) article [Death by GPS](https://arstechnica.com/cars/2016/05/death-by-gps/2/) includes the story of Albert & Rita Chretien, who in 2011 got lost & stuck in their minivan in northern Nevada.
Albert walked off for help, but didn’t find it. Rita stayed with the car, where elk hunters found her alive - 49 days later. She’d had unlimited water from a nearby stream and a very small amount of candy and trail mix. She was 56 years old, and had effectively zero survival or wilderness experience or training.
The linked article doesn’t give this detail, but I believe she was (marginally) able to stand. She needed only a few days in hospital after being rescued.
---
### Author:  [@Xema](https://boards.straightdope.com/u/Xema)
#### Post date: [November 7, 2017, 2:55am UTC](https://boards.straightdope.com/t/starvation-question-dont-need-answer-fast/800925/7 "2017-11-07T02:55:14Z")
> [@Little\_Nemo](#):
>
> There were actually experiments done on this during World War II. See the [Minnesota Starvation Experiment](https://en.wikipedia.org/wiki/Minnesota_Starvation_Experiment).
This study seems not to closely match the OP’s specified conditions:
> [@Linked Wiki article](#):
>
> During the 6-month semi-starvation period, each subject’s dietary intake was cut to approximately 1,560 kilocalories per day.
---
### Author:  [@PastTense](https://boards.straightdope.com/u/PastTense)
#### Post date: [November 7, 2017, 2:59am UTC](https://boards.straightdope.com/t/starvation-question-dont-need-answer-fast/800925/8 "2017-11-07T02:59:58Z")
Read up on the 1981 Irish hunger strike where 10 prisoners starved themselves to death. Here is some preliminary information:
> **[1981 Irish hunger strike](https://en.wikipedia.org/wiki/1981_Irish_hunger_strike)**
>
> 1980s
> 1990s
> The 1981 Irish hunger strike was the culmination of a five-year protest during the Troubles by Irish republican prisoners in Northern Ireland. The protest began as the blanket protest in 1976, when the British government withdrew Special Category Status (prisoner of war rather than criminal status) for convicted paramilitary prisoners. In 1978, the dispute escalated into the dirty protest, where prisoners refused to leave their cells to wash and covered the walls of their cells ...
---
### Author:  [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)
#### Post date: [November 7, 2017, 3:39am UTC](https://boards.straightdope.com/t/starvation-question-dont-need-answer-fast/800925/9 "2017-11-07T03:39:33Z")
80kg male will probably have a 2000 calorie a day requirement assuming he is sedentary.
Each pound of fat has about 3500 calories in it. Assume the 80kg male has 10kg of fat, that is 77,000 calories. Enough for 38 days assuming all his energy comes from fat.
I think skeletal muscle only has about 400 calories per pound.
Realistically, he is going to burn a lot of skeletal muscle which will drop his metabolism. He may burn through 50+ lbs of muscle, which would drop his metabolism to closer to 1300 a day.
if I had to guess, somewhere in the 1-2 month range. A month is probably enough for him to lose 1/3 of his lean body mass and become very weak.
---
### Author:  [@Bill\_Door](https://boards.straightdope.com/u/Bill_Door)
#### Post date: [November 7, 2017, 4:55pm UTC](https://boards.straightdope.com/t/starvation-question-dont-need-answer-fast/800925/10 "2017-11-07T16:55:26Z")
> [@Wesley\_Clark](#):
>
> 80kg male will probably have a 2000 calorie a day requirement assuming he is sedentary.
>
> Each pound of fat has about 3500 calories in it. Assume the 80kg male has 10kg of fat, that is 77,000 calories. Enough for 38 days assuming all his energy comes from fat.
>
> I think skeletal muscle only has about 400 calories per pound.
>
> Realistically, he is going to burn a lot of skeletal muscle which will drop his metabolism. He may burn through 50+ lbs of muscle, which would drop his metabolism to closer to 1300 a day.
>
> if I had to guess, somewhere in the 1-2 month range. A month is probably enough for him to lose 1/3 of his lean body mass and become very weak.
He can’t last that long, nowhere near 2 months. While fat can provide calories the brain needs glucose, around 130 grams per day to survive. For people consuming a normal diet this glucose is provided by dietary carbohydrates, for people on carbohydrate restricted diets the glucose is provided by gluconeogenesis of dietary protein, and for people eating nothing this glucose is provided by by gluconeogenesis of muscle tissue. This process doesn’t differentiate between skeletal muscle which can be spared and cardiac muscle, which is kind of important.
It would be nice if during starvation the body first burned all of the fat then switched to consuming muscle but that’s not how it works.
---
### Author:  [@Wesley\_Clark](https://boards.straightdope.com/u/Wesley_Clark)
#### Post date: [November 8, 2017, 2:28am UTC](https://boards.straightdope.com/t/starvation-question-dont-need-answer-fast/800925/11 "2017-11-08T02:28:57Z")
Can’t your liver make glucose out of broken down fats? Why does it need to be proteins? I’m looking online at the biochemistry charts though and I don’t know if the body can convert acetyl COA to pyruvate. So maybe not. Either way, I thought the brain could use ketones in a low carb dieting situation.
I did find this, which implies it can happen but it isn’t efficient.
[https://www.nasw.org/users/mslong/2011/2011\_07/Gluconeogenesis.htm](https://www.nasw.org/users/mslong/2011/2011_07/Gluconeogenesis.htm)
One argument I’ve heard is that a pound of fat can only mobilize about 31 calories a day. I get the impression that isn’t set in stone, but each pound of fat can only break down and release so many calories per day. Beyond that your body starts breaking down lean tissue.
Either way, as far as OPs situation I assume at the end of the month the guy will still be alive, but he’ll be 50 pounds lighter (mostly muscle loss) and very weak.
---
### Author:  [@Bill\_Door](https://boards.straightdope.com/u/Bill_Door)
#### Post date: [November 8, 2017, 12:44pm UTC](https://boards.straightdope.com/t/starvation-question-dont-need-answer-fast/800925/12 "2017-11-08T12:44:17Z")
> [@Wesley\_Clark](#):
>
> Can’t your liver make glucose out of broken down fats? Why does it need to be proteins? I’m looking online at the biochemistry charts though and I don’t know if the body can convert acetyl COA to pyruvate. So maybe not. Either way, I thought the brain could use ketones in a low carb dieting situation. (snip)
You can use ketone bodies for energy in a low carbohydrate dieting situation for sure, but I had always been told that fat could not be metabolized to glucose as there was not a biological pathway for that to occur. That being said, I just found this [article](https://chrismasterjohnphd.com/2012/01/07/we-really-can-make-glucose-from-fatty/) on the web that says it is possible. The article is not scholarly, and certainly lacks peer review and all that, but the references given at the end look like they have a good deal more rigor.
So it looks like you can make at least a bit of supplemental glucose starting from fatty acids. I’m certainly guilty of not keeping up with the research and apologize. I’m only a regular chemist, not a biochemist, and went to college when the periodic table was only Earth, Air, Water, Fire, and Aether. It was a simpler time.