Fat person vs Thin person during famine...who lives longer?

While I was eating today, this crossed my mind:

If a fat person and a thin person were to both stop eating or be deprived of food
(but could drink water), who would last longer?

My assumption is that a fat person would be able to survive longer without food because they have more “stored calories” to burn off / metabolize to stay alive longer while the thin person would become so emaciated they would die earlier.

Now the reason why I said drinking water was allowed is because no matter if you are fat or thin, young or old, anyone who is deprived of water cannot live for longer than 3 days (or so) and it’s generally equal across the board.

You are correct. It is why animals have evolve to have fat deposits in the first place.

My 80-something year old aunt (who was a nurse back in the day, if that makes a difference) is a few pounds heavier than she should ‘technically’ be. Once in a while a doctor will mention it to her. Ignoring that at 80+ years old, she’s not going to change her habits, she always mentions that she prefers to be a bit on the heavy side so so if she gets sick, specifically with something that causes weight loss, it buys her some time before she’s dangerously underweight/under nourished.

Of course, to be fair, it’s also an excuse to eat chocolate mouse right out of the container.

I think there should be 3 categories in play here, (too) thin, healthy and fat.

A middle aged 5’ 10" (non athlete) male at 120 is probably too thin and will not do well under famine conditions.

The same person at 220 pounds (non athlete) is over weight and because of this, is likely to have underlying health problems such as heart and/or kidney conditions, etc. and the strain on their body during a famine will probably finish them off.

The same person at 160 pounds will probably be in relatively good health will probably do best simply because they are beginning the famine in much better physical condition than the other two.

Angus Barbieri of Scotland went 382 days without eating solid food, lost 276 pounds (from 456 lb to 180 lb), and went on to live another 23 years.

In the early 1980s, several IRA prisoners went on hunger strike, but did take water. They were mostly of normal, healthy weight before the strike. Ten of them died. I don’t know how long they all lived, but somewhere around 60 days seems about average. Bobby Sands lived 66 days before dying, Francis Hughes lived 59 days, and Thomas McElwee lived 52 days.

So Barbiere lasted 4 to 6 times longer than the hunger strikers, and still survived. It’s not quite conclusive because Barbieri took electrolytes, vitamins, and occasionally a little milk, none of which applies to the hunger strikers. Nevertheless, I think it’s pretty clear gordo beats flaca in this contest.

By and large, yes, the person with more fat will live longer.

Somewhat surprisingly given what’s asserted online, this is not actually the case. Depending on the situation (i.e. not out in a hot arid desert, and if no physical exertion), people can live for 10 to 14 days without water. Not only I have seen this multiple times, it’s the figure we tell patients (but more usually their families) that’s possible in palliative situations when IV fluids are to be stopped in someone not taking anything by mouth.

I don’t think that 220 pounds is sufficiently overweight so that heart or kidney problems would be necessarily indicated, especially in a younger person, at least to the extent that they would be fatal.

Beyond the caloric value of the additional fat, metabolic differences also would affect the length of survival. Although larger individuals burn more calories in absolute amounts, those with a larger percentage of body fat compared to muscle mass burn less. (And women burn fewer calories than men at the same weight, in part due to a lower percentage of muscle compared to fat.) And as you lose weight your metabolism slows, so you gradually lose less weight per time.

In any case, given a thin person vs a fat person who have the same muscle mass, but the fat person has a large percentage of fat (which is not very metabolically active), I don’t think there’s any question that the person who started off fat is going to survive longer than the thin person, because the thin person will run out of reserves first.

Previous thread, although I don’t think it sheds any additional light - Fasting - can a Fat person live significantly longer than a thin person? - Factual Questions - Straight Dope Message Board

Is “no solid food” the same as “no food” in your example?
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Elderly people who are mildly overweight have a lower death risk than people of a healthy weight.

Potential causes include what you describe, if they get sick they have more fat mass to eat off, but also because elderly who have more muscle mass are more resilient.

Theres speculation that the elderly with serious diseases (cancer, etc) will skew the normal weight curve, but I believe they’ve controlled for that in some studies.

interesting. Thanks for all the replies.

I’m going to second this. I vaguely remember reading an article in Men’s Health that echoed all this.

An athlete is going to live longer than a skinny OR a fat person.

A vague memory of a magazine not known for scientific rigor is not a good cite. In a famine an athlete is definitely not going to live longer than a fat person, they might even live shorter than the skinny one, as they’ll be starting with a higher base metabolic rate and likely have abnormally low body fat.

Once the fat is gone they will start burning muscle mass, but muscles have a lot less calories than fat, with fat being twice as energy dense as protein and muscles having less protein by mass than fatty tissue has fat. And burning muscle mass is a lot more problematic for the body than burning fat.

“Alone” on the history channel is both entertaining and insightful on this topic. I highly recommend it.

Slight spoiler related to thread: the fat guy/girl almost always does better than the athlete.

Let’s bring some facts to this discussion, rather than opinion.

As I said, the relationship between weight and metabolism is complex, and depends on total weight, percentage of body fat, activity level and other factors. However, we can at least get an idea of what a 60 pound difference in weight means in terms of reserves. The calculations below are back of the envelope, and just intended to give a rough idea of what these might be.

Let’s assume two males, each 5’10", 40 years old, and in good health. They both have the same muscle mass, but one weighs 160 pounds, while the other is carrying 60 additional pounds consisting exclusively of fat deposits. Because they are in starvation mode, both have reduced their activity as much as possible in order to conserve energy.

Fat contains 9 calories per gram (compared to 4 calories/g for carbohydrate and protein), so that a pound of fat contains about 4,050 calories. However, fat tissue does not consist entirely of fat. According to this site, a pound of body fat contains between 3,436 to 3,752 calories. Let’s call it 3,600 calories. Therefore 60 pounds of body fat contains 216,000 calories.

According to this calculator, a sedentary 40-year old 5’10" male at 160 pounds needs 2019 cal to maintain body weight, while one at 220 pounds needs 2,468 calories to maintain body weight.

At 2,468 calories per day, the 60 pounds of fat represents 87 days of reserves, or almost three months. Of course, the actual survival is going to depend on other factors, but that’s a massive difference in potential survival time.

The example of Angus Barbieri cited by biblophage above lost about .72 pounds per day during his fast. Based on that, the individual with more fat will take 83 days to lose 60 pounds, in the same ballpark as the calculations above.

If you’re going to contend a thinner person will survive longer than a fat person, you’ll have to give some detail on the assumptions and physiological processes that would overcome that massive difference in the caloric value of reserves.


We haven’t discussed the “famine” aspect of this question. How localized is this food shortage? Are we just sitting, waiting for rescue? Is there food 50 or even 100 miles away? If so, I’d still like to be at 160 pounds with the possibility of making my way to this location. Walking with only a supply of water would give me a fair shot. At 60 pounds over weight, I don’t think I could make that distance.

That’s not something asked in the OP. But no, someone who is only 60 pounds overweight and otherwise healthy is quite capable of walking that far. You seem to think someone that much overweight is vastly incapacitated, and that’s not nearly the case. I’m not sure why you think being overweight means you’re a virtual cripple. I also don’t know why you want to redefine the question in order to find a way for the 160 pound person to come out ahead despite the enormous advantages in reserves the overweight person has.

I realize I have altered the original question, but I did so to suggest an instance where there may be a different answer. The OP did not specify whether or not that the individuals were just sitting around waiting for help or for the crops to finally ripen or if they had the option to try to escape the situation somehow.
A person in good physical shape could cover the 100 miles a lot faster at 160 pounds and reach the food source before he/she dies. At 60 pounds over weight, I believe the individual is going to be hard pressed to make the long journey in time to find the food. And I’m having a little trouble equating 60 pounds over weight with being “otherwise healthy”. I have friends that are around 220 and they literally could not walk 100 miles to save their life.