WAG:Yes, but only…
Till he died of malnutrition?
Ok well obviously the O.P. took it way too far to the extreme but how much longer would say a pretty muscular, but still with beergut 260 pound guy last than a 150 pound person of the same sex, if both had water?
Probably about the same. Beergut might have a slight edge, particularly if your 150 Beanpole has a low double digit body fat percentage, but I wouldn’t lay points on his surviving more than a day or two longer at best, all things being equal.
However, in an endurance/survival situation, where both parties are of equivilent aerobic health and are required to sustain continuous moderate activity (hiking, hunting, food gathering) and have a marginal intake of carbohydrates but little or no fats or fat-soluable vitamins, Beergut is going to have a definite advantage over Beanpole. Body fat is a way to supplement caloric intake during lean times, but not a complete replacement for it.
Stranger
260 lb guy would last considerably longer, but not in a direct, linear “he has x extra lbs= extra days” relationship as the metabolic demands of supporting his extra mass (while dieting) would take extra metabolic calories over the base metabolic level for the 150 lb man, and even this relationship is complicated by the fact that base metabolic rates (calories required per lb of body weight) are about 10% lower for people with an obese body composition vs non-obese as supporting fat takes less (relative) energy than supporting muscle.
That’s 10% lower per unit mass (lean muscle or fat, depending) though. An obese person will require more calories overall to maintain their metabolism, and burning fat (and lean muscle mass) to provide energy in lieu of sufficient carbohydrates is counterproductive. It’s not just the amount of raw calories available, it’s also the processes by which they’re obtained and the byproducts thereof.
Stranger
The big problem in diabetic ketoacidosis is that the blood glucose is sky-high – since there is no insulin, little glucose is transported into the cells, so it stays in the blood. It serves as an osmotic drag, sucking water out of the cells and into the urine. DKA usually starts when a diabetic gets a bit sick and isn’t drinking as much. It starts a spiral that ends in an ER with admission, often to an ICU.
Some non-diabetic ketoacidoses (I’m thinking alcoholic ketoacidosis) can be harmful, but most aren’t, as the blood glucose is normal or low. Ketones can serve as an osmotic drag, but not so much as sugars. They can also cause metabolic acidosis, but a normally functioning kidney should be able to compensate and retain bicarbonate to adjust (short term, though, the patient would breathe more, blowing off carbon dioxide to force blood pH upwards).
Anybody who has been on Atkins can tell you this works; in the hospital, they use a similar regimen for morbidly obese patients called a modified protein fast. If the kidneys are doing OK, you should be dandy. Just keep hydrated. For a prolonged period, more than a few weeks, you would probably want to add a multivitamin and fiber to keep things OK.
In that circumstance – a renally healthy 750 pounder versus a renally healthy 150 pounder, with appropriate monitoring, appropriate hydration, appropriate supplementation, I have no doubt that a 750 pounder would last much longer before protein malnutrtion set in. My suspicion is the one thing that would happen is that your breath and pee would smell funny and you would develop an enormous, enormous carbohydrate craving. There are stories about Prader-Willi children with BMIs > 50 on modified protein fasts ransacking hospital floors stealing bread and carbs from other patients’ meal trays. This especially happens if the kid gets a little carbs, like for instance birthday cake or something like that.
What do you mean by “appropriate supplementation?” Remember, per the OP, we’re talking about surviving “without food.” I take this to mean without accompanying vitamins and nutrients; strictly hydration and fat reserves.
Stranger
Well obviously, I thought I made that clear in
The 10% differential issue for differing body types was posed to illustrate that it’s not a simple linear relationship in calculating caloric needs.
I’d like to find out what people dying of starvation actually run out of first. All of the people in the 1981 IRA hunger strikes died between 46 and 71 days, with most dying in the 60-65 day range. This, to me, suggests that it isn’t about fat stores, but rather about other vitamin deficiencies, as you wouldn’t expect such a tight distribution with something as variable as fat stores.
With a multivitamin and maybe a salt pill, I think you could shift the limiting reagent to calories. Without it (and with appropriate hydration), I don’t know what would kill you. According to the SD column above, you would run out of vitamin C in 6 weeks, so this could be it, especially if it caused hemorrhage. I would also be worried about things like sodium and potassium, though – I think electrolyte imbalances could be really dangerous and certainly poor nutrition could cause these.
Well, I see it has brought one woman to the hospital. But for the non-obese guy to survive longer, ketoacidosis will have to kill the obese guy for certain. Otherwise he will just outlast the non-obese with his storage. (Or he could be killed by something else of course, but you only named this.)
I agree that we are not evolutionary adjusted to surviving for a long time without food. But that doesn’t mean we can’t do it.
That is not going to be a problem here at all. Eventually, there will be no blood glucose.
Henry VIII
See the link
Thinking about this question while falling asleep last night:
I think there may have been a People Kibble thread a while back where we discussed the essential nutrients necessary to keep someone alive.
In it, we discussed water, calories, vitamins, minerals (including salts), and certain essential amino acids (phe val thr trp ile met lys leu + his arg in children). The fat would get you calories but you would need to supplement the rest.
I don’t know if deficiencies of any one of these (vitamins, essential amino acids) would kill you before calorie malnutrition set in. I’m thinking, based on the IRA hunger strikes, that it would.
It is also possible to imagine a foul tasting “essential bar” containing the 10 essential amino acids, vitamins, and minerals, to be taken with 64 oz of water over a day, that could keep someone alive solely on fat stores. Taking appetite out of the picture, this would allow fat burning at the fastest rate possible.
Sure. If you can properly utilize the calories in stored fat, then the person who carries the most amount of fat will survive the longest. The question I’m addressing, however, is how long could someone survive on fat alone. Without supplementary nutrients, I don’t think the fat person will have a significantly longer survival rate than the healthy thin person. A 750 lb (obvioulsy obese) person will have other medical complications that will contribute to problems with a starvation diet. In general, carrying extra, i.e. obese, mass isn’t a benefit in any sense.
Stranger
ok, maybe 750 pounds is a bit much. It would be more interesting to look at someone who weighs, say, half that.
Can you point to some specific problems he might have? And I don’t think ketoacidosis seem sufficiently dangerous based on that one hospitalised woman.