My characters get trapped in a universe where Apes, specifically chimpanzees, rule supreme and humans are just wild animals. Like most wild animals, humans are often taken from jungles and rain forests and put in zoos. My main characters are all captured by hunters and taken to a zoo in a metropolitan area. They are kept in an enclosure, where they are fed about twice a day. The diet humans are given at the zoo is

  • 3 Mangoes

  • 500 Termites

  • 6 Celery sticks

  • Unlimited amount of water

The humans in that universe are less picky and more resilient when it comes to eating, but the humans from this universe aren’t like the ones there. My question is, how long could the humans survive on this diet?

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    $\begingroup$ Outside of the lack of essential minerals, fats, protein and amino acids, the main reason the humans will die is simple lack of caloric intake. A normal person needs about 2000 calories/day to survive and function normally. Without calculating the total caloric intake it is hard to estimate just how long a human could survive before starving to death (and they may die much sooner due to the lack of essential nutrients before that). $\endgroup$
    – Thucydides
    Jun 21, 2018 at 3:25
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    $\begingroup$ You should edit your question to link to your other question. Also why dont you rephrase it as "what is the minimum diet humans can have with mangoes,celery, and termites" . Include too "is there a nutritional void in my supplies? If so, what is the most viable nutrition given x environment." If youd like, i can make heavy revisions to this post. Ive seen your other question and I think i know what you are attempting to ask. $\endgroup$
    – Crettig
    Jun 21, 2018 at 5:01
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    $\begingroup$ @SydneySleeper That's because too often they get story-based wrong. $\endgroup$
    – a4android
    Jun 21, 2018 at 5:17
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    $\begingroup$ if this is what they're giving their caged animals, it's a wonder there ARE any caged animals at all $\endgroup$ Jun 21, 2018 at 6:15
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    $\begingroup$ -1 for lack of any own research. Calculating calories is trivial. Termites was discussed on this very site, mango and celery is trivial. Calculating protein and fat intake doesn't take much longer. $\endgroup$
    – Mołot
    Jun 21, 2018 at 7:27

4 Answers 4


Your diet provides humans with enough calories and vitamins and minerals from 6 per day mangos @ 210 calories per mango, depending on their body weight and activity, to survive for many years. But you are only providing ~1 gram of protein per day from their ration of termites, ~ 8 grams from the mangos, and 1/2 gram from the celery. The human body needs 0.8 grams of protein per kg of mass every day. If it doesn't come from the diet, it comes from the body.

So on average, an adult male doing nothing will consume 43 g of body mass every day. The typical male has 30 kg of muscle and 10 kg of fat. Every hundred days they'll lose 3.3 kg or 10 kg per year. Assuming a healthy adult male, they'll survive at most < 4 years. More likely 2-3 1/2 years. This is assuming they are doing nothing but eat and sleep to conserve energy.

If they are active, then they'll burn their bodies faster and die sooner. And, it assumes that they don't have any latent diseases like a dormant cold or flu. Once the body weakens it won't be able to fight infections or diseases.

Living in alien zoos they are likely to be in contact with many viruses and bacteria they've never encountered so their immune systems will be in overdrive, which will also shorten their life expectancy under these conditions.

I think on this diet though, the most likely cause of death will be either suicide or cannibalism. But, it is hard to guess how long either of those will take to rear their heads.

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    $\begingroup$ I feel that the lack of fat in that diet can also be a problem. I don't know whether there is consensus among the nutritionists, what exactly the fat is for, but I vaguely remember it being necessary for proper production of hormones and antibodies. Just give them some nuts at least. $\endgroup$
    – Cumehtar
    Jun 14, 2019 at 19:54
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    $\begingroup$ @Cumehtar It's called protein poisoning (en.wikipedia.org/wiki/Protein_poisoning), and, as far as I remember, has to do with certain fat acids not being released into the body if the body doesn't burn any fat for energy. That later information is not found in the wikipedia article I linked, it must be found somewhere in an article about some of the fat acids involved (if my memory serves correctly). $\endgroup$ Jun 14, 2019 at 20:16
  • $\begingroup$ @cmaster nice, so it's a contest of whether this or kwashiorkor gets those humans first. Ouch... $\endgroup$
    – Cumehtar
    Jun 14, 2019 at 20:29

Not very long.

Termite workers weigh in at 0.9 milligrams. 500 termites is 450 milligrams (less than half a gram). For perspective, 1 gram of water is 1 cubic centimeter. To equal the meat in a McDonalds' quarter pounder, you would need at least 113398.1 milligrams, or 126,000 termites (+/- a negligible percentage).


Not a good diet at all. There are a few issues here I see. First is your number of termites is a few orders of magnitude too small to be a significant source of anything. If you increase it as pojo-huy suggests, it would round your diet out a bit, but that still doesn't make it a great answer. This is because zoos don't just feed their animals what people eat, they try to make specialized feeds with 3 general goals in mind:

  • Keep their animals healthy.
  • Maximize their limited budget.
  • Simplify care through minimal prep work.

Warmer Climate: Wheat and Beans

The ideal solution to answer all 3 of these concerns was already figured out by humans 1000s of years ago back when agriculture struggled to make enough food to survive. The ideal cereal grain for a limited diet is wheat. Wheat has more vitamin-C and Omega-3 than other cereal grains meaning you don't need to supplement it with fruit and meat to reach your dietary needs. Which bean you pick matters a bit less. Most of them will fill in what wheat is lacking in. A common misconception about wheat is that it is mostly empty calories, but that is not true. Modern milling practices make flour mostly empty calories because they extract all the good nutrients from the flour to keep it from spoiling. But whole, unprocessed wheat is practically a balanced diet all on its own. Just boil it whole, or mill it when you are ready to cook with it, and you get its full value.

Another nice thing about wheat and beans is that they grow very well when planted in rotation. While wheat and beans may be a bit less calorie dense and a bit more labor intensive to process than some other crops, they have very low failure rates and store very well, and this lack of attrition makes them the cheapest option. At current bulk rates, you can feed a human for just $0.52 per day plus the labor of meal preparation. So with Wheat and beans, you can keep your humans healthy with minimal cost and complexity.

Colder Climates: Potatoes & Eggs

If you live in a colder climate, the failure rate of beans and wheat goes up significantly taking away thier biggest advantage of being reliable crops. In such colder regions, the ideal solution is potatoes & eggs.

Potatoes have nearly all of the nutrients we need for survival and they have the highest caloric return for the amount of farmland used out of any known plant. They are much more vulnerable than wheat to warm weather based crop and storage failures, but as long as you live somewhere cooler, they can produce an even better return on your amount of land and labor than wheat and beans.

Potatoes also lack some of the vitamin D & A you get from a bean/wheat diet, and dietary vitamin D becomes extra important in colder climates where your body produces less of it from the sun. Eggs come in as a cheap way to supplement what potatoes lack. They are really easy to cultivate compared to other animal products, and they contain the important vitamin D & A that potatoes are lacking in.

Just eating potatoes and eggs will keep you alive and healthy for a pretty long time. But, there is a catch. Neither are a good source of calcium... or are they? Eggshells are the basis for most calcium supplements. So to prevent calcium deficiency, all you need to do is grind the egg shells into your feed and you have a complete diet.

The cost of feeding chickens and shorter shelf lives of eggs makes this more expensive than the wheat and bean diet at about $1.50/day, but if you live where there is less sunlight, the cost of locally sourced food being higher is just a given.


The body can survive roughly ~3 weeks without food some longer: https://www.healthline.com/health/food-nutrition/how-long-can-you-live-without-food#individual-time-period

But 3 days without water, and 3 min without oxygen. (well likely 4 but reads better is all 3s).

So given this list of food provided twice a day, a good while, but the lack of essential nutrients would probably catch up with them eventually. May be a few months. I would worry most about lack of salts. Given this is meant to be a zoo, I would expect them to offer a slightly more balanced diet to their charges.

  • $\begingroup$ I'll always challenge that 3 weeks figure. Some religious people fasten completely for 40 days, and they routinely survive. As long as you keep ingesting enough salt (replace what you sweat out, otherwise your body looses its ability to retain the water you drink, leading to dehydration) and you have enough fat and protein in your body, you can starve for quite a long time. $\endgroup$ Jun 14, 2019 at 20:22

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