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Wild Animals/Query re chimps and feeding habits


I hope you can help me with this conundrum:-
I am a RVAF dieter(one who eats an all-raw diet consisting of raw animal and raw plant food). While some genuine scientific info exists on the harm done by cooking and when cooking got started(c.300,000 years ago) and when cooking was practised on a worldwide scale(c.125,000 years ago), there is a crazed scientific kook called Richard Wrangham who likes to claim that cooking got started c.1.8 million years ago. Because he has no solid palaeoanthropological data to support his claims, he has made an absurd claim that raw foodists would need to chew their raw foods for many hours each day in order to get enough calories. He bases this absurd claim on the amount of time chimpanzees spend eating each day. I know for a fact that raw foodists like me actually spend much less time on meals than cooked-foodists as we do not have to spend so much time preparing or cooking our foods compared to cooked-foodists, and we RVAFers certainly do NOT have to spend several hours each day on eating. My question is this, therefore:-

How long do chimpanzees spend on eating, on average, each day?


Dear Geoff

Thank you for your unusual question. I also wish to thank the authors of the websites and books I used. As physiology is outside my comfort zone, I hope you will understand if some of my quotes are invalid.

Volume 6 of Marshall Cavendish Animal World says that chimps eat fruit for at least 4-5 hours a day. I don't know if anyone has measured how long chimps take to chew their food, but I suspect there is a lot of individual variation, depending on the food eaten and how impatient the animal is. Some people are meticulous chewers and some bolt down the same meals; I can't tell you if their metabolisms are adapted to this, but chewing food into smaller portions makes it easier for digestive enzymes to work on the food. Kate Mulcahy ( compares feeding processes, but says that chimps graze on fruits constantly while most humans eat no more than three times a day.  

Volume 3 of 'Handbook of Mammals of the World' says that great apes have simple, globular stomachs and lack fermentation chambers, so they can't digest large quantities of mature leaves or unripe fruit.Chimps use their mobile, muscular lower lip to separate and eject some fruit skins and large seeds. They also use this lip to compress food against the teeth and gums. They spit out indigestible parts of fruit, so these do not enter the digestive system. The authors also state that chimps will eat certain plants with a high concentration of fibre and other metabolites and will eat earth, which contains necessary minerals.

The human digestive processes are probably similar to those of a chimpanzee, but there are differences in the digestive system ( There is no reason why you can't have a diet of raw food and vegetables, although you should be careful eating certain meats as they could contain parasites, which would normally be killed by cooking. Please note that there are opponents to a diet of raw food (, but you know that already. Kate Mulcahy's comments lead me to the idea that while you may save time preparing and cooking food, but spend longer in the digestion process. I suspect that your RVAF diet is not the same as that of a chimpanzee, as i doubt that you eat soil for certain minerals and I also don't think you spit out food that you know can't digest properly, although I accept that I can be wrong on the latter two assumptions.

It may be worthwhile having periodic medical checks. I have had a few blood tests recently and these have indicated that I need to change my diet.

All the best


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Jonathan Wright


I can answer questions about wild mammals and other animals, as well as extinct animals and zoos. I am not an expert about every animal species. I can look up information from books and the internet, but can't verify if all the information is true. Please don't ask questions about: 1. Pets. I am not a vet. Please contact a vet if your pet is ill. You may need to spend some money if you want your pet to live. Don't get a pet if you don't know how to look after it and if you can't provide it with the space, food and possible companions that will help it live a healthy life. Don't take animals from the wild, unless they are ill and/or injured and you can protect them until a wildlife charity can help. It is cruel to take animals from their parents, especially if the parents will look for the babies, while putting their other babies at risk. You may be breaking the law by keeping wild animals or you may need a licence to look after some species. Please check with a local wildlife group. 2. Eggs: Please don't remove eggs from nests. The mother birds provide the right temperature for the eggs and won't sit on them if the temperature is warm enough for them to develop naturally. It is illegal to remove eggs of some species and, unless you have an incubator or a broody hen, the egg may not develop. If you are allowed to touch the eggs, you can candle them to see if they are fertile. If theys aren't fertile, they won't hatch. 3. Fights: Please don't ask about fights between different animals. These questions assume that individuals of two species fight each time they meet and that one species will always be victorious over another. This is untrue. There are cases where a live mouse has been fed to a venomous snake, bitten the snake leading to the snake's demise. 4: Diseases: Please ask doctors or other medical experts about diseases that you may catch from animals. I can't advise on how to deal with viruses, bacteria etc.


I have a zoology degree and have been interested in animals since I was two. I am a zoo volunteer at London Zoo. I have appeared on a BBC Radio Quiz, 'Wildbrain'.

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BSC degree in Zoology. 'A' level in Zoology. 'O' Level in Biology.

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