What would humans eat in a zoo?

Photo Credit: Humphrey King via Compfight cc

There’s been a lot of debate recently—well, in the past 50 years—about what human beings should and should not be eating. As a recent article by Dr. David Katz points out, we know what to feed animals in zoos. Why do we have such a difficult time feeding ourselves? Most advice rests on continuing to eat the food groups available to us, but just in moderation. That clearly isn’t working for a lot of us. So what’s missing?

The newest in a long line of diet guidelines is the Paleo Diet, which asks us to imagine ourselves as cavemen and eat only what a caveman would have been able to find. As far as guidelines go, that’s pretty good. It’s not far off from “If your great-grandma wouldn’t recognize it, don’t eat it.” At its most basic, it’s eating what you can find naturally. That’s pretty broad, and can be interpreted a lot of ways. And in some ways, that’s great-- it can be applied to many different ethics, cultures and value sets fairly easily. In practice, it’s usually not hard to answer whether we would have been able to eat it. Doritos? Not natural. Eggs and spinach? Easily foraged, that’s a go. Whole wheat bread? We would have had to invent agriculture for that, so also a no.

There are some inherent problems with this way of thinking. It’s broadness can lead to some huge swings in interpretation. If you want to take it beyond just a guideline, and make it something to seriously live by, i.e. an actual set of rules, it’s helpful to know what we actually would have eaten as cavemen. Anthropologically speaking, not just in the land of imagination.

Let’s start by looking at our closest living ancestors, the bonobos. They’re a ground-dwelling primate similar to chimps, but their social structures operate more like ours. They’re omnivorous, mostly eating fruit they can pick off trees and bushes, but also forage and eat leaves, and sometimes smaller animals like squirrels, rodents and bugs. What about chimpanzees? They’re a bit more aggressive as a species and have been known to hunt, so they have a more evenly omnivorous diet than bonobos, but eat roughly the same things.

Applying this behavior to humans, one can infer that the human diet would consist of foraged foods, small animals and insects. We probably ate more fruits in the summer, fattening ourselves up, and then ate calorically and nutritionally dense animals in the winter. Though it’s probably safe to say that the difference between summer and winter wasn’t jungle hot versus ice age wooly mammoth cold, so don’t go crazy. 

Depending on the region of the world your ancestors lived in, the proportions of the diet probably varied a lot. If you’re looking at a more nomadic “caveman”, it was probably a lot more meat from following the herd. If you’re looking at humans that lived in coastal or tropical areas, it was probably a lot of fish, shellfish and sweet fruits.

They probably ate slower, too. Try sitting down with a bowl of shelled walnuts and eating a handful versus cracking them open and eating them one by one. You get full after about 5 when you’re shelling them, but with them already shelled it’s easy to stick a couple handfuls in your face. Imagine finding your berries and picking them off the bush one at a time.

Seems easy enough. But there’s another logistical issue with this diet: Since the advent of agriculture, we’ve bred and chosen the fruits and vegetables we like to eat to make them the biggest and tastiest. I’m not even just referring to GMOs and factory farming. The modern yellow banana with its super sweet soft flesh is nigh unrecognizable when compared with its starchy ancestor. Even tomatoes, formerly small, lumpy, purplish bulbs, look alien versus their rotund, spherical and perfectly red modern counterparts. The guideline of “if your great grandmother wouldn’t recognize it, don’t eat it” probably wouldn’t realistically apply to nearly any of our produce available today. Comparing ancient bananas to current bananas is more like comparing an arctic wolf to a chihuahua. If we want to eat like cavemen did, the supermarket selection is already completely beyond the pale. So rather than just eat any fruit or vegetable we can find today, we’ll have to be more selective to balance out nutrition for breeding.

And then, of course, there’s exercise. The good news is that primates enjoy a lot of meandering with short bursts of strenuous activity, and lots of naps. So the good news is, running 3 hours a day probably isn’t ideal to mimicking how our ancestors moved. And getting tired in the afternoon? Totally normal. The problem is, even that amount of activity is more than what most people do, and lucky is the person who has the luxury of afternoon naps.

So how do we realistically apply these points to the lives we’ve manufactured for ourselves?

For starters, we need to eat a lot more plants. Unfortunately, we’ve bred most of our fruit to basically be candy, so a lot of that is out. Citrus fruits and berries are still pretty close to what they originally were, so they’re good. Super sweet fruits like bananas, mangoes, grapes…. Not so much. Still better for you than cake, but they’ll probably make you put on a bit of weight. That leaves vegetables. White potatoes are also overbred, so pick the ones that are more nutritious, like white sweet potatoes and yams. Dark green leaves are fantastic, as are squashes and cruciferous vegetables like broccoli and Brussels sprouts. If you have the luxury of growing or foraging organic nettles and dandelion greens, more power to you. Radishes, celery, carrots, mushrooms, bok choy…. There’s really quite a selection to choose from. The agricultural phenomena we’ve created would, however, be out: soy, corn, grain, potatoes.

What about protein? My guess is that most of you aren’t on board with eating bugs, though I would highly recommend them. Most wild animals are pretty lean meat, with less than 10% body fat. Lean cuts of any meat will probably count, but grass fed is best as that’s the herd animal’s natural diet. The nutrition the animal eats is the nutrition you eat in turn. Fish is also a good source, as are eggs from free range chickens that are allowed to peck and forage. There’s evidence that cavemen got a lot of nutrition from organ meat, such as stomach, liver and brain. I’m going to venture that’s out of the picture for a lot of you too, but again, very nutritious if you’re a meat eater. Interestingly, as the contents of the stomachs of animals would sometimes carry fermented dairy (calves) or fermented fruit (small monkeys and rodents), yogurt, soft cheese and wine could occasionally be on the list. If you’re getting technical, of course.

Cooking? Eating raw, steaming and roasting with limited oil are ideal. Remember we didn’t have oil until the advent of agriculture, and animals were pretty lean in the body fat arena. If you need to use oil, use the ones that can withstand the heat and didn’t have to go through a lot of processing to be created. Coconut oil, butter and animal fat. Olive oil and avocado for cold dressings.

There are trimmings to the tree that we could add that are still super nutritious, and some that are superfluous but make life that much more interesting. Cocoa, coffee, spices, herbal teas, flax oil and flax seeds, powdered spirulina and wheatgrass, gelatin, are all full of antioxidants and a great way to boost the nutritional value of your food. Nutrition, unfortunately, is also lost with modern agriculture. Supplementing with some whole foods additives like those listed is sometimes necessary, but also enjoyable.

And what about sweets? We may have had occasional access to honey. Wine is not entirely unimaginable. But these are more occasional treats than regulars. For sweeteners, it’s probably best to stick to eating straight fruit, stevia or sugar alcohols that won’t spike your insulin.

And of course, exercise. You can’t really leave your desk to roll in the grass, but there are things you can do to counter sitting all day. If you have a job that requires movement and manual labor, you’re already ahead of the game. You could maybe do yoga or 20 to 30 minutes of strength training 3 to 5 times a week to feel at your best. For those of us tethered to a computer, or sitting on our couch at length at the end of the day, start incorporating long walks into your daily activity. Play outside with your kids. Go for short high-speed runs (HIIT and interval training are great primers for this). Walk or bike to work. Convert your desk to a standing desk. Go for walking meetings. Move around the office to chat with your coworkers instead of sending an email, stand to make phone calls. Just move around more in general. And the naps? If you have the luxury, take a 15 minute nap on your lunch break or in the afternoon instead of that third cup of coffee.

Vegetables and leaves, citrus fruits and berries, a few nuts and seeds, limited oil, lean meats, eggs and fish. Bugs and organs if you’re game. Possibly yogurt, cheese and wine on occasion. That’s what we’d eat in a zoo. Abundant, yet at the same time austere. No worries about calorie counting or logging long runs. All in all, as a diet it’s pretty forgiving. The amounts of protein and vegetables are probably a bit variable, but I would err on the side of far more veggies than protein. Eat slowly and mindfully. Move around more. Allow time for short siestas. And above all, keep it clean. :)