快猫短视频

IF YOU have ever delved into the world of online diet advice, you might have heard the claim that modern fruit is so filled with sugar that it is unsafe for zoo animals. It might have come with links to media reports with headlines like 鈥淶oo bans monkeys from eating bananas鈥�.

The claim that fruit is no longer a healthy part of the diet 鈥� for humans as well as animals 鈥� has gathered thousands of likes and shares from low-carb devotees around the world. But how good is the evidence behind these claims?

As a botanist who knows rather a lot about fruit, but very little about monkeys, I decided to go straight to the source, and talk to the zoologist whose work first spurred these stories.

Amy Plowman is director of living collections at Paignton Zoo in Devon, UK, and has done pioneering research on the diets of non-human primates in captivity. She observed that the food given to zoo monkeys was often a poor reflection of what they ate in the wild. In some zoos, it more closely resembled the food preferences of their human keepers.

鈥淲e have, whether consciously or unconsciously, assumed that human food is suitable for non-human primates,鈥� she says. In some leading zoos, primate species whose diet in the wild is made up overwhelmingly of leaves are routinely fed chicken, eggs, cheese, yogurt, bread and noodles. This understanding of primate nutrition is, Plowman says, 鈥渇ar removed from reality鈥�.

To create a diet as similar to the monkeys鈥� natural diet as possible, she eliminated energy-dense items such as meat, dairy and grains, and reduced the amount of fruit and some of the more calorific vegetables. The monkeys鈥� new regime consisted essentially of specialist primate feed pellets, leafy veg and fresh tree leaves.

In a very short time, Plowman and her team noticed dramatic improvements in the animals鈥� health, with reduced obesity, improved dental health and even behavioural improvements. The press enthusiastically reported the story, focusing almost exclusively on the angle of zoo monkeys no longer being fed bananas. When other institutions, such as Melbourne Zoo, started to follow suit, it triggered a further flurry of headlines.

These news reports rarely mentioned that many of the animals involved in these new feeding regimes, such as the red pandas in Melbourne Zoo, are essentially leaf eaters and don鈥檛 actually eat much, if any, fruit in their natural habitat anyway. But then, pandas being fed bamboo instead of fruit is less of a story.

鈥淭hese conclusions require us to ignore one small detail: humans aren鈥檛 zoo monkeys鈥�

Those who linked the switch to the benefits of particular diets in humans also failed to point out that the new regime given to these animals involved eliminating all meat and dairy too, and swapping to an essentially 100 per cent leaf diet. Advocates of ultra-low carb and meat-heavy 鈥渃arnivore鈥� diets for humans were therefore sharing research whose findings were contrary to their claims.

What does Plowman think of this interpretation of her findings in zoo animals being used as justification for excluding fruit from human diets? 鈥淚 wasn鈥檛 aware of this and find it very surprising,鈥� she says. 鈥淔ruit and non-leafy vegetables have a much lower energy content than most of the foods available to humans, so are a very healthy option for us given most of us consume too much.鈥�

Stressing that her work on zoo animals couldn鈥檛 be translated to humans, she went on to say that the dietary alterations she made were to replace foods higher in sugar and starch with indigestible fibre, not replace it with fat and protein. There is plenty of evidence, she says, that a switch from starch to fat and protein is 鈥渄efinitely not鈥� a good thing.

The evidence suggests she is right. In several exhaustive reviews of the best scientific studies we have to date, higher fruit consumption has been consistently linked to a of , as well as a reduced risk of cardiovascular disease and of cancer.

Perhaps more pertinently, if you or I were put on a leaf-only diet we would need to eat more than 300 cups of chopped, raw lettuce a day. That wouldn鈥檛 be pretty. We would struggle to get anywhere near enough calories to meet our daily needs, and would quickly succumb to nutrient deficiencies.

It seems, much like zookeepers of the past, our close-relatedness to monkeys means many of us, low carb activists included, can鈥檛 help but project their needs onto ourselves and vice versa. But to do so requires us to ignore one small detail, which even I as a botanist can confirm: Humans aren鈥檛 zoo monkeys. Shocking, I know.