Food & Wine
Is a meat-only diet healthy?
Though meat-only diets have been endorsed by celebrities claiming it has cured them of chronic diseases and kept them lean, health researchers find it a bit suspicious.
The diet goes against the Australian dietary guidelines, which recommend a higher consumption of fruit, vegetables, and grain foods, and cutting down on animal products to just a couple of servings a day.
But would you be able to get everything you need from an all-meat diet?
It kind of works on paper
The carnivore diet takes the same low-carbohydrate approach of paleo, keto and Atkins diets to a new extreme, cutting everything save for animal products.
There are variations, where some people only eat beef, others eat a wider variety of meat, and whether cheese and butter can be included on the menu is up for debate among followers.
But, if we just consider whether you can get all the nutrients your body needs from only animal products, is it possible?
Yes, or pretty close to a yes, says Veronique Chachay, a nutrition scientist from the University of Queensland.
After testing different versions of a carnivorous diet using dietary composition analysis software, she found that, depending on the specific mix of animal products in the diet, most of the vitamins humans need were accounted for.
“From a purely micronutrient point of view, we can’t say people cannot meet their requirements,” Dr Chachay says.
But, box ticking on nutrients is only one part of maintaining good health. Fibre is known to play an important role in digestive health, fostering a diverse population of health-promoting bacteria in the gut - and this key food is absent from carnivorous diets.
Experts are keen to understand more about the science behind why some people report feeling good while on these diets, even after a long time.
Looking to the Inuit diet for answers
Many indigenous groups from Northern America have a traditional diet almost entirely consisting of animal products.
The traditional diets the Inuit and other Arctic people follow is often used as evidence to support the argument that a carnivorous diet can be healthy.
Researchers who surveyed Indigenous communities in Canada found that community members ate more than a kilogram of animal products a day, and between 28 and 160 grams a day of plant foods.
The research showed it is possible to live on an animal-heavy diet, says Clare Collins, a professor of nutrition and dietetics at the University of Newcastle.
“[The Inuit people] had a really low carbohydrate intake, a really low vegetable intake on their traditional diet, and they ate some stuff that we wouldn’t eat, for example, they ate the organs of a lot of animals, they ate a heck of a lot of seafood, and they ate some of their meat raw, which is actually higher in vitamin C,” she says.
“With some of the nutrients, because they ate a lot of these foods, they could meet their requirements.”
But, Inuit people don’t have especially long lives. Though the factors that impact life expectancy can be tricky to identify, especially when studying First Nations people during modern times, Professor Collins says diet plays a big role.
“Life expectancy is not high and they have very high rates of some cancers. It’s partly attributable to their genetics. And that’s exacerbated by a really high salted, smoked food diet.”
She also points out that the traditional diets of the longest-lived peoples in the world include a very high vegetable intake.
No matter which diet you look at, they all share a common factor: “They’re all less refined foods,” Professor Collins says.
“And that’s a big thing that people don’t really want to look at.”
No single answer
While proponents of the meat-only diet, and all the diets that came before it, say that they are the ideal way to eat, Dr Chachay says there is no one optimal diet.
Differences in our genetic makeup mean that personalised diets could be the way of the future, and Dr Chachay hopes it could even be personalised to the makeup of our individual microbiomes.
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