steak
© Getty
Would you eat steak for breakfast, lunch and dinner?
Can man survive on meat alone? Doctors don't recommend it, environmentalists point out that it's probably unsustainable, and the more militant of the vegan army are quick to compare it to genocide - but the answer, apparently, is yes.

Advocates of the carnivore diet - a relatively new eating regime that involves ingesting nothing but meat, eggs and water (sparkling is fine) - claim results range from radical body recomposition to arthritis relief. But what about fibre? Isn't that too much fat? And, even if surviving on steak gives you the modern equivalent of superpowers, how can anyone possibly keep doing it - especially without the frites?

Let's start with the evolutionary angle. Many modern carnivores adhere to the theory that our ancestors ate mostly meat because it wasn't energy efficient to gather a lot of fruit or vegetables - leaving our bodies evolved to run optimally on a meat-centric diet. Tribal peoples including the Inuit and Maasai, they point out, have done just fine on a mostly-meat diet for generations.

However, the Inuit forage for berries occasionally, and there's at least some evidence that the Maasai have evolved specifically to thrive on a cholesterol-packed diet. Until recently, giving up on fruit, vegetables and grains entirely seemed - for most people - risky.

Still, it's true that, technically, you don't need vegetables to survive. The only essential macronutrients in the human diet are protein and fat - going 'zero carb', as carnivores sometimes call their lifestyle, doesn't present any immediate health risks. Fibre, they point out, is not an essential nutrient - and, depending on who you listen to, may actually impede digestion by loading up your colon with indigestible material.

Vitamins and minerals are trickier - technically, you can get more than enough of them from meat, but it's worth pointing out that the Maasai, Inuit, and our paleolithic forebears would have been munching on free-range, grass-fed animals raised in radically different conditions from all but the most pampered of modern cows, almost certainly changing their hormone and nutrient profile.

Plant-derived phytonutrients are another concern: there's significant evidence that they protect DNA. This might be part of the reason that diets high in processed meat have been associated with colon cancer in long-term observational studies: it's not the meat causing the problem, but a lack of greens. And this is probably the biggest reason to treat the carnivore diet with caution: advocates can point to anecdotal cases of individuals surviving for decades with no ill-effects, but there are (obviously) no long-term studies on large-scale Western populations trying it.

What about the short term? This is where things get... interesting. Dr Shawn Baker, one of the diet's most outspoken advocates, claims that he found it impossible to get lean eating a traditionally-healthy diet as he entered his late 40s, but now breaks age-group rowing records, while staying impressively ripped, on a diet of almost nothing but steaks.

Similarly, members of Reddit's Zerocarb community boast about improved energy and better mental clarity, while discussing stool consistency and exactly which seasonings are acceptable (salt is fine, pepper more hotly debated). Cravings, they claim, quickly depart, and hunger is rarely a problem - as long as you've got enough steaks.

Meanwhile, probably the movements' most famous adherent is psychology-professor-turned-bedroom-tidying-advocate Jordan Peterson, who claims that living on nothing but beef, salt and water has cured his longstanding depression, while his daughter credits the diet with resolving her arthritis. Other members of the carnivore community report relief from a host of serious autoimmune and digestive problems, while still others report radical weight loss.


It's this latter set of results that make a few medical professionals willing to recommend carnivory, at least in the short term: by helping to control inflammation and effectively cutting out sugar, there is some evidence that it can treat serious conditions, if used sparingly. In the long term? Caveat carnivore: if you feel good on the diet, it's really about what level of risk you're willing to accept.

What of the environmental angle? Hardcore carnivores claim that the widespread adoption of a steak-only diet would only improve the efficiency of livestock-farming, while wooing vegans with reminders that plant-based agriculture kills even more rodents and birds than carnivores kill cattle.

Are these arguments convincing? Honestly, it depends on who you listen to - Baker is quite charming in interviews - but it's undeniable that right now, with methane emissions from cows outstripping those of cars, something radical would have to change for the carnivore diet to work on a global scale.


Comment: Something "radical" like adopting traditional farming methods and getting rid of factory farming.
See: 'Lunatic farmer' Joel Salatin: The rise of rogue food


Ultimately, there's no telling whether going carnivore can be beneficial for us over a sustained period - though if you're thinking about society rather than individuals, the available evidence points to 'no.' Would it work for you? As with any diet, just the fact that you're restricting your own eating options is likely to work wonders in the short term: cut out processed food, sugar, gluten and lactose all in one hit, and something's bound to change, probably for the better. Eat, as some zero-carbers do, three McDonald's patties per meal and you probably won't do yourself any favours; feasting on steaks from unhappy, cage-raised cattle is unlikely to do much better.

If you've got a serious condition - Crohn's, Lyme disease, otherwise-unfixable anxiety and depression - and you're prepared to take a gamble, it might be worth a 30-day experiment, done with an appropriate amount of reading around the subject first. Otherwise, the best advice is the same as ever: eat real food, preferably from happy animals. And don't beat yourself up if you occasionally want some frites.