What would you say if I told you I knew an easy way to lower your body mass index, cholesterol and blood pressure; reduce your risk of coronary artery disease, stroke, diabetes and colorectal cancer; help you lose weight; reduce the number of medications you need to treat chronic diseases, and lower ischemic heart disease mortality rates?

And what if I – a butcher, a chef, an author of meaty books and the chap behind Meatopia – told you the secret was a plant-based diet? You'd probably think I'd lost the plot.

But as it happens, I'm a bit of a closet vegetarian and eat little meat at home. There, I've said it. Okay, maybe I'm a bad vegetarian – my diet is more akin to what is becoming known as 'plant based'. I first came across this idea on a health retreat in Thailand, where my physio would regale me with his eating habits while pulverising my particularly disobedient muscles, (such as they are).

At the turn of the millennium it was estimated that 4 billion people live primarily on a plant-based diet, or roughly two thirds of the planet

He had managed to combine Ironman competitions with a semi-vegetarian diet, eating mostly vegetables with very occasional chicken and fish. The idea that a man of a similar age to myself could compete at this level, without large amounts of bioavailable (easily accessed) protein, fascinated me. I consequently set out to research plant-based diets and then adjusted my own eating habits accordingly.

And it seems I'm not alone. At the turn of the millennium it was estimated that 4 billion people live primarily on a plant-based diet, or roughly two thirds of the planet. As a species, we have evolved as opportunistic eaters, subsisting on this plant-based diet, supplemented with fish and meat when possible.

So, what exactly is a plant-based diet? In essence, it's a diet of foods derived from plants, including vegetables, whole grains, legumes and fruits, but with few animal products.

The use of the phrase 'plant-based diet' has changed over time, and examples can be found of the phrase being used as a euphemism for vegetarianism or veganism. It was originally adopted to take emphasis off the word vegan; at the time often associated with being too extreme a position, based exclusively in animal rights, rather than a health rationale.

Here I prefer to use the phrase 'plant-based diet' in its truest sense, to refer to diets including varying degrees of animal products. I'm defining 'plant-based diets' as, for example, diets that include generous amounts of plant foods and limited amounts of animal foods, and as diets rich in a variety of vegetables and fruits, legumes, and minimally processed starchy staple foods and limiting red meat consumption. There's a clear distinction between 'plant-based' and 'plant-only'.

I'm so convinced this is the way forward that my future plans will almost certainly lean towards plant-based concepts

As an ethically minded consumer, I'm alarmed and somewhat embarrassed by our animal protein consumption, and I have more to lose here than anyone, having built a career on it. However, there is more to this than one's health. As a restaurateur and butcher, I'm all too aware of the prices of properly, ethically reared meat and fish, and they are only going one way.

The truth is, we cannot continue to eat meat and fish at the rate we are currently consuming it. The options are clear; either we eat the intensively farmed, unethically reared meat and fish that we know are ultimately unhealthy for us, or we return to valuing protein as a bit part player in our food – an occasional treat – much as our ancestors did.

I'm so convinced this is the way forward, albeit perhaps some way off, that my future plans will almost certainly lean towards plant-based concepts. I am, however, only part way in my journey. As a butcher and chef I still taste meat almost daily as part of my work life, but in my own time plant-based is what I want to eat, and every year I travel to Asia where I gorge on 'healthy' plants in an attempt to balance out a year's meat sampling.

In fact, while you're reading this I'll be back on that physio's table in Thailand, with aching muscles and a body that's survived on little but vegetables for a week. And feeling all the better for it.

When he's not gorging on vegetables and having his muscles pounded by physios, Richard is a butcher, a chef and an author (often about meat). 'Prime: The Beef Cookbook' is out now (Octopus).