Hearn is something of a serial entrepreneur. He founded an internet marketing business in 2008 and sold it three years later for 2.5m. And when he came up with the idea of Huel, he was attempting to set up a comparison website for dietary programmes.

The idea was that people are never quite sure who to believe when it comes to diets. So my logic was that youd run people through different diets, would show the results and then it would be like a price comparison site. At the end, youd click on the link and would buy the programme.

But it was incredibly time-consuming and expensive to produce even one of these programmes. I was one of the guinea pigs. My goal was to go from 21% body fat to 11% body fat and it meant I had to cook all my meals from scratch and calorie-control everything. I was also eating a lot of fresh meat to get the protein, but it did work. Friends were asking me how to do it for themselves but of course theyre very busy and just dont have the time for all that. So I had the idea that there should be an easier way of getting this complete diet in a more time-saving way.

He brought in James Collier, a sports nutritionist, as a co-founder and he developed what they describe as an all-natural, vegan formula made of real food. According to the website, the ingredients include a carefully chosen blend of oats, pea protein, flaxseed, MCTs from coconut, sunflower lecithin, sea salt, a bespoke vitamin and mineral blend, vanilla flavour and a sweetener.

But when I talk to Joanna Blythman, an investigative food writer who has written five books on the food industry, she scoffs at the idea that the ingredients are natural.

There is almost nothing in there in its natural form. These are very, very technologically altered hi-tech ingredients. Theyre the opposite of what whole, natural foods are. If I read that list of ingredients on a product on a supermarket shelf, I would have a major problem.

Look at the eighth item on the ingredient list. Its called a vanilla flavour system. I mean, seriously, what is that? Its not vanilla extract or vanilla pods or vanilla grains or even vanilla essence. You are talking about the very rarified regions of food processing and industrial food chemistry where basic ingredients are being mucked around with and transformed. There are these very intense chemical sweeteners in there. Theres sucralose; thats something like 200 times sweeter than sugar. Theres maltodextrin thats another sweetener. And xylitol thats another one. Its all just rubbish. And then theres pea protein, which sounds good, doesnt it, but what the hell is it? Youre treating peas with a number of complex, chemical reactions to extract some sort of beige powder.

If I had to eat this, Id lose the will to live pretty quickly.

Shes not the only one. I have a friend to stay and in the morning I lay out muesli, yoghurt, peaches and plump ripe cherries. And then mix her a glass of Huel. And there it is again, what Ive come to think of as Huel face.

Catherine Collins, the principal dietitian at Londons St Georges Hospital NHS trust, tells me that her immediate response to the list of ingredients is that just because you can doesnt mean you should. She calls the formulation interesting and compares it to a milk-based version we use for very sick patients as a tube feed. Its what it reminds me of too Complan, the powdered sachets that my mum tried to make my dad drink when he was having chemotherapy and couldnt stomach ordinary food.

It does raise the question of why youd want to eat that when youre not desperately ill, but there are takers. On Twitter, I find a Swiss software developer, 36-year-old Nick Balestra, who tells me hes been eating nothing else for the past twoweeks.

I used to work remotely at home and I had time and all my things around me. But now Ive moved to London and its a big effort to find the time to cook in the evening and to prepare food to bring into the office. I have a very healthy lifestyle and I like eating healthily. I read about it and thought Id give it a go.

How are you finding it?

Its super good. I kind of even like the taste. Its very oaty. Its like having porridge or similar. At first, people at work looked at me like I was an alien. They were like, Are you sure? And, Do you want some normal food? But then you tell them about it, how you save time and money and how its totally healthy. I have a colleague whos a super-sporty guy and hes just ordered some. And even my girlfriend, she quite likes it.

The trick, he says, is to use less water and eat it like porridge with banana and cinnamon.

I ask Hearn about the extreme sweetness. Its very difficult to get right. Weve done research and we have an equal split of people saying its not sweet enough and those who say its too sweet. And the aftertaste? Its difficult to define. It could be the peas and rice. Its a natural, earthy taste. Or it could be sucralose, though its not really an aftertaste.

He arranges to send me the unflavoured version and suggests using a blender, making it with ice and adding coffee or fruit to it. I have one guinea pig left. My running partner, Catherine, is exactly the type of person who drinks protein shakes for breakfast. I mix two versions: one is the vanilla powder with fresh blueberries and one is the unflavoured version with a bit of honey and fresh raspberries. At the end of our run I pull them out of my rucksack.

She tries the blueberry one first. Whats in it? she says. Sucralose. Maltodextrin. And xylitol, I say. And a vanilla flavour system.

No, she says definitively and pushes it aside. But the unflavoured, unsweetened raspberry one almost passes muster. Its OK, she says, eventually. Id add more fruit and a banana, but I could drink that.

Ruby Tandoh, the MasterChef winner who wrote an influential piece earlier this year about the problematic nature of clean eating said that she believes that products like Huel are a result of the anxiety we increasingly have around food. We may want to maximise the health benefits of food, but as she points out, the research is simply not there yet and it denies the mental, emotional and social wellbeing aspects of food, and to absent yourself from that seems like a terrible self-sabotage. Were not robots: food is more than just our fuel.

According to Hearn, all this is to miss the point. The thing that most people have for breakfast is toast and thats optimised for taste. Its not optimised for nutrition. It doesnt provide everything that you need, whereas this does. Were not saying eat this instead of a nice dinner with friends. Were saying have this for breakfast or for lunch if you dont have time to prepare a perfect, balanced meal.

For Blythman, however, its very much an American corporate view of food. The minute I hear the food of the future, I groan. Its something that big venture capitalists get very excited about, like all the failed lab meat that never quite caught on.

Food is about more than food, she says its culture and civilisation and small moments of happiness in otherwise bad days.

Appetite is such a fundamental drive. Its part of what we do every day to make our lives a little bit nicer. Even if your boss is horrible or youve had a bad day, its just that little nice thing you can do for yourself. And these products just dont get that at all.

New food tech from Silicon valley

The Impossible Burger
(Meat-free burger created in a lab)

Vegetarian meat-substitutes have been pioneered by companies like Quorn, using fungi to make equally protein-rich alternatives. As tasty as these are, few would argue that they are indistinguishable from real meat. The American startup Impossible Foods has created a meat-free burger that it claims looks, tastes and even bleeds like real beef. The Impossible Burger contains heme, which is found in animal blood and is largely responsible for the way meat smells and tastes. Artificially produced heme is mixed with plant-based ingredients to create the eco-friendly burger; Impossible Foods says it saves water and farmland and takes 90% less greenhouse gas to produce than beefburgers. Google recently offered $300m for the company but was rejected, remaining as investors. The burger debuted in a New York restaurant last week for $12 and will soon be in supermarkets.

Just Scramble
(Egg-free scrambled eggs)

Egg-free powders, used to replace eggs in vegan recipes, have been gaining popularity, but none can recreate the taste or texture of freshly cooked eggs. Hampton Creek Foods has almost finished developing Just Scramble, the worlds first plant-based substitute for scrambled eggs. Its scientists tested thousands of plants and identified chemical compounds that closely mimicked the properties of chicken eggs. Its chefs used these to create a cholesterol-free yellow liquid that can be cooked in a pan to make a quick and healthy breakfast. The product attracted a large investment from Bill Gates and impressed culinary expert Andrew Zimmern at a tasting: Youre almost there…no wonder youre so excited. The company hopes its animal-friendly egg replacements will reduce the need for battery farming. Just Scramble should be available in shops next year at a price similar to real eggs.

Soylent
(Meal replacement drink)

Soylent, like Huel, is a meal replacement drink intended to meet all the nutritional requirements of an average adult. Rob Rhinehart, an LA software engineer and father of modern liquid meal replacements, first developed the drink in early 2013 as a personal alternative to fast food. Rhineharts blog about the success of his month-long liquid-only diet attracted so much attention that he raised $3m in crowdfunding, which he used to commercialise his creation. Soylent is available in both powder and ready-to-drink forms, the most recent formulae for which upped the proportion of eco-friendly algae to make up a third of the product.

The remainder mostly consists of the carbohydrates found in beetroot and a protein extract from soybeans, along with added vitamins and minerals. Currently, Soylent only ships to the US and Canada and costs $3 per 400-calorie bottle, but sales to other countries are coming soon.

Muufri
(Lab-grown milk)

We already have many plant-based alternatives to cows milk (almond and soy, for example), but none tastes quite like the real thing. However, many dairy cows suffer in poor conditions to produce it. This prompted two students studying in the US to enter and win a $30,000 research competition, funding their work on Muufri, a tasty but humane milk.

In a lab in Cork, Ireland, they transferred DNA from cows into yeast cells to produce the real proteins found in cows milk. The pair then added other natural ingredients of milk such as calcium and potassium, but used a different sugar molecule to make it suitable for the lactose-intolerant. Due to the controversy and suspicion surrounding lab-grown foods, Muufri will only be unveiled when it is believed to be near-perfect. The product is expected to launch late next year, but will initially be twice as expensive as cows milk.

Mealsquares
(Scone-like meal replacement)

If instant and nutritious meals sound appealing, but the idea of drinking them doesnt, a health researchers Silicon Valley startup may have the answer. The flagship product is the Mealsquare, a scone-like creation made from minimally processed, sustainable ingredients such as sunflower seeds, oats and oranges. Each pocket-sized square contains 400 calories and is nutritionally balanced to vitamin and mineral consumption guidelines, helping to combat deficiencies and keep the body healthy. The website recommends Mealsquares as a replacement for one or two meals a day, rather than an exclusive diet, because benefits of certain foods (such as oily fish) cant be included without compromising taste. Currently, the product is available only in the US; a sample 10-pack costs $30 but an $85 subscription buys a monthly delivery of 30. The squares come individually packaged, can be heated up in a minute in the microwave and last for a month in the fridge. Will Latter