There is certainly a cacophony of nutritional and food advice being spewed forth today. But far from cutting through the proverbial, two recent books simply add to the noise.

Pity the poor ethical, health-conscious foodie. These angst-ridden souls must stand in the supermarket (if they couldn’t make it to the farmer’s market) and feel like dropping to their knees. How, they wail, to find food that is good for the environment, won’t make you fat, won’t poison you with pesticides, is affordable, won’t take five hours to cook, doesn’t exploit small farmers in the developing world and still actually tastes good? It’s a regular nightmare. If only there were right-minded food gurus out there to help them escape this culinary conundrum.

Thankfully, two leading food writers have stepped up to the plate. US food journalist Michael Pollan’s slim guide, Food Rules, was first published a couple of years ago, but has recently been re-released in an illustrated version. Joanna Blythman has now joined in with her own weightier effort – part-guidelines, part-reference book – called What to Eat. While both books have some merit, they are also stuffed full of the prejudices of those who love and fear food in equal measure.

Pollan recognises the difficulties early on: ‘Eating in our time has gotten complicated – needlessly so, in my opinion… Most of us have come to rely on experts of one kind or another to tell us how to eat – doctors and diet books, media accounts of the latest findings in nutritional science, government advisories and food pyramids, the proliferating health claims on food packages. We may not always heed these experts’ advice, but their voices are in our heads every time we order from a menu or wheel down the aisle in the supermarket.’ Presumably, Pollan aims to join in the mental cacophony.

This point about food dilemmas is echoed by Blythman, who recounts a conversation with her friend who was finding it hard to balance her tight finances. This made it difficult to afford the ‘more ethical, progressive food’ she aspired to, while her busy life meant that by the time she’d got home from the gym, the only shop open was a small branch of a major supermarket chain. ‘Food’, she bemoaned, ‘has just got so complicated’.

Trouble is that our gurus aren’t necessarily making the problem any easier. Blythman offers 20 ‘food principles’ at the start of her book, each with a few paragraphs of explanation; Pollan suggests 64 food ‘rules’, though the last one is ‘break the rules once in a while’. Hey, live a little. In fairness, Pollan’s book aims merely to provide a simple elaboration of the motto from his earlier book, In Defence of Food: ‘Eat food. Mostly plants. Not too much.’ (See a review here.) But elaborating seven-word mottos soon gets, well, complicated.

There are some clear themes that span the two books, however. Both Pollan and Blythman emphasise the need to eat ‘real food’. Blythman equates ‘real’ with ‘natural’: ‘Nature is a very clever, intricate system and natural foods in their whole, unprocessed form have an intrinsic nutritional integrity. We know this because humans have been eating them for centuries.’ About the last thing you can claim about any of the things we eat - apart perhaps from those things we capture in the wild, like fish - is that they are ‘natural’. Anything that is the product of agriculture is also the product of thousands of years of selection and tinkering to create crops that are just right in terms of production, nutrition and taste.

For Pollan, the emphasis is more on tradition and food culture. So rule #1 is ‘Eat food’ (as opposed to what he calls ‘edible foodlike substances’). The point is clearer with rule #2: ‘Don’t eat anything your great-grandmother wouldn’t recognise as food.’ (He adds that if your great-grandmother was a terrible cook, pick someone else’s great-grandmother, preferably French or Sicilian.)

Now, there are many valuable things to be learned from our accumulated knowledge about food. To make an analogy with music: Beethoven and Mozart are both great composers, and anyone with any interest in musical form and structure could benefit enormously from listening to and even playing for themselves such beautiful music. But if we stopped listening to anything from later than our great-grandmothers’ era, we would miss out on the much slighter but equally enjoyable music of The Beatles and many other artists. To take Pollan’s attitude and to refuse the idea of novelty is just unnecessarily conservative. If you enjoy the flavour of extruded cheese strips or some such, and they contain some useful nutrition, then why not enjoy them?

This has little to do with the substance of food and everything to do with a revulsion towards the modern world. Hence, rule #19 – ‘If it came from a plant, eat it; if it was made in a plant, don’t’ – reveals a perverse anti-industrial prejudice. In fact, he refers to the collaboration between food policy and big food companies as the Nutritional Industrial Complex. Most of the things we buy in supermarkets went through some kind of processing plant at some point in their journey to our plates.

A similar snobbery is exhibited in rule #20: ‘It’s not food if it came through the window of your car.’ On this point, the old quotation from the Roman playwright Terence, Homo sum, humani nihil a me alienum puto (‘I am a man, I consider nothing human alien to me’) seems apposite. While it is undoubtedly true that there are many rewards in learning about the foods of the world and in rediscovering our own local food traditions, there are also times when a Big Mac absolutely hits the spot. If Pollan doesn’t get that, maybe he’s not fully embracing his humanity.

Blythman’s second principle, ‘see the value of cooking’, also points to the life-enhancing quality of being able to rustle up something tasty. Indeed, Blythman has a variety of suggestions about how to prepare quick and unfussy meals for each of the different food groups she goes through. I will definitely be trying her suggestion to cover unfashionable cuts of white fish in lemon juice, double cream and Parmesan then quickly grilling them. This celebration of cooking is mirrored in Pollan’s book in places like rule #39, ‘Eat as much junk food as you like, as long as you cook it yourself’. Weirdly, Pollan thinks if we had to make junk food ourselves, we would only do it rarely. Maybe he’s never heard of electric deep-fat fryers, oven chips and microwave pizzas.

But Blythman and Pollan should also see the value in not cooking. One of the joys of modern life is that we now have the choice. So for all those millions of housewives for whom cooking every day was a thankless chore delivering unappetising results, the option to bung something in the microwave or get a takeaway is a real blessing. Most people I know will vary between eating convenience food and home-cooked meals according to time, cost, mood and so on, in ways that can’t be simply reduced to a collection of rules. That seems a lot more sophisticated than saying ‘home-cooked, good; convenience, bad’.

Both Blythman and Pollan are sceptical about some claims made in the name of nutritional science. For example, as Blythman rightly points out, the decades-long war on saturated fat is coming to a close as it becomes increasingly obvious that fat is not the cause of heart disease. Pollan ridicules the endless search for the element in our diets that explains our Western pattern of chronic diseases or the hunt for some specific food or other to be a panacea for all ills. He isn’t anti-science, he says, but we should accept that nutrition is a pretty young science.

Yet both writers can’t help themselves when it comes to finding scientific backing for their pet prejudices. So Blythman promotes various foods based on health claims made about omega-3 fatty acids and antioxidant polyphenols (and some wackier claims based on traditional Ayurvedic medicine, too).

In Pollan’s book, rule #25 suggests ‘Eat your colours’. Why? ‘The colours of many vegetables reflect the different antioxidant phytochemicals they contain - anthocyanins, polyphenols, flavonoids, carotenoids. Many of these chemicals help protect against chronic diseases, but each in a slightly different way, so the best protection comes from a diet containing as many different phytochemicals as possible.’ That’s an awfully grand statement from someone who earlier asserts that ‘It’s gotten to the point where we don’t see foods anymore but instead look right through them to the nutrients (good and bad) they contain’.

These micronutrients may turn out to be beneficial to our health, though frankly any such hypothesis would be very difficult to test. Already, claims about the benefits of fish-oil supplements (and the omega-3 fats they contain in abundance) have been called into question. Pollan and Blythman, having rightly suggested scepticism about health claims made for foods, are both guilty of a bit of cherry-picking when it suits them.

They also have a blind spot for the role of the state. All that dubious nutritional advice is the fault of big food corporations conspiring to twist official guidance to suit whatever products they are flogging. While big companies do, of course, lobby government, the drive to micromanage our diets has really come from the medical profession and politicians in cahoots with the kind of food campaigners Pollan and Blythman would laud. It wasn’t Big Food that told us to avoid fat, eat more fibre and get our five-a-day fruit and veg. Those ideas became common sense because they were all driven from the top.

Beyond a few quirky tips and handy recipes, Pollan and Blythman fail in offering a useful guide for our edible existence. Instead, they simply expose their own prejudices and those of the audience they are writing for. That’s without even mentioning their pro-local, pro-organic, eat-less-meat-to-save-the-planet beliefs, which only tend to demonstrate their anti-modern outlooks. Blythman writes that readers shouldn’t ‘fall for the line that organic food is just a trendy lifestyle choice for the neurotic rich. There’s nothing new or modish about organics.’ That’s very true. Like the poor, the neurotic rich are always with us.

As long as we get enough to eat – that is, we don’t go around feeling hungry – and get some modicum of variety in what we eat, there really isn’t much more to say. If you want to be a gourmand, that’s as good a source of interest and pleasure as anything else you could do. If you’re happy to munch ‘junk’ for ever more, it’s still highly likely you’ll live long enough to qualify for the pensioner’s special at your local cafe.

If there’s one rule that’s worth following about food, it is this: stop obsessing about what to eat.

Lessons from the new food priesthood, spiked