Food exclusion: a dangerous game

I keep coming across people – in person, on chat forums, word-of-mouth friends of friends – who are excluding foods from their diets experimentally.

Some seem to be just having a go to see whether they feel better, perhaps because they’ve read an article.

Others have visited medically untrained complementary therapists or taken unvalidated food intolerance tests, and are acting upon their recommendations. Perhaps they have friends who say ‘it worked for me’ – as if the testimony of a pal somehow overrides the considered scientific analysis of the international medical community.

And so they start to eliminate. They’re quite clued up. Wheat/gluten and dairy are the big two. They read labels, know rye and barley have gluten too, realise that ‘lactose’ denotes dairy, understand that both can turn up in surprising places, like stock cubes, chewing gum, medicines, soy sauce, charcuterie, as well as obvious ones, like cakes, biscuits.

And what happens? They often feel better. Their conclusion? Typically: “I was feeling ill when I was eating gluten and/or dairy. I feel fine when I’m not eating gluten and/or dairy. Therefore I am intolerant to gluten and/or dairy.”

Possibly, but not necessarily – and, arguably, probably not. Cut out gluten and dairy and you’re constrained to cut out all the junk food in which these two foods happen to be found – doughnuts, hot dogs, burgers, the rest. You’re also compelled to consume, inevitably, more vegetables, and alternative treats to fill the gap – fruits, dried fruit, nuts, dark chocolate. Often, it is the inclusion of these wholesome foods – not the exclusion of the unhealthy ones – which is the main reason for improved health. Your diet just got better. A change is good as a rest. But how many draw those conclusions? Very few, if any.

You may be thinking – So what? As long as I feel better, does it matter?

It matters because you could be unnecessarily avoiding healthy gluten-containing and dairy foods – pumpernickel bread, pure wholewheat cereal, natural yoghurts, for instance – which contribute important nutrients.

It also matters because you could be failing to properly uncover a genuine problem with food. One such could be coeliac disease (CD), an illness about which I’m currently writing a new book. CD is a serious autoimmune disorder, triggered by gluten, which effects 1% of us, and is largely undiagnosed among the population. Alternative tests cannot diagnose CD. We have proper tests which can. Trouble is, if you stop eating gluten before you’re tested with these proper tests – then the proper tests may not work.

It matters furthermore because you could be affecting the way your digestive system works. Stop eating dairy and your body begins to scale down its production of lactase – an enzyme needed to digest lactose (milk sugar). Try to eat dairy again after some months’ unnecessary avoidance and you may get tummy upsets – typical symptoms of lactose intolerance, caused by reduced lactase levels. This may convince you that the original test was right – you *were* dairy intolerant after all – and that you should avoid it. Again, possible – but probably more likely is that you never had a problem with it to start with, and if you started to eat it again gradually, you could train your body to retolerate it. Many people don’t do that, dietitians have told me, and osteoporosis in later life is their occasional reward.

Just three examples of why casual, “oh it’s worth a go” food exclusion may not be worth a go at all.


  1. Sarah

    Interesting debate. You raise a good point about the body's production of lactase. However I think we should give people a bit more credit – that if they're cutting out gluten and dairy this doesnt necessarily mean they're missing out on important nutrients – they may well be careful to balance their diet and make sure they are getting vital nutrients from other sources, for example probiotic supplements as opposed to having bio yoghurts.

    Also I dont think this appreciates that some people do cut out foods and genuinely feel an awful lot better for it!

  2. Alex G

    Thanks for commenting.

    I make it clear in the post that these are possibilities, and of course it won't apply to everybody. Some people are indeed very clued up about nutrition. But I’ve spoken to enough dietitians to know that it happens a lot.

    Probiotics, incidentally, are not nutrients, and I absolutely do acknowledge that people feel a lot better for excluding certain foods – it's one of the key thrusts of my post to clarify that the reason for this may well not be the one they assume – so I don't really understand your last line.

    Thanks again.

  3. Anonymous

    Sadly, I find that if you go to several GP's, gastro consultants, dieticians and fail a dairy scratch test and initial blood test for coeliacs they then tell you to go away and stop wasting their time. They leave you to have to work out these things alone, with the aid of the internet and in the meantime the only way to operate in normal, daily life is to exclude the things making you ill every day as best you can. If GPs took this seriously it would help a great deal, but even hospital consultants can be a bit lacking without a quick, easy diagnosis.

  4. Pingback: Esther Rantzen’s flawed gluten ‘proof’ | Allergy Insight

  5. Pingback: The Lottery of Food Sensitivity Testing | Allergy Insight

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

By continuing to use the site, you agree to the use of cookies. Please read our Privacy Policy and our Affiliates Disclosure in 'About' more information

The cookie settings on this website are set to "allow cookies" to give you the best browsing experience possible. If you continue to use this website without changing your cookie settings or you click "Accept" below then you are consenting to this.