“It must have been something I ate” – how many times have you found yourself uttering those words when you’re not feeling your best?

But while this is usually just a throwaway line used to describe a spot of sickness or tiredness, there could be a lot more truth in it than you realise.

Because up to 45 per cent of the UK population is thought to suffer from food intolerance at some time, meaning your diet – however healthy it may be – could potentially cause you problems.