What is a portion?

In the 1960s my dad worked for BP, and a Sunday family treat was to go to the company’s sports club for lunch and a swim. I don’t remember much about the lunch’s main course – I suspect it was some form of roast  - but the cheese and biscuits that followed have left an indelible mark on my memory.

 I have always loved cheese – but this was long before the days of cheese boards heaving with the runny stinky specimens I now expect and eagerly consume. And the club’s cheese plate was not unusual for the time in boasting no more than a couple of Jacob’s crackers and a tiny block of sweaty plastic-wrapped cheddar. You may find something similar in an airline snack pack. I’d like to say the cheese was the size of a matchbox – but that would be too generous. Picture a small box of staples and you may be closer.

Nobody (apart from a complier of airline snack boxes) would offer such a paltry piece of cheese these days - and then ask you to pay for it - but I was surprised to learn last weekend that this is actually the RDA for cheese we should all be aiming for. At least it is the RDA I should be aiming for, as the recommendation is that high fat foods like cheese should be the size of our own thumbs pressed together, and mine are pretty small. This is not enough cheese to fill a sandwich, even if I fold a single slice of bread in half.

Other portion size recommendations include:

. Meat or fish: enough to fit comfortably in the palm of your own hand (around 80-100g).

. Fruit and vegetables: enough to fit in your cupped hands. You should have at least five portions of these a day if you live in the UK, but in Japan the RDA  is 17!

. Carbs: a portion = the size of your fist.

. Oils: the size of your OK sign (finger joining thumb in an O).

This is, of course, just government guideline information. Talk to nutritional scientists and you will find they all have quite different ideas.

Dr Sarah Myhill, for example, recommends a stone age diet in which we eat far more fat than these RDAs suggest. Not just protein, but fat! According to Dr Myhill we should all be cooking in lard, goose and duck fat, and limiting fruit, which are far too sugary.
On her website she says: 'We have been brainwashed into believing that high fat diets result in high cholesterol, which results in arterial disease and therefore premature death. There isn't a shred of evidence to show high fat diet causes high cholesterol and there is a good bio-chemical reason for this. 80% of cholesterol is synthesised in the liver as a result of sugar metabolism. There is no convincing evidence that links high fat diets with high rates of arteriosclerosis'

Her advice makes good sense, and, when I met her last weekend she confirmed that the 5:2 diet is also an excellent way of eating as we were designed to – as stone age man would have feasted and fasted just like this. Dr Myhill uses her dietary advice to treat patients suffering from chronic fatigue syndrome or ME. Find out more about her work here.