Sunday, 22 February 2009

Lies, damned lies and surveys

If you watch the current TV ad on saturated fat from the Food Standards Agency, eight seconds in the source details appear on screen. It reads "NDNS 2000/1", and probably means nothing to most people. It meant nothing to me until a few days ago when I was writing about The National Diet & Nutrition Survey: adults aged 19 to 64 years - 2000-2001. Yes, the TV ad's information comes from the flawed survey I mentioned in my blog.

So, how was the information collected for the survey/s? OK, I'm simplifying it a bit, but this is the general idea.

Individual foods were weighed in a comprehensive, and complicated, way by participants, and entered into a food diary. For instance, ordering steak and kidney pudding and chips, with mushy peas, in a small café would necessitate splitting everything into their constituent parts, in reality or statistically. The weight of the two meats, the ingredients of the suet pastry, the ingredients of the gravy, the quantity of peas and size of the chips would all have to be estimated and entered. This was then coded by the field worker in charge of that sector.

Once everything is coded and churned through a computer a few times, out pops a warning to the people of the United Kingdom. It’s unlikely to be

“Steak and kidney pudding, chips and mushy peas isn't a good choice for dinner every day”.

Oh no, given the level of advice trumpeted so far it’s much more likely to be



It doesn’t matter how much the scientists break down the constituent parts of foods, then analyse the results, the advice is going to be totally meaningless, unless they do proper trials and specifically include participants who eat real food, and are careful about their carbohydrate intake.

I'm no expert, but I'm not the only one who thinks that the methodology that has been used in these surveys is, well, crap!

The Scientific Advisory Committee on Nutrition, which advises the Department of Health, wrote the following in The Nutritional Wellbeing of the British Population 2008.

“Consumption figures include non-meat components of meat-based dishes, so
figures for consumption of redand processed meat and meat-based dishes are not
directly comparable with recommendations for red andprocessed meat. Detailed
recipe analysis of composite processed products would be required to
calculatered and processed meat content alone
. “

Exactly! Why did nobody notice that before now?

However, the committe's concerns about the methodology doesn't prevent it from making the following claim:

"Mean intake of red and processed meat and meat based dishes has decreased since 1986/7 "
1986/7 - men 155g/d : women 96g/day
2000/1- men 138g/day : women 79g/day

Great! Well, we are told that red meat and its products cause bowel cancer, and our intake of red meat and its products has decreased, so that must mean that bowel cancer figures are down as well then.

Unfortunately the answer is no.

"In Great Britain male bowel cancer incidence rates rose slowly by an average of
1% each year between 1979 and 1999, since when there has been a slight decrease. Over the same period the female rates have changed very little."

As if the surveys were not flawed enough already, the Nutritional Wellbeing of the British Population decided that the latest survey pobably contained under-reporting by as much as 25% on some food types ... although they don’t know exactly which ones ... or by how much.

Nor do they know if there had been under-reporting in the 1967/8 survey either... but it doesn’t stop them using it as a basis for the LIPGENE project all across Europe!

Ah yes, the LIPGENE project!

This Europe-wide study sets out to test, “in controlled human intervention trials”, a hypothesis that dietary fat causes the metabolic syndrome that affects 10-20% of the population. The syndrome is thought to increases the risk of type 2 diabetes mellitus 2.8 to 8-fold and cardiovascular disease 1.5 to 6-fold.

The idea was to devise four diets that could be used in eight countries across Europe, as follows:

Diet A: 16% saturated fats; 12% mono-unsaturated fats and 6% polyunsaturates –38% of total calories
Diet B: 8% saturated fats, 20% mono-unsaturated fats and 6% polyunsaturates – 38% of total calories
Diets C & D: 8% saturated fats, 11% mono-unsaturated fats and 6% polyunsaturates – 28% of total calories
Diet D supplemented with a 1.24g polyunsaturated fatty acid capsule, with a placebo for Diet C .

Now, this is all very laudable, but ... and it’s a very big but!

The basic model diet removed the "added fats" from “the average UK diet” – "spreads and oils, milk, cheese, biscuits, cakes, buns and pastries". So it removes the good fat - saturated animal fat - along with the junk food!

These were then replaced by "spreads, cooking oils, mayonnaise, baking fats and biscuits" provided by Unilever Bestfoods (Netherlands), (now Unilever Bestfoods UK Ltd).

Unilever produces delicacies such as Flora spread and Stork margarine, both made from vegetable oils, and Hellman’s Mayonnaise which, despite being labelled ‘Real’ is actually made from soybean oil...

No mention is made of a replacement for milk, but as Unilever now make a Flora Pro.Activ semi-skimmed milk drink, it would be a fair assumption that this was used in the diets.

So what’s wrong with all this? Let’s look first at the “the average UK diet”. This is none other than our old friend the National Diet and Nurition Survey of UK adults from 2000-1, with just 1724 participants – 833 men and 891 women – a smaller sample than the previous one by about a third.

Just 1724 people out of a total population of approximately 60 million - less than the population of the UK's smallest city, St David's. That’s one two-hundredth of one percent of the UK population - who had to be house-owners, incidentally - and that is the basis for all the Government’s nutritional campaigns, and for the European LIPGENE project!

We could do with a lot more common sense and far fewer 'experts', but it's unlikely to happen. I'll just keep on eating what I know to be a healthy, low-carb diet, complete with saturated fat, thank you.

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