I am talking, of course, about Ancel Keys. Don’t know who he is? He was regarded as the “father of dietary science”. His work has had a major influence on the world’s eating regime since the 1950s. I first became aware of Ancel Keys when reading Gary Taubes book "Good Calories Bad Calories". Taubes is a science writer/journalist who examines every scientific study objectively and debunks many of the myths surrounding current day nutritional recommendations. If you’re up for the challenge (it’s quite heavy and scientific) it is the most amazing read!
I’m going to go off tangent for a moment before I discuss the work of Mr Keys, so bear with me. I’m sure most of you remember doing science experiments at school. I was by no means an A+ student, but there were certain basic elements that stuck with me. One was to do with hypothesising. You wrote a hypothesis that could be tested and then set out to prove or disprove it. Generally, you didn’t go in with a pre-conceived idea of what you wanted the results to be, or there was a risk that your results could be biased and become skewed. I certainly wouldn’t have been given very good marks if I had tipped the results one way or the other. And for his “Seven Countries Study”, Ancel Keys gets an F from me!
Keys set out to track the fat consumption and heart disease levels of various countries throughout the world. His hypothesis was that fat consumption causes heart disease. His results were ‘conclusive’. Seven countries saw their levels of heart disease increase in correspondence with their levels of fat intake. Here’s the original evidence that Keys presented:-
From looking at the above graph, it is quite obvious that his hypothesis can be reasonably confirmed. But here is where the issue lies. Keys omitted some important information from his original study. Although named the “Seven Countries Study”, Keys actually had data from twenty two countries! Why then, you ask, isn’t the information for all twenty two countries shown in his evidence? Because that information blasts his hypothesis to pieces! Take a look at the graph which plots the results of ALL countries (courtesy of Hyperlipid):-
A bit different isn’t it?!? No respectable scientist could reasonably infer from these results that his hypothesis was completely confirmed. Sure, there might be a slight correlation, but there is certainly not enough evidence to prove it beyond a shadow of a doubt. Peter at Hyperlipid has also added in another couple of dots to his graph to plot some countries with traditionally high fat diets (the Masai, the Inuit, the Rendile and the Tokelau), countries that Keys conveniently ignored in his study:-
The further issue with a study like this is that when specifically testing one element of the diet, every other element is ignored. Another reason for the Fail mark! A basic understanding of a scientific experiment is that you need to control the other variables. Therefore, every country needed to be eating exactly the same amounts of protein and carbohydrates, basically exactly the same diet, apart from the fat intake. That was the only way to really confirm the hypothesis, otherwise there’s just too many variables!
Notice that all of the countries included in Keys “Seven Countries Study” are highly developed, Western nations. How do we know what other factors could have contributed to high heart disease rates? I would hazard a guess that you could produce the same, if not more convincing results, measuring the sugar/refined/processed grains consumption of these countries. It's always amazing how statistics can be twisted to produce whatever result is desired by the author.
And so, the final piece of the puzzle that Keys drew out of this study was that it is saturated fat that is the bad guy. Bring on the Times Magazine front cover, and adulation the world over, and Keys becoming the “it” man. Saturated fat was off the menu. The low-fat, high carbohydrate diet craze was here to stay!
Apologies for the highly scientific post! I’ve tried to make it as easy to understand as possible. I’m just hoping that people can start to question why they eat a low fat diet. Is it because you truly understand the science behind it? Is it simply because you relate to the notion “fat will make you fat”? Or is it because you’ve had it rammed down your throat since birth? I’ve been there! I’ve knowingly consumed countless tubs of low-fat yoghurt, faithfully poured no-fat milk on my morning cereal, and meticulously cut off every piece of visible fat from a piece of meat. But as you know, it didn't work for me! The challenge, therefore, has been to refocus my thinking. To accept that conventional wisdom is wrong. To not feel guilty when I hoe into that beautiful chicken breast with the skin on... And I encourage you to do the same!
Further reading:- Mark talks about saturated fat, and fats in general.
ps – please keep in mind that you need to consider your other dietary choices as well. I have done amazingly well on a higher healthy fats diet because I’ve have abolished my sugar intake and kept my carb intake to fruits and vegetables only. If you simply start eating high fat food but don’t change any other areas of your diet, you will get fat and sick.