The low fat and no cholesterol diet myths

Have you been a follower of the low fat and no cholesterol diet recommendations? Have you reduced your consumption of eggs because of their high cholesterol levels? Do you always buy low fat products but you never check the total energy content? And all in the name of heart health. Well, do I have news for you. It’s all been a con! Or close to.

Our body controls cholesterol levels

Free to eat bacon and eggs again (Photo: Sean Munson)

Free to eat bacon and eggs again (Photo: Sean Munson)

Many of us have been told repeatedly that foods like red meat, eggs and bacon raise our cholesterol levels. An idea we no longer questioned since it had been ingrained in our belief system over a long time. The theory that diets high in cholesterol and saturated fat raise cholesterol blood levels came from studies in animals and humans conducted more than half a century ago. Although the results were rather dubious, persuasive argumentation helped making it a truth and a basis for diet recommendations in many countries. However, more recent results from high quality studies do not support this theory.

It is now clear that we fine-tune our own blood cholesterol levels irrespective of diet intake. The body tightly regulates the amount of cholesterol in the blood by controlling internal production. When we eat less cholesterol, the body makes more, and when we eat more cholesterol the body makes less. As a matter of fact only 25% of the cholesterol in our body comes directly from the diet while 75% is produced by our own liver on demand. Much of the cholesterol that can be found in food can’t even be absorbed by our bodies. So the theory that eating cholesterol will give you a heart attack is clearly a myth for most of us. This is also true for a few hyper-responders in which dietary cholesterol does moderately increase total cholesterol, but not the risk of heart disease.

Low-fat fad

With that out of the way we then come to the low-fat diet. In a way it makes sense to lower fat intake since fat contains about twice as much energy on a food weight basis compared to carbohydrates and proteins. But when food manufacturers lower the fat content they often replace it by sugar to improve the all important taste of their products. If you read the food label you will see that the total energy content is the same or even higher in low-fat compared to conventional products. So there is no real net gain from a weight loss point of view.

But the fat profile might be important. It’s true that some studies have shown that saturated fat intake raises blood cholesterol levels in the short term. This might not be true in the long term and some scientists even claim that the link between saturated fat and heart disease is poorly supported by scientific evidence. There is still too much controversy around this point so it might still be prudent to limit saturated fat intake if not total fat intake. Even though total fat intake varied widely, population and intervention studies have indicated that the risk of atherosclerosis can remain quite low as long as the balance between unsaturated and saturated fatty acids is favourable.  As a matter of fact new Nordic nutrition guidelines just released recommend that consumption of saturated fatty acids should be limited to 10% of total energy intake while monounsaturated fat should be 10-20% and polyunsaturated fat 5-10% of total energy intake.

New focus for diet recommendations

Added sugar in low-fat food the real culprit (Photo: jude)

Added sugar in low-fat food the real culprit (Photo: judy)

The low-fat, high-carbohydrate diet supported by medical authorities for so long might actually be an unintended culprit in the current epidemics of obesity and cardiovascular disease. Studies on low-carbohydrate diets which in turn tend to be higher in total fat suggest that they not only don’t raise blood cholesterol, but have several beneficial effects on cardiovascular disease risk markers. Low-fat diets can even be worse than low carbohydrate diets with the food industry replacing saturated fats with added sugar. There is growing evidence that added sugar may be an independent risk factor for metabolic syndrome which increases the risk of diabetes and should be the focus of new dietary recommendations.

But in reducing carbohydrate consumption do you really need to go for a high fat diet as some proponents suggest? Well, maybe not just yet. It is true that short term you might reduce your weight but long term consequences aren’t yet all that clear particularly if you include a lot of saturated fat in the diet. It will take some effort for me to drop the entrenched view that saturated fat is bad for you.

Confused by the conflicting science? Stick to the balanced diet concept and plenty of exercise and you will not go wrong.


4 thoughts on “The low fat and no cholesterol diet myths

  1. Det är svårt att läsa det du skriver (och det vill jag verkligen kunna göra), eftersom det är så låg kontrast mellan den ljusgrå texten och den vita bakgrunden. Mina ögon är inte längre vad de var 🙂 Skulle du kunna tänka dig att ha svarta bokstäver istället? Please…

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