Ever since the 1950’s, people in the West were taught that dietary fat should be avoided, since it leads to obesity. New research, however, shows a totally different picture: “good” fats not only don’t make you gain weight – they are essential to your health!
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Essential building material
The idea that dietary fat is somehow bad for you has given rise to one of the most popular fad diets – the low-fat diet, which excludes oil, butter, cheese, etc. Like most fad diets, however, it ignores an important fact – you cannot live without fats. Our cell membranes are built of fat, and so are our blood vessel walls and the protective covering of the brain. What’s more, some of the essential vitamins – A, E, D, and K – are fat-soluble, meaning that we cannot absorb them unless we consume fat .
It’s true that fat contains a lot of calories – 9 per gram as opposed to just 4 in a gram of carbs. But the desire to avoid those extra calories has led to very sad consequences in the West.
The zero-fat obsession
Starting in the 1980’s, the U.S. authorities published guidelines advising to avoid high-fat foods. The food industry reacted by creating low-fat and zero-fat products, from yogurt to cookies. The issue is that fatty usually means tasty; to avoid blandness, sugar was usually added – lots of sugar. As a result, obesity and prevalence of heart disease in the West rose instead of falling.
Saturated vs. unsaturated
While refined carbs are definitely worse for both your body shape and heart than fats, not all fats are created equal. Natural fats are divided into unsaturated (which remain liquid at room temperature) and saturated (solid at room temperature). The general scientific agreement is that unsaturated fats are very good for you. They form two groups:
- Monounsaturated – found in olive and sunflower oil, nuts and seeds, avocados, etc.; their intake is linked to lower risk of mortality;
- Polyunsaturated – essential fatty acids omega-3 and omega-6; found in fatty fish (like salmon and sardines), flaxseed and soybean oil, walnuts, etc. These fats are called essential because our body cannot produce them; they are necessary for our brain, liver, skin, and more.
What about saturated fats? Scientific opinions are divided. Most official guidelines recommend to consume less saturated fat (mean, cheese, butter), but many large recent studies show no link between these fats and heart disease. It is true, though, that the risk of heart disease decreases if you partly replace saturated with unsaturated fats (for example, using olive oil instead of butter and lard or putting avocado on your sandwich instead of mayonnaise).
Trans fats are bad
Trans fats are made artificially by adding hydrogen to vegetable oils in order to make them solid (often they appear on the label as “partially hydrogenated oils”). Scientists agree that trans fats are very bad for your health: they increase the “bad” cholesterol and the risk of cardiovascular disease (see this study, for example). Trans fats are found in fried foods, pies, ice cream, cookies, etc.
As you see, eating fats does not increase your risk of obesity – sugar does. Make sure to add olive oil, fatty fish, and nuts to your diet, avoid processed foods and reduce your intake of refined carbs. And remember: maintaining a healthy weight requires exercise, not just diet.