Nutrition: the facts about fats
Entire books have been written about dietary fats, but the truth is that while few of us need to know the intricacies, we should know the basics. So here are some brief facts about the fats in food:
Some nutrients, such as vitamins A, D, E, K and carotenoids (antioxidants found in some fresh fruits and vegetables), require a little fat for absorption and so a drizzle of olive oil on a salad or vegetables, or a few seeds sprinkled on a fresh fruit is advisable.
Omega 3 fats are perhaps the best known of the beneficial fats, found mostly in oily fish, walnuts, linseeds, soybeans/tofu and purslane. They help reduce blood pressure, alleviate inflammation, balance blood glucose, combat dry skin and may influence mood.
Saturated fat, of which there are several types, is typified by the white fat you see on the underside of poultry skin, or marbled through red meat. We can use very small amounts of saturated fats, but excess can encourage raised cholesterol. Perversely, one saturated fat, stearic acid, can lower cholesterol and you may be pleased to learn that it is found in chocolate. But a high-sugar content can negate the benefits, so go for very dark chocolate. In general however, saturated fats should be avoided.
Trans-fats are generally created in a laboratory and are solid at room temperature, thus useful to the food industry. They are mostly used in cakes, biscuits, confectionery, puddings and pizza, and are also popular with fast food restaurants as they are cheap and long-lasting. Also called hydrogenated (or partially hydrogenated) vegetable oil or vegetable shortening, trans fats can raise LDL (the bad cholesterol) while lowering HDL (the good type) as well as block absorption of good fats. Avoid in all forms.
All fats contain nine calories per gram, so be aware of the amount of fat you are eating, even if it’s the good type.
Simple signs that suggest you may be lacking in essential fats are dry skin, constipation, poor wound healing, frequent infections, inflammation of joints and small bumps on the back of the upper arm.
Ian Marber is one of the UK’s most highly regarded nutrition experts and the author of 11 books. Visit ianmarber.com