The fight against fat: how to identify good from bad
We all need fat, I’m glad to say. It’s essential for the absorption of vitamins A, D, E and K, and where we find essential fatty acids like omega-3s. We also need fat for a multitude of other functions such as building cell walls and muscle movement.
But fat is the most calorie-dense food we can eat, and most dieticians agree that if you’re trying to lose weight while maintaining a balanced diet it’s necessary to limit your fat consumption. It’s especially important to watch the amount of saturated and “trans” fats (usually listed as “partially hydrogenated oil” and used in solid margarine, biscuits, cakes and fried food) as they raise our “bad” LDL cholesterol, which is linked to heart disease. And yes, we all know someone who swears by a high-fat keto diet – but the vast majority of health professionals dismiss these as at best not a long-term solution and at worst downright dangerous.
Unsaturated fat is liquid at room temperature and includes polyunsaturated and monounsaturated oils. Sunflower oil and rapeseed oil are high in polyunsaturated fat, as is oily fish. Omega-3 and omega-6 fatty acids are found in polyunsaturated oil, and a balance of the two is essential for good health, although most Westerners get too much omega-6 (found in cooking oils) and not enough omega-3 (found in algae and oily fish). Monounsaturated fats (in olive oil, nuts and flaxseed), are central to the Mediterranean diet, which is linked to low rates of heart disease.
Saturated fat (generally a solid) is found in high levels in meat as well as butter, cheese and coconut oil. It’s not bad in itself, but most doctors agree that too much saturated fat tips the balance of cholesterol in our blood from “good” high-density lipoprotein (HDL) to the “bad” low-density lipoprotein (LDL); we should limit intake to less than 10 per cent of our daily calories – an 8oz steak or a couple of matchboxes of cheese, but not both.
Trans fat, meanwhile, is the baddie of the fat world. A small amount occurs naturally in meat and dairy, but almost all of it is manufactured by combining hydrogen and vegetable oil to make a solid, or “partially hydrogenated” fat. These are cheap and improve the shelf life of foods but are also linked to heart attacks, strokes and type 2 diabetes. The World Health Organisation has labelled them “toxic” and is campaigning to remove trans fats from the global food chain by 2023. They’re banned in Denmark, Austria, Iceland and parts of the US, but the UK relies on voluntary reduction by manufacturers. Why? It’s a very good question and seems a bizarre approach since it would require food companies to choose to reduce their profits. How to spot trans fats? Look for “partially hydrogenated oil” on the label.
‘Healthy’ labels: what do their claims really mean?
Fat-free ⇢ Contains less than 0.5g fat per serving, but ask yourself what is replacing the fat to make it taste and feel similar to a full-fat product? It’s probably either sugar or refined carbohydrate, both of which are implicated in obesity. Or it may be a gel-type thickener such as carrageenan – a seaweed extract that may cause gut problems, particularly for people with Crohn’s disease.
Low fat ⇢ Has 3g or less of fat per 100g. It may also contain additives to compensate for the reduction in fat.
Sugar-free ⇢ Has less than 0.5g per serving of free sugar or intrinsic sugar, but will probably have artificial sweeteners and flavouring as it can’t (for example) contain any milk or whole fruit as that would contain intrinsic sugar. May also have added thickeners to give it a better “mouth feel”.
Low sugar ⇢ Less than 5g of sugar per 100g. Low-sugar products like baked beans and ketchup have artificial sweeteners added.
No added sugar ⇢ No “free” sugar is added, but there may be naturally occurring “intrinsic” sugar in the food.
Reduced fat or sugar ⇢ Contains at least 30 per cent less fat or sugar than the standard version of the product. Not necessarily healthier, however, and may have almost as many calories along with extra additives.
High in protein ⇢ Legally, a product can claim it is high in protein if at least 20 per cent of the calories in the food are provided by protein, which has four calories per gram. But that doesn’t mean it’s as high a source as alternatives. So a vegan pork substitute can claim to be high in protein with 12.5g protein per 100g, but it is still much less than the 30g in the lean pork mince it mimics.
