The truth about low-fat foods
For years now those of us watching our weight, managing our cholesterol levels or eating for a healthy heart have opted for the low-fat option. But are these low-fat foods really as good for us as we originally thought? Nutritionist Kerry Torrens investigates...
Take a walk down any aisle in your local supermarket and you'll see fat-free desserts, low-fat biscuits and calorie-counted ready meals. But while our shopping baskets are full to bursting with these guilt-free foods our waist-lines keep getting bigger.
Enter the trans-fats
Since the 1980s there's been a boom in low-fat products as the message got out that to improve our health, especially heart health, we needed to reduce the amount of saturated fat in our diets. This means cutting back on full fat dairy foods, red meat and certain processed foods. It's true that fat supplies more than twice the calories per gram of carbohydrates, and saturated fat is the type of fat primarily responsible for clogging our arteries and increasing cholesterol levels. But, as we came to terms with this unpalatable fact, the food industry got to work replacing the animal fats in their products with un-saturated vegetable oils. Some of the changes they had to make included altering the structure of the vegetable oil so it could be used in the place of solid fats. To do this the food producers used a process called hydrogenation which created a solid or semi-solid fat thought to be more appropriate for their food processing needs.
Unfortunately, we now know these hydrogenated fats increase levels of dangerous trans-fats which are both bad for the heart and our cholesterol. Although trans-fats can be found at low levels in some natural foods these man-made versions meant it was likely we were eating more of them. Since learning of the dangers of trans-fats the food industry and our UK supermarkets have been working hard to reduce levels of them in their products.
As well as altering the oils used for producing low-fat foods, manufacturers also found they had to increase the amount of sugar in their products so we continued to enjoy their taste and texture. All of this meant that the typical low-fat product tended to be high in carbs, might contain trans-fats and at the end of the day had a very similar calorie count to the original product. In fact when we eat foods high in carbs especially white refined ones, our bodies digest them more quickly. This can lead to blood sugar swings and cravings making it more difficult to control our overall calorie intake - which means that second or third 'low fat' biscuit starts to look very tempting! A diet too high in these refined carbs and sugars can be as unhealthy as a high-fat diet because it increases the risk of diabetes, heart disease and causes high cholesterol levels.
Good fats and bad fats
We all need some fat in our diet, not least because it makes our food more palatable and tasty. Nutritionally, fats do more than simply supply calories. Certain fats, like those in nuts, seeds and oily varieties of fish provide essential fatty acids (including the omega-3 variety). These essential fats are important for maintaining healthy blood vessels, making hormones and for the correct functioning of our nervous system. The fat in our diet also helps us absorb certain vitamins, the fat-soluble ones, which include A, D, E and K. Following a very low-fat diet makes you more likely to be low in these vitamins and that can impact your immunity, limit the body's ability to heal itself and have an influence on bone health. It's better to focus your diet on the healthier unsaturated fats by including more fish, nuts, seeds and vegetable oils including avocado and olive and reduce your intake of saturated fats. Here's how to make your meals naturally fat-healthy...
Minimise the saturated fat in your diet by:
- Replacing fats like butter and lard with un-saturated oils like rapeseed or olive oil.
- Eating more fish, nuts and seeds - for example choose salmon instead of bacon for a weekend brunch; snack on unsalted nuts rather than crisps.
- Removing the skin from poultry and trimming visible fat from other cuts of meat.
- Checking labels on food products - see tip box.
- Using good quality un-saturated oils, like walnut or pumpkin, for dipping your bread instead of using spreads.
- Avoid frying instead steam, bake, poach or grill.
- Replace mayo with plain yogurt - just add a squeeze of lemon juice and some mixed herbs, chives work well.
- Make chips by baking chunky cut potato wedges with a drizzle of rapeseed oil and a sprinkle of paprika.
Suggested low-fat recipes:
Kerry Torrens is BBC Good Food magazine's nutritional therapist.