For many people, following a low fat diet is a way of keeping weight down, managing cholesterol levels and eating for a healthy heart. Recent studies however, now suggest that low-fat foods are not as good for us as originally thought.
Over the last 30 or so years, there has been a massive increase in low-fat products, introduced in an attempt 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.
Fat provides more than twice the calories per gram of carbohydrates and saturated fat is the type of fat primarily responsible for clogging arteries and increasing cholesterol levels. As this has become a widely accepted fact, the food industry has gradually worked to replace animal fats in their products with un-saturated vegetable oils.
Some of the changes have involved altering the structure of the vegetable oil so it can be used in the place of solid fats through a process called hydrogenation. Hydrogenation changes the structure of the oil through heating and processing with hydrogen gas that changes the molecular structure of the oil, so that it behaves like saturated fat. This makes the fat harder and solid at room temperature.
This solidity is desirable for food manufacturers, as it adds substance and body to the product, whilst lengthening the shelf life of food products. Through hydrogenation, all traces of essential fatty acids are destroyed and hydrogenated fats take their place.
It is now known that these hydrogenated fats increase levels of dangerous trans-fats, which are both bad for the heart and cholesterol. Since the dangers of hydrogenation and trans-fats have been accepted, the food industry (particularly in the UK) and some supermarkets have been working to reduce levels of them in their products, with some going so far as to remove all of the trans-fats from their products.
As a consequence of altering the oils used in producing low-fat foods, manufacturers have now discovered the need to increase the amount of sugar they put in their products so that taste and texture is maintained. Without doing this, their food would taste very bland. As a consequence, this has meant that the typical low-fat product is high in carbohydrates and may contain high levels of trans-fats, which often have a very similar calorie level to the original product.
To make matters worse, when we eat foods high in carbohydrates especially the white refined variety, our bodies digest them more quickly. This can lead to undesirable swings in blood sugar levels and cravings, making it more difficult to control our overall calorie intake.
Finally, a diet too high in refined carbohydrates and sugars can be as unhealthy as a high-fat diet, because it increases the risk of diabetes, heart disease and leads to high cholesterol levels.