The new formula for food companies was to take out fat and add masses of sugars to make products more palatable. Fat-free cakes, yoghurts and cereals hit our shelves, while butter gave way to low fat margarine. Sausages and steak were replaced with pasta and rice. Because of its high calorie content, it was believed that eating fat made us fatter and increased our risk of heart disease.
To understand how we got to this spectacularly low point in our collective health history, we must go back in time a little. In 1955, US President Eisenhower suffered a heart attack and his chief physician was instructed to tell Americans how to avoid heart disease. Stopping smoking and cutting down on fat consumption was based on research by Ancel Keys and others. The charismatic and convincing Keys provided the answer that everyone was looking for. The advice to eat a low fat diet was eagerly taken up by doctors and the public. The new low fat revolution had begun.
Meanwhile, in the UK some British scientists remained sceptical. The most prominent among them was Professor John Yudkin, who was struck by the correlation between heart disease and sugar, rather than fat. After all, sugars were a relatively recent addition to the western diet. Saturated fats, by contrast, are so bound up in our evolution that they are abundant in breast milk. It seemed clear to Yudkin and others that it was sugars, not fats, that were driving the heart disease epidemic.
Throughout the 1960s the debate between those in the Keys camp and the supporters of Yudkin raged on. In 1972, Yudkin published a book called Pure, White, and Deadly, which outlined the argument against the low fat movement, but marked the end of Yudkin’s career. The food industry destroyed his reputation and the low fat, high carbohydrate movement gained momentum.
Fast forward to today and we are at last realising that there may have been a sugar grain of truth in Yudkin’s work. Scientists such as Robert Lustig have embarked on high profile campaigns against sugar and new research has reached the conclusion of almost every government that it is in fact sugar, not excessive fats, that have put us in the health crisis in which we now find ourselves.
So, why do we need fats, I hear you ask? Dietary fats are a key part of a healthy diet. They provide energy, help us feel fuller for longer, help keep our blood sugars more stable and help us to produce and regulate our hormones. As well as all this, fats help us absorb some key nutrients known as the fat soluble vitamins. As the name implies, vitamins A, D, E and K require dietary fat in order to be absorbed and used by the body. Low fat diets can result in low levels of these vital nutrients.
Which fats should we be eating?
Don’t get me wrong – I’m not suggesting we all go out and feed up on deep fried chips or daily greasy spoon breakfasts. As with most things, there are good and less helpful fats. The fats we need to be including into our diet are monounsaturated (MUFAs), polyunsaturated (PUFAs) and omega-3 fatty acids.
The MUFAs and PUFAs, as I like to call them, are found in foods such as nuts, seeds, olive oil, flax oil, and avocado. Anti-inflammatory omega-3 is great for supporting heart health as well as mental health and mood. These fatty acids come predominantly from oily fish – the acronym SMASH is a good way to remember them. Salmon, mackerel, anchovies, sardines, and herrings, but it can also be found in grass-fed meat (not corn-fed), flax oil, flax seeds, walnuts, and chia seeds.
Which are the bad fats?
The fats we want to avoid eating too much of are oils such as vegetable, sunflower, corn and soybean oils. These contain high levels of omega-6 fatty acids, that can be pro inflammatory.
Saturated fats were originally demonised as being the culprits causing heart disease but are now an important part of the diet. Saturated fats are found in foods such as butter, cheese, milk, coconut oil and meats such as pork, beef and lamb and are generally solid at room temperature (as opposed to the MUFAs and PUFAs which are liquid at room temperature). These can all be healthy additions to a well-balanced diet; having around 10 per cent of your daily intake of calories in the form of saturated fat is recommended. Indeed, butter is significantly less processed than much of the ‘healthier’ margarines.
Finally, there are the artificial trans fats (aka partially hydrogenated fats). These wicked witches of the fat world are vegetable oils that are chemically altered to stay solid at room temperature and give them a longer shelf life. They were banned in some European countries in recent years, though notably not the UK. However they can still be found in small amounts in foods that have been cooked at a high heat – foods like biscuits and crackers. Avoiding processed foods can help to reduce the risk of consumption of these trans fats, which are known to be hazardous to your health.