Duncan Farrington takes a closer look at the different types of fats and clears up some of the confusion surrounding them:
We often hear contradicting messages about what we should and should not eat in our diets, we are told some foods are ‘good’ and others are definitely ‘bad’. It is confusing and frustrating sometimes not knowing what to do for the best. I really believe in keeping things simple when it comes to eating a healthy diet, plus being honest with myself in the choices I make. For example, I personally enjoy spending an evening with friends over a couple of beers, but if I was to do this every evening of the week, over time it would lead to unhealthy consequences. The choice is mine.
In our diet, we need the right balance of macro and micro nutrients. Macro nutrients are the main food groups of carbohydrate, protein and fat. If we eat a balance of the three macro nutrients, preferably in as broader range of different foods as possible and ideally in a non-processed diet, we will also get all the micro nutrients of minerals and vitamins needed in our diet too.
As a very simple rule of thumb, a healthy diet consists of plenty of fruit and vegetables, plus around a third of our daily food intake coming from each of the main food groups – carbohydrate, protein and fat.
Carbohydrates are found in foods such as cereals and rice, bread, potatoes, pasta, sugar.
Proteins are found in meats, fish, pulses.
Fats are found in cooking oils, fats and nuts.
It can become more confusing when we consider that most foods contain a mixture of the different food groups. For example, milk and dairy foods contain carbohydrates, proteins and fats as well as important vitamins and minerals. Fruits are a great source of minerals and fibre, but also contain carbohydrates (sugars). Eggs have both protein and fat. However foods such as biscuits and cakes are equally high in fat and sugar.
Fat is a crucial part of our diet, it is the most efficient source of energy, it helps our bodies absorb fat soluble vitamins, such as vitamins A,D,E and K. Fats play crucial roles within our bodies from cell membrane formation, to the development of our brain and even communication between different cells. They also insulate organs and contribute towards maintaining body temperature.
Like other food groups, fats are also complex, they are formed from fatty acids and can be split into three main types; Saturated, Poly-unsaturated and Mono-unsaturated. These terms are simply a description of the molecular make up of the particular fatty acid in ratio of the carbon to hydrogen atoms and how they are bonded together. Don’t worry about the chemistry – I struggle with it myself. However, just as we need a balance of macro nutrients in our diets, we also need a balance of the different fats, with around an equal split between saturated, poly-unsaturated and mono-unsaturated fats being a simple rule of thumb.
The much-heralded Mediterranean diet is shown as an example of healthy eating, where the population had much lower cases of heart disease compared with northern European populations. The Mediterranean diet is low in saturated fat, mainly comprising of olive oil, oily fish which contains poly-unsaturated fats and plenty of fruit and vegetables. This compared with a traditional northern European diet which is high in saturated fat, mainly from animal fats and not enough fruit and vegetables. It is important to recognise that the total fat consumed in the two diets was similar, it was just that one was in the right balance, where the other was not.
An easy way to recognise a saturated fat is that it is solid at room temperature, only becoming liquid once it is heated. Over the years, successful health messages have resulted in greater awareness of the need to reduce our saturated fat intake in Britain, which has been largely successful. We now eat less fatty meat and more sources of plant-based fats.
Oily fish is an important part of the Mediterranean diet because it is a good source of poly-unsaturated fatty acids. Poly-unsaturated fatty acids play vital roles in the reduction of cholesterol in our bodies as well as being crucial for healthy brain and eye development. They are often called essential fatty acids, as the body can only get them in the diet and can not make them internally. These fats can also be found in certain nuts and seeds such as rapeseed, sunflower seed or peanuts. As nutritionists became aware of the need and role of poly-unsaturated fats in the diet following World War II, food companies developed non-dairy spreads to replace butter which has a higher saturated fat content with ‘healthier’ alternatives such as sunflower or corn oil, these have less saturated fat and higher poly-unsaturated fats. However, over the years, knowledge and learning about these complex fatty acids increased, to discover that poly-unsaturated fats are also made up of different types which can be broadly categorised in to Omega 3 and Omega 6. Not only did scientists discover the different types of poly-unsaturated fats, they also discovered that bodies need to consume these in an ideal balance of around two parts of Omega 6 for every one part of Omega 3.
With this new-found knowledge, it was also realised that the oils traditionally used to make non-dairy spread, were good sources of Omega 6, but had little or no Omega 3. Additionally, people who eat a high proportion of processed foods, much of it using sunflower, corn or palm oils for example, were in fact eating an unhealthy ratio of Omega 6 to Omega 3 of up to 20 times to 1, compared to the ideal of 2 to 1, causing other bad health issues in our diet. Some responsible food manufacturers have recognised this problem and have replaced such unbalanced fats with better options. A good example is a leading brand of non-dairy spread which used to be made with sunflower oil, which had the strap line in advertising campaigns in the 1980’s about it being ‘high in poly-unsaturates’, even though sunflower oil has no omega 3. The recipe was completely changed to replace sunflower oil with rapeseed oil, which has the perfect balance of poly-unsaturated fats in a ratio of 2.6g of Omega 6 for every 1g of Omega 3.
The final type of fat we need in our diet is mono-unsaturated. Mono-unsaturated fats are found in plant foods such as nuts and seeds, with olive oil and rapeseed oil being rich sources of these fats, as well as avocados for example.
For more information on the role of fats in our diet, look at https://www.farrington-oils.co.uk/interesting-oil/ which also includes three excellent articles form the British Nutrition Foundation.
As I said at the start, information and advice can be confusing and frustrating, but for my part I stick to my own rules of:
Eat a well-balanced diet, around a third each of carbohydrate, protein and fat
The broader the diet of different foods and meals I enjoy, the better
Eat a well-balanced diet of the different fats
‘Good’ and ‘Bad’ foods don’t really exist, it is just the quantity of each that makes a difference
Be honest with yourself – I know what treats to enjoy sparingly and what I should eat more of. More cabbage, less biscuits!