Fat generally has a bad press, but as discussed in a previous article (Fat ?), not all fats are bad for you. Indeed fat plays an important, even vital, part in the body's physiology and nutritional requirements. Without fat your body’s nervous system, hormones and immune system wouldn’t function. You’d be very susceptible to the cold and your skin would look more haggard as you got older because it didn’t have a layer of fat to plump it out as it started to lose its elasticity. These are just a few of the many reasons why you need fat in your life.
The fat you eat is broken down during digestion into smaller units of fat called fatty acids. Your body will store fat when it has a surplus of energy, i.e. it’s given more than it requires. Eating anything in excess will cause your body to store fat. However, because fats are so energy-dense, (a gram of fat provides 9kcal/37kJ of energy compared with 4kcal/17kJ for carbohydrate and protein) it is very easy to eat too many calories without noticing. So over-eating even good fats can lead to weight gain or becoming overweight.
Many people cut fat out of their diets and replace them with refined carbohydrates because of all of the bad PR given to fat. Consequently, they miss out on the benefits of healthy fats. However eating the right kinds of fats can have:
- a positive benefits on your heart-health,
- lower your LDL cholesterol levels (the bad type),
- improve cognitive function,
- fight inflammation,
- help control blood clotting,
- lower blood pressure and triglycerides.
Moreover, eating lots of refined carbs—like white bread and white rice—can increase triglyceride levels, which can contribute to heart and blood vessel disease, obesity and type 2 diabetes.
So what are the good fats and how do you ensure that you are getting the right amounts in your diet?
Unsaturated fats - the good guys
These come in two types monounsaturated and polyunsaturated. Their chemical structure and health benefits are slightly different. Healthy unsaturated fats are liquid at room temperature. It is possible to destroy the health benefits of unsaturated fats by either heating them, exposing them to excess light or through oxygen damage. For example Flaxseed oil must be refrigerated and kept in an opaque container to avoid being damaged. If oils, seeds or nuts start to smell or taste bitter, then the fats have been damaged and therefore, they should not be used if in this condition.
Monounsaturated fats raise HDL (good cholesterol) and lower LDL.
Good sources of monounsaturated fats are:
- Olive oil
- Canola oil
- Sunflower oil
- Peanut oil
- Sesame oil
- Nuts (almonds, peanuts, macadamia nuts, hazelnuts, pecans, cashews)
- Peanut butter
You can add more monounsaturated fats to your diet by sprinkling seed and crushed nuts on salads, mixing them in yoghurt or adding them to oats with some fruit for a healthy nutritious breakfast. Spreading nut butter (peanut, almond or cashew) on fruit makes a quick and easy snack that is guaranteed to keep you full and energised for hours.
Remember, nuts are high in calories (170 calories per handful) so it is better to sprinkle them rather than eat handfuls, and use nut butters in moderation. Another suggestion is to follow the Mediterranean tradition of having bread dipped in olive oil and balsamic vinegar, rather than a roll with butter.
Polyunsaturated fats lower triglycerides and fight inflammation.
Good sources of polyunsaturated fats are:
- Soybean oil
- Corn oil
- Safflower oil
- Sunflower, sesame, and pumpkin seeds
- Fatty fish (salmon, tuna, mackerel, herring, trout, sardines)
- Soya milk
Polyunsaturated fats include Omega-3, known as essential fatty acids, because the body cannot make them; they have to come from the food people eat.
The brain has high concentrations of Omega-3 fatty acids and research has shown that they play a vital role in memory and problem-solving abilities, as well as emotional health. There is some evidence that they can help in the treatment of depression, attention deficit/hyperactivity disorder (ADHD), and bipolar disorder.
For people who exercise regularly, increasing the amount of Omega-3 fatty acids in their diet can help them battle fatigue by providing more energy for working out and other daily activities. Trail mix (mixtures of seeds and nuts) and soya milkshakes make great choices for pre-workout – these polyunsaturated fat snacks will boost energy levels and cognitive abilities enabling the individual to act and think faster, and improve their performance.
Fatty fish like albacore tuna, salmon, mackerel, and sardines are good sources of Omega-3 fatty acids. For vegetarians or people who don’t like fish, algae such as seaweed is an alternative source of Omega-3.
Cholesterol (a fatty, wax-like substance that your body needs to function properly) is a type of fat of which there are good and bad types of cholesterol. HDL cholesterol is the "good" kind of cholesterol found in your blood. LDL cholesterol is the "bad” kind. Too much cholesterol can have a negative impact on your health.
Cholesterol comes from two sources: your body (specifically the liver which produces it naturally) and food e.g. eggs, meat, and dairy. The key is to keep LDL levels low, high levels of LDL cholesterol can clog arteries, increasing the risk of heart disease and stroke. The biggest influence on total and LDL cholesterol is the type of fats a person eats, rather than how much cholesterol is in their diet. Therefore, individuals should focus on replacing bad fats with good fats in their diets rather than fixating on cholesterol levels.
A hummus (which is rich in olive oil) or guacamole dip (avocados are high in monounsaturated fats plus they also provide fibre, potassium, magnesium, and vitamins C and E) with vegetable sticks (carrots, celery cucumber) or whole-wheat chips to dip, makes a healthy alternative snack to crips, cakes and biscuits which are high in the bad fats, like trans fats. Trans fats are the worst types of fat since they not only raise your bad LDL cholesterol, but also lower the good HDL cholesterol.
Having “fatty” snacks therefore can be a good thing! However, do not make the mistake of many who want to lose weight by focusing purely on the food you consume and cutting out lots of types of food (or even most food!) thinking this will help them lose weight. The fuel you put in your body has to be balanced – you need a good blend of different nutrients, proteins, carbohydrates, fats and so on – but it is the energy you expend that will really help make the difference. So do some exercise, get on that treadmill or go for a cycle, eat healthily, and start improving your overall wellness!