Contrary to years of being told that a low fat diet is the way to go current research indicates that dietary fat is no longer the enemy. Despite reducing our fat intake over the past 40 years, rates of obesity and diabetes are higher than ever . Meanwhile studies assessing the effects of the Mediterranean diet, rich in monounsaturated fats, reveal healthy populations with lower rates of cardiovascular disease . It is now clear that dietary fats are an essential part of a ‘healthy’ well balanced diet.
Knowing the difference between foods that are ‘good’ fats vs bad fats is key to preventing disease and living a healthy lifestyle. So read on to find out if you are including the right fats in your diet and what amount you should be eating every day.
Why do our bodies need fat?
Fat is an essential macronutrient; meaning that it is required in moderately large quantities for optimal health and physical form.
- Fats form the lipid bilayer, a membrane of fat that surrounds nearly every cell in our body. This membrane acts as a barrier controlling things going into and out of the cell and without it, our cells would not be able to function (as there would be nothing to keep the contents of the cell separated from their surroundings)
- Fats play a vital role in brain function (our brains are made of up to 60 % fat),
- Fats play a key role in hormone storage and modification, particularly in the female hormone, oestrogen
- Fats are essential to absorb and benefit from the fat-soluble vitamins: A, D, E and K. These 4 essential vitamins can only be transported around the body dissolved in fat.
- Fats are as important to your diet as carbohydrates are in providing your body with slow releasing energy.
What are the different types of fats and which ones should we be eating?
Although we are now clear that eating fats are essential for optimal health, it is vital to be aware of which types of fat to eat as some fats will improve our health whilst others will weaken it.
The Good Fats
Unsaturated fats are considered to be the ‘good fats’ in that they provide our bodies with nutrients and numerous health benefits as well as fuel. There are two broad categories of ‘good’ unsaturated fats:
- Monounsaturated fats and
- Polyunsaturated fats
There are two types of polyunsaturated fats that are essential to human health; omega 3 and omega 6 fatty acids. They are referred to as the ‘essential fatty acids’ as although they are required by the body to build a host of other useful fat molecules they cannot be made in the body. This means including these fats in your diet is a MUST.
Moreover polyunsaturated fats have been linked with numerous other health benefits, reducing the risk of inflammatory disease such as heart disease and asthma .
Found in: Seafood and Fish (Salmon, Tuna, Sardines, Lobster), Nuts and Seeds (Walnuts, flax, chia) and Walnut and canola oils
Although not essential to our bodies, research has consistently shown monounsaturated fats to have a positive effect on the different types of cholesterol in our body, decreasing the ‘bad’/harmful (low-density) cholesterol whilst promoting the ‘good’(high-density) cholesterol. Subsequently eating foods that contain monounsaturated fats can reduce your risk of heart disease.
Found in: Nuts and seeds (almonds, cashews, peanuts, sesame seeds, pumkin seeds) Olive, hazelnut and almond oils and Avocados
The Bad Fats
The worst type of dietary fat that should be avoided is the kind known as trans fat. Trans fats are predominantly factory produced artificial fats that are used to extend shelf life.
Found in large amounts in : Processed foods (including cakes, pastries, biscuits, crackers, microwave popcorn), Fried Foods, Baked goods, Low-fat spreads
Why are they bad?
Trans fats increase the amount of ‘bad’/harmful LDL cholesterol whilst reducing the amount of beneficial ‘good’ HDL cholesterol in the bloodstream. They have been linked to countless diseases including heart disease, Alzheimer’s disease type 2 diabetes obesity (this is the only fat associated with weight gain) , liver dysfunction, infertility in women, and depression. When heated to smoking point these fats can oxidize releasing disease causing free radicals and it is believed that trans fats interfere with the bodys ability to utilize and absorb essential fatty acids.
The Fats That Fall In The Grey Area
Although saturated fats are generally classified as ‘bad’ fats (as they were believed to increase the ’bad’ LDL cholesterol)it is still widely debated if saturated fat is associated with heart disease;  and saturated fats are becoming more of a middle ground nutrient as opposed to outright bad as previously though.
Found in Animal products , like meat, butter, lard and cheese and Plant based oils like coconut and palm.
So What Does All of This Mean For our Daily Fat Intake?
- Trans fats should be avoided at all costs
- Eat limited amounts of saturated fats as part of a healthy diet and always opt for grass fed healthier sources. The NHS health guidelines recommend limiting the amount of saturated fats to less than 11 percent of your total daily That means if you eat about 2,000 calories a day, less than 220 calories (or 24 grams) should come from saturated fats. So in terms of common foods this equates to 160g of beef, 2tbsp butter, 1 1/4 of cup, shredded mozerella cheese
- Around 30% of your daily calories should come from unsaturated fats; So for someone averaging 2,000 calories a day, 600 of these calories should come from unsaturated fats. Yes, that is a relatively large amount of calories but remember these fats are essential for your body to function. To put this into perspective, 600 calories of fat equates to 3.5 handfuls of nuts, 5 tbsp of olive oil, 2 avocados, or 3 salmon filets.
- Even with ‘healthy’ ‘clean’ fats watch your portion sizes! There are 9 kcals of energy in every gram of fat eaten compared with 4 kcals for carbohydrate and protein. This makes fats even the ‘healthy ‘ kind very easy to over-consume. I recommend having 3-4 servings of healthy fats every day, where 1 serving equates to around: 1 handful of nuts, 1 Thumb sized block of peanut butter, 1 palm sized salmon fillet, ½ large avocado, 1-2 tablespoons of Healthy Oils
- Balance your Omega-3 and Omega-6 fatty acids otherwise this could have negative effects on your health (keep a look out for my upcoming article where this will be discussed further),
 www.gov.uk/government/uploads/system/uploads/attachment_data/file/33 8934/Adult_obesity_and_type_2_diabetes_.pdf