Firstly, our bodies break down our food into the smallest particles in order to be absorbed through our digestive system, and into our body. Then those particles are rearranged, packaged and delivered to cells to be used for many purposes. Fats and oils from our foods will get used in many ways:
- To absorb the fat-soluble vitamins A, D, E, & K
- To make hormones and neurotransmitters
- To make the cell walls for every new cell - we make 100's of millions each day!
- For fuel for cellular activities and functions
- To produce energy and enable us to do things during the day
- For weight loss!
- For proper functioning of nerves and the brain
- To maintain healthy skin and membranes
- And many other uses!
Secondly, there are some fats we MUST eat regularly, as they are called "essential fatty acids", or just "essential fats". These are omega-3 and omega-6 fats - and they are essential because our bodies cannot make them! We need to eat these fats in our diet! Good sources of omega-3 fats include fish (salmon, tuna, mackerel, trout, sardines etc, with the skin on!), raw nuts and seeds, eggs, avocados and grass-fed meats (not grain-fed!). Good sources of omega-6 fats include some vegetable oils, raw nuts and seeds, butter, eggs, and dairy products.
Thirdly, the other issue with fats is which ones are safe and healthy to cook with. Without getting into too much chemistry, plant-based oils should never be used for cooking with! The only exception is coconut oil, which is a healthy saturated fat oil. The reason is that all other plant-based oils contain mono-unsaturated and poly-unsaturated oil, but when these are heated, they change their fragile structure and become oxidised, full of health-damaging free-radicals and other toxic breakdown products such as aldehydes.
A recent experiment was performed in the UK where various cooking oils were heated to normal cooking temperatures to see what effect this had on the oils. The allegedly "healthy" sunflower and other vegetable oils produced aldehydes at levels more than 20 times the World Health Organisation's safe levels! Olive oil fared better, but it still isn't recommended for heating and cooking with. Butter and other animal fats were stable and the safest for cooking! Coconut oil is also stable when heated and is also recommended. The plant-based oils are ok as a dressing on foods only, or for massage! I recommend olive oil as being the healthiest for dressings on foods - mix it with various herbs and spices, and Balsamic or other vinegars for a tasty and healthy dressing!
While most fats can be healthy, the exception is trans-fat, which is found in fried foods, processed and packaged foods, and margarine. It is trans-fat, and oxidised vegetable oil (from heating and cooking), which causes inflammation in the body and this is a leading cause of all chronic health conditions, such as heart disease, weight gain and obesity, diabetes, infertility, and even cancer.
For your overall health, you need to eat the right fats and oils, and avoid the wrong ones!