The primary role of carbohydrates (CHO) is to provide energy to the body especially during high intensity exercises. 1 gram of CHO yields 4kcal of energy.
CHO is stored in the form of glycogen, in muscles and the liver. Glycogen is broken down into smaller units of glucose, which is when metabolized, produced energy in the form of Adenosine Triphosphate (ATP).
At least 100g of CHO needs to be consumed daily, otherwise protein stores (e.g. muscles) will be used for gluconeogenesis, the production of glucose. Some cells, such as nerve cells in the brain and red blood cells, are totally dependent on glucose for energy.
CHO usually represent 40-50% of our total daily energy intake. Some common CHO are: rice, sugar, potaoes.
FAT
One gram of fat yields 9kcal of energy, as compared to 4kcal/g of protein and carbohydrate.
Not all fats are unhealthy for the body. Saturated fats (coconut and palm oil) and trans fatty acids (commonly found in processed food) are harmful to the body if taken in excess. They raise the concentration of Low Density Lipoproteins (LDL), a form of bad cholesterol.
On the other hand, ‘good’ fats are essential to the body, for purposes such as storage of fat soluble vitamins (A, D, E & K). Omega-3 fatty acids are an example of ‘good’ fats and can be found in cold water fatty fish (salmon, mackerel, herring, sardines) and flaxseed oil. Omega-3 fatty acids are believed to reduce clotting in the blood, and this reduces the risk of heart diseases.