Spotlight on Macronutrients

What are macronutrients?

Macronutrients, or “macros”, are the main components of food that the body needs in large amounts to provide energy and in order to function properly. The three primary macros are carbohydrates, protein and fats.

Carbohydrates

Carbs are all sugars & starches. They come from sugar, fruit, bread, pasta, rice, flour, grains and starchy vegies. They are broken down to glucose, galactose and fructose. Fructose can't be used as fuel and is stored directly in the liver. Galactose is converted to glucose. Glucose is a fuel source and is either used immediately or stored for later. Glucose is not used for anything else other than as energy.

But here's the thing, we do NOT need carbs - they are NOT an essential nutrient. Our bodies can easily make glucose via a process called gluconeogenesis.

Carbs are very quickly absorbed into the bloodstream, and cause a rapid and big glucose spike. But this spike doesn’t last very long, and we feel hungry and tired again very quickly after eating.

Protein

Protein is made up of chains of amino acids. It can be used as a source of energy. We cannot survive without protein. It is used to build and repair tissues like muscle, bones, skin, hair and organs. It is required to make hormones, enzymes, antibodies, neurotransmitters and transporter molecules. We can't store protein and so need to eat it  everyday. Our body can make some amino acids but not all, there are essential amino acids which we must get from food. Protein is found in meat, poultry, fish, eggs, dairy, nuts and legumes.

Unlike carbs, protein does not cause a rapid rise in blood glucose. There is a slow, delayed rise over 4-5 hours via gluconeogenesis, a process where amino acids are converted into glucose by the liver.

Fats

Fat is another essential nutrient. It can be used as fuel in the form of ketones and fatty acids. It is required for absorption of the fat-soluble vitamins A, D, E and K. Fats are the building blocks of cell membranes & walls, hormones and chemical messengers. They are essential for brain health. Short-chain fatty acids are integral to gut health. There are essential fatty acids that we must get from food. Fats with the least processing are the healthiest, such as olive oil, nut oils, butter, avocado, oily fish (eg. sardines, salmon) and animal fats.

Fats have very minimal effect on blood glucose levels, with a slow release over 8-10 hours.