Macronutrients are those that provide us with calories or energy. They are required in large amounts, for growth, metabolism and other bodily functions.
There are three macronutrients:
· Protein (4 calories per gram)
· Carbohydrate (4 calories per gram)
· Fat (9 calories per gram)
The three macronutrients are essential for survival. Each has differing functions within the body, affecting our hormonal system in various ways. Not all calories are equal, and despite the fact fat is higher in calories, we still need plenty of healthy fats in the diet, whilst being much more cautious with carbs.
Protein is made up of little building blocks called amino acids; some are essential, meaning they can only be obtained from the diet, whilst others can be produced in the body. Protein has numerous roles and is involved in virtually all cell function in one way or another. Some of the most notable include:
· Its thermic effect, meaning it can ramp up your metabolism
· Protein has a major role in making hormones and enzymes
· Essential for building and repairing the body’s tissues
· Immune function is reliant on the action of certain proteins
· An ability to improve insulin metabolism
We should get our protein from animal sources such as poultry, fish and meat. Although some protein can be found in lesser amounts from plant-based products they aren’t the ‘biggest bang for your buck’ to obtain protein.
Although carbohydrates are lower in calories than fat, the effects on the endocrine system are less favorable. Starchy and processed foods instigate a greater insulin response, which is, as you know something we want to avoid! Subsequently, we need to get the majority of our carbs from fresh veg and some fruits, as this will provide us with the fibrous material we need to preserve intestinal health and assist in waste elimination.
We do need some carbohydrate in the diet for normal functioning of the brain, central nervous system, kidneys and muscles to function properly. It is also the most readily available source of energy in the body.
When we have a lower carbohydrate diet, it is important that make sure we consume enough healthy fats. We need to get these from foods such as nuts, olive oil, coconut oil, and avocado. Fat has various functions in the body including:
· Normal growth and development
· It is used as an energy source
· Required for the absorption of certain vitamins, namely A, D, E and K
· Provides protection for the internal organs
· Maintenance of cell membranes
· Fat is used in the production of some hormones
The only other source of calories we have is ‘ethanol’ or alcohol, which provides 7 calories per gram, but as its not required for survival we wouldn’t class it as a macronutrient.
The key is to get a balance between each of the macronutrients to achieve the right quota of each for optimal body composition.