Macronutrients: What Do You Need To Keep Your Body Healthy?

Our body needs nutrients to keep it functioning correctly. These nutrients are chemical substances that are obtained from the food in our diet and used for energy and to provide growth and tissue repair. Nutrients we take in through food are divided into two main categories: Macro and Micro. Macros are the carbohydrates, fat and proteins and micro covers all the vitamins and minerals. The macronutrients make up the largest portion of our daily intake — hence the term macro. Other important food groups we need, such as water and fiber, are not as important as the macronutrients themselves.

Carbohydrates

This is the body's major macronutrient, but it does receive a lot of bad press from fad diets that think eating it in too high a quantity leads to weight gain and an inability to lose weight. Before you can begin to decide how much you need surely you need to understand exactly what it does for our body.

Carbohydrate is essential in the body because it is broken down during digestion to form glucose, which is further broken down to provide energy. This energy is used to allow us to exercise and go about daily life but also to keep our brain functioning effectively. This is why breakfast is usually wheat based, as the carbohydrates get our brain working and until we feed it, it is working at a lower rate. Another function of carbohydrate which is less talked about is to keep the liver functioning. If our liver is not at its optimum, it cannot deal with toxins in the body and that will lead to illness and also our levels of hormones can be affected.

When carbohydrates are broken down into glucose, this can be absorbed into the bloodstream and used straight away or it is stored as glycogen in the muscles and liver for use at a later date. Athletes will carbo load to make sure they have as much energy as possible before a big event. The body can only store 1600 calories of glycogen (enough for 2 hours running), so anything we eat over this could potentially be stored as fat.

There are different forms of carbohydrate, in actual fact carbohydrates are made up of molecules of sugar which are called saccharides. Different forms have different numbers of saccharides which effects how quickly they are digested:

• Monosaccharide - one molecule of sugar (glucose/fructose)
• Disaccharide - two molecules of sugar (sucrose/lactose)
• Polysaccaride - ten or more molecules of sugar

Mono and disaccharides are often called simple carbohydrates because they are broken down very quickly as they are only simple chains or single molecules. However, polysaccharides are multi-chain and known as complex carbs which take a lot longer to break down and therefore longer lasting energy. Simple carbs are foods such as table sugar and sweets, whereas complex carbs are the whole-wheat versions such as wholemeal pasta and bread.

Protein

The word protein is actually derived from Greek and means "prime importance". Proteins are of prime importance because they are the essential building blocks of life and make up the structures of the body such as skin, hair, muscle and bone. Without protein these body parts would not exist and would break down easily.

See Also: Just Say No To Sugar

If we were to break down a protein, you would see that it is made up of long chains of amino acids which are the smallest units of a protein. Amino acids are a bit like the alphabet which has 26 letters from which we can make up millions of words: there are 20 amino acids which make up all different types of proteins to make the varying structures of the body. These are split into essential and non-essential amino acid groups, an essential amino acid must be eaten through the diet and the non-essential aminos can be produced by the liver. This is why it is important to eat a range of protein-rich foods because you need to eat all the amino acids otherwise it affects recovery — a bit like if you suddenly couldn't use the letter E anymore!

Difference Between Complete And Incomplete Protein

We need to gain 8 essential proteins from our diet and 12 non-essential proteins that we make in our body. A food that contains all 8 essentials is called a complete protein, whereas if 1 or more are missing it is called incomplete. With the exception of soya, complete protein comes from animal sources while incomplete protein comes from vegetables, but you need to eat a range of sources of incomplete protein to get the right amount or eat complete proteins. Examples of complete proteins are chicken, eggs, red meat and soya beans and incomplete can be wheat, oats, rice, pulses, nuts and vegetables. If you eat beans on toast that's two incompletes (wheats and beans) so helps to build up the amino acids!

Fats

The most commonly hated food source is fats. Again, it receives a lot of bad press but is in actual fact a major part of our daily intake.

The functions of fats are to form cells, form the myelin sheath that coats nerves, protects organs and insulates the body and many more. Fats are part of the lipid family which predominantly supply energy for everyday activities and movements but they are quite calorie dense, with 1g containing 9 calories. Oil and fat come from the same family. The only difference is that fat is solid at room temperature and oil is liquid. For example, animal fat goes solid after cooking, whereas olive oil stays oil.

There are two main types of fat: saturated and unsaturated. Saturated fat is the worst of the two types because their molecular form doesn't change and cannot be broken down. So when you eat animal fat that has melted it becomes a liquid or oily form but if it is not broken down and digested then it is stored (just like the white fat you clean from the baking tray!). And this is the same as saturated and hydrogenated fats that are added to foods to make them last longer. However, unsaturated fats such as olive oil have health benefits and are useful within the body. 

Having said that you do need a level of both types but no more than 10% should be saturated fats.

How Much Of Each?

Each gram of carbohydrate, protein and fat has a calorie amount. One gram of carbohydrate has 4 calories as does protein and fat has 9 calories per gram. You can use this to work out how many of your calories come from each macronutrient source. For example if there are 100 calories in sandwich it usually tells you on the packet the percentage of macronutrients are within the sandwich. And ideally you want the fat to be lowest proportion - but in a lot of cases of processed food this isn't the case.

See Also: Fat Vs. Carbs: Which One Is Really To Blame?

Carbohydrate should make up about 50-60% of your daily diet. The British Nutrition Foundation found the average intake in men was 272g and women 193, equalling just over 45% of their total. Protein should make up somewhere between 10 and 30% depending on the needs of the individual, another way to work this out is for every pound of body weight equals 1g of protein (100lb man needs 100g of protein). Fat intake should be no more than 30% and saturated in particular no more than 10%. These numbers will vary depending on the size and weight of the individual and there are lots of calculators on the internet to help you estimate your daily balance.