The Basics Of What Our Body Needs

A Balanced Diet

Have you ever heard the phrase ‘We are what we eat’?

It was Hippocrates’ observation about diet that still has relevance 2,000 years later. In essence ‘we are what we eat’, means the raw materials from which our bodies are constructed, are provided by the food we eat. Normal daily living dictates that even when fully grown, our bodies require constant repair and maintenance. The many processes of living, moving, exercising and keeping warm also require fuel or energy which must come from food, or more precisely, the nutrients in food.

So everywhere we hear about a balanced diet. Looking into the dictionary, the definition of diet is ‘the kinds of food and drink that a person, animal or community habitually eats’. There is no mention of special foods or restrictions. Food should not be a misery, but a source of enjoyment! So let me ask ,who loves food?

The 3 key foundations of a balanced diet are:

  • Carbohydrates
  • Proteins
  • Fats

These are needed in large quantities each day, and are referred to as MACRO NUTRIENTS. Within these nutrients, and then through digestion and metabolism, MICRO NUTRIENTS are released, which are known as:

  • Vitamins
  • Minerals
  • Non starch polysaccharides (fibre)
  • Water

With that all said, a balanced diet is defined as having well-proportioned amounts from all food groups.


The main aim of digestion is to break large molecules of a nutrient into smaller molecules that your body can use effectively.

Did you know?

The small intestine is about 7 metres long, and about 2.5 centimetres in diameter. The surface area is around 250 square metres, or about the size of a tennis court!

We make 0.5 to 1.5 litres of saliva a day.

It takes your mouth, oesophagus, stomach, small intestine, large intestine, gallbladder, pancreas and liver just to digest a glass of milk.

An adult’s stomach can hold approximately 1.5 litres of material.

Food stays in your stomach for 3 to 4 hours.

Cells along the inner wall of the stomach secrete roughly 2 litres of hydrochloric acid each day, which helps kill bacteria and aids in digestion. To protect itself from the corrosive acid, the stomach lining has a thick coating of mucus which is replaced every two weeks.

When your tummy rumbles, it’s the normal movements in the digestive system. When the tract is empty, however, the noises are louder.

Within the colon, a typical person has more than 400 distinct species of bacteria.

We aim to have a balance of 80% good to 20% bad bacteria.

Digestion starts when enzymes are released in the mouth. It continues in the stomach.

Nutrients are absorbed from the small intestine into the blood stream or lymph system. These are then processed by appropriate organs and readied for use by the cells. Energy is generated through the metabolism of nutrients. The unwanted toxins and waste are then eliminated from the body.

Movement of food through the system

Mouth: Seconds

Oesophagus: Seconds

Stomach: Up to 3½ hours

Small Intestine: Minutes

Large Intestine: Hours   

Four basic functions of digestion:

Motility: Means movement from one end to the other of a nine metre tract. Caused by contractions of muscles.

Secretion: The process of various glands releasing digestive secretions to break down food.

Digestion: Breaks down food into its constituent parts by chewing and chemically by digestive secretions.

Absorption: Mainly takes place in the small intestine, passing to the transport systems of the lymph or blood stream to be used for energy or stored.

You are what you absorb

That includes the good (vitamins, minerals, and other nutrients) and the bad (environmental toxins, food additives etc.).

In the small intestine, all nutrients are absorbed, plus water and most electrolyte salts. The villi which are hair-like projections, line the interior surface of the small intestine, increasing its surface area. Nutrients pass across the villis’ cell membranes and enter into the bloodstream. In the large intestine, more salts and water are absorbed.

The less your body has of a specific nutrient, the more readily it will be absorbed. If you have a deficiency in, say, vitamin B6, your body will aggressively absorb that nutrient from your food source. Generally, you don’t have to worry about absorbing more nutrients than you need. That’s because your body constantly strives for homeostasis, a physiological term for balance.

Balance for your digestive system to function normally requires many components too. Key ones include Digestive Enzymes, Vitamins A, B, C and D, minerals magnesium, calcium and fibre.

Louise Riley
Author: Louise Riley