A Healthy Human Diet

A balanced diet is an important part of maintaining overall health and well-being. It involves consuming a variety of different types of nutrients and the right amounts, to support the body’s needs.

All organisms need nutrients to stay alive and healthy. There are many different types of nutrients, but they all fall into seven main categories:

  • Carbohydrates – A primary source of energy for the body. They are found in bread, pasta, rice, fruits, and vegetables
  • Proteins – Necessary for the growth, repair, and maintenance of tissues. They are found in sources such as meat, eggs, and legumes (e.g. beans, peas and peanuts).
  • Lipids (fats and oils) – A rich source of energy. They are found in sources such as butter, nuts and seeds.
  • Minerals – Essential for various bodily functions, including maintaining strong bones and teeth, regulating heartbeat, and supporting the immune system. There are 16 essential minerals and they are found in sources such as dairy foods, meat, and green leafy vegetables.
  • Vitamins – Essential for maintaining good health and are found in a variety of fruits and vegetables.
  • Water – Essential for maintaining proper hydration and supporting different bodily functions. 70% of the human body is made up of water- As we lose water through sweat, urine and breathing out, we must replace the water lost The exact amount of water you need to drink may vary based on your age, sex, weight, and level of physical activity.


Although fibre cannot be absorbed by the body, it is an important part of a healthy diet. Fibre passes through the digestive system largely intact, providing bulk and helping to move waste through the intestines.

  • Foods that are high in fibre can reduce constipation

We can find fibre in plant-based foods such as fruits, vegetables, grains and legumes.

Energy Calculations

A balanced diet is essential for optimal health and involves eating a variety of foods that provide the body with the nutrients it needs to function properly. The recommended dietary allowance (RDA) is a set of guidelines issued by the government. It provides information on the right amount of each nutrient that should be consumed daily to meet the needs of 97% to 98% of the population.

For the NHS guide to maintaining a healthy weight:

  • The average man needs about 2,500 kcal (10,500 kJ) per day
  • The average woman requires 2,000 kcal (8,400 kJ) per day

However, the RDA is just a general guideline and the nutrient needs of each individual may vary based on factors such as age, gender, and level of physical activity.

The government introduced a traffic light system, which tells us whether a food has a high, medium or low amount of fat, saturated fat, sugars and salt. For example: