Lesson 4 of 9
When a diet goes wrong
Goal: Describe the effects of an unbalanced diet.
An unbalanced diet has too little or too much of something. Over a long time, this harms health.
- Starvation is taking in far too little energy for a long time. The body uses up its stores of fat and breaks down muscle. The person becomes very thin and weak, and falls ill more easily.
- Obesity. If a person takes in more energy than they use, the body stores the extra as fat. Obesity means having so much stored fat that it can harm health. It raises the risk of heart disease and type 2 diabetes.
- Malnutrition means that the diet has the wrong balance of nutrients. A person can eat plenty of food and still be short of a vitamin or a mineral.
Swipe to see four deficiency diseases. Each one is caused by too little of one nutrient.
Anaemia
Too little iron
The body has too few healthy red blood cells, so the blood carries less oxygen. The person feels tired and looks pale.
Scurvy
Too little vitamin C
Gums bleed and wounds heal slowly. Fresh fruit and vegetables give vitamin C.
Rickets
Too little vitamin D
A child’s bones stay soft and can bend. Your skin makes vitamin D in sunlight. Oily fish and eggs give it too.
Night blindness
Too little vitamin A
The person cannot see in dim light. Carrots, green vegetables, eggs and milk help the body to get vitamin A.
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Key words in this lesson
Deficiency disease An illness caused by too little of one vitamin or mineral
Starvation Taking in far too little energy for a long time
Obesity Having so much stored body fat that it can harm health