Eating a healthy diet is as important for health and wellbeing as being physically active, not smoking, and limiting consumption of alcohol. A healthy diet is one that provides the right amount of nutrients and calories for the body to function properly through consumption of a wide variety of foods, and achieve and maintain a healthy weight. Use the NHS calculator to check your body mass index (BMI) and find out if you’re a healthy weight.
Eating the right food helps children grow and develop both physically and mentally, and gives everyone enough energy to stay fit and active. It also is necessary for wound healing and repairing other injuries, as well as reducing the risk of many diseases.
A poor diet increases the risk of overweight and obesity which can lead to developing many serious health conditions, such as:
- Type 2 diabetes
- Heart disease
- Certain types of cancer
- Tooth decay
- Vitamin and mineral deficiencies
Overweight and obesity
A healthy diet contains the right amount of nutrients and calories to achieve and maintain a healthy weight, and the amount needed varies depending on a number of factors, including sex and life stage (e.g. such as during childhood, adolescence and pregnancy).
Excess weight occurs when the calories consumed are regularly above what the body requires to function and perform daily tasks. People living with excess weight have an increased risk of developing different illnesses, including but not limited to type 2 diabetes, high blood pressure, heart disease, liver disease, stroke and some cancers.
Eating a healthy diet and being active reduces the risk of being overweight or obese. Two thirds of adults in Scotland, and almost a third of children are now at risk of being overweight or obese.
For more information on living with Obesity, please see the NHS website - Obesity.
It is important for a healthy diet that the right amount of nutrients and calories are consumed to achieve and maintain a healthy weight, and if less calories are being consumed than the body is expending, underweight can occur.
If someone is underweight this can lead to nutritional deficiencies, such as calcium deficiency which can risk the development of osteoporosis (fragile bone disease) in later life, or iron deficiency which can make someone feel drained and tired. Being underweight can also cause a weakened immune system and can make someone more susceptible to catching a cold, flu or other infections.
For more information on underweight, please see the NHS website – Underweight Adults.
Type 2 diabetes
Diabetes is a lifelong condition that causes a person’s blood sugar level to become too high. There are two types of diabetes:
- Type 1 diabetes is an autoimmune disease where the body’s immune system attacks and destroys the cells that are responsible for producing insulin. Type 1 diabetes is not related to overweight or obesity, and there are no lifestyle changes that can lower a person’s risk of type 1 diabetes.
- Type 2 diabetes occurs when the body does not produce enough insulin, or the body’s cells do not react to insulin. Type 2 diabetes is often associated with obesity, and so maintaining a healthy balanced diet and being physically active can help to reduce the risk of developing type 2 diabetes.
Type 2 diabetes is much more common than type 1, with 87% of all adults in the UK with diabetes having type 2. If left untreated, type 2 diabetes can have serious consequences including kidney, eye and foot damage, hearing impairment, and heart and blood vessel disease. Drinking lots of sugary drinks can also increase the risk of developing type 2 diabetes.
For more information on diabetes, please see the NHS website – Diabetes.
Cancer is one of the leading causes of death in Scotland. Overweight and obesity is the second biggest cause of cancer in the UK, with more than 1 in 20 cancer cases caused by excess weight. Whilst living with overweight or obesity doesn’t mean an individual will definitely develop cancer, they are much more likely to get cancer than if they are a healthy weight.
Extra fat in the body doesn’t just sit there, it's active, sending out signals to the rest of your body. These signals can tell cells in our body to divide more often, which can lead to cancer.
Overweight and obesity increases the risk of 13 different types of cancer. This includes:
- Breast and bowel (two of the most common cancer types)
- Pancreatic, oesophageal and gallbladder (three of the hardest to treat cancers)
- Womb and ovarian
- Kidney, liver and upper stomach
- Myeloma (a type of blood cancer)
- Meningioma (a type of brain tumour)
40% of cancers are preventable through lifestyle changes, including:
- Eating a healthy diet
- Achieving and maintaining a healthy weight
- Being active
- Not smoking
- Avoiding drinking more than 14 units of alcohol a week
Heart disease is another leading cause of death in Scotland, but 80% of heart disease is preventable.
There are several ways to reduce the risk of developing heart disease:
- Lowering blood cholesterol by reducing the amount of saturated fat in the diet
- Lowering blood pressure by reducing the amount of salt in the diet
- Eating at least one portion of oil-rich fish a week, such as mackerel, salmon and herring, which contain omega-3 fats can help protect against heart disease
- Achieving and maintaining a healthy weight
- Not smoking
In 2020, 26% of primary 1 children in Scotland had obvious dental decay.
In 2019, 20% of primary 7 children in Scotland had obvious dental decay.
Too many sugary foods and drinks in the diet can cause tooth decay, especially if eaten between meals.
Fruit juices and smoothies are high in sugar which can harm teeth, so consumption should be limited to meal times and a combined total of 150ml per day.
Tooth decay can happen at any age, so reducing the quantity and frequency of sugary food and drink consumption, as well as regular brushing will help prevent tooth decay.
Vitamin and mineral deficiencies
Vitamins and minerals are nutrients required by your body in small amounts to stay healthy. A lack of these essential vitamins and minerals can lead to deficiency diseases, including, for example:
- Anaemia caused by iron deficiency
- Bone problems caused by vitamin D or calcium deficiency
Most people should get all the nutrients they require from a varied and balanced diet, but sometimes supplements may be required. For example, whilst most people in Scotland can get all the vitamin D they require from sunlight between the months of April and September, we may need to rely on dietary sources of vitamin D between October and March. As vitamin D is only found in a small number of foods, it might be difficult to get enough from foods alone, and therefore a daily supplement might be required during these winter months.
Some supplements may also be required to treat vitamin deficiencies, such as the need for iron supplements to treat iron deficiency.
Food allergy and intolerance
A food allergy is when the body’s immune system reacts to specific foods. Whilst most allergic reactions to food are mild, some can be very serious, and the only way for people to deal with a food allergy is to avoid the foods that make them ill.
A food allergy is different from a food intolerance as a food allergy involves a reaction in the immune system and can cause symptoms within a few minutes of eating or being exposed to the allergen. However, a food intolerance is caused by the body being unable to digest certain substances (e.g. lactose in milk), and does not involve the immune system. Symptoms of food intolerance tend to be slower to present than food allergies and may not be felt until a few hours after eating the food.
For more information on allergens, see our following website sections:
- A healthy diet is one that provides the right amount of nutrients and calories for the body to function properly.
- Overweight and obesity can lead to the development of many serious health conditions.
- Type 2 diabetes is much more common than type 1 diabetes, with around 90% of all adults in the UK with diabetes having type 2.
- Overweight and obesity is the second biggest cause of cancer in the UK.
- Tooth decay can occur from a diet that is too high in sugary foods and drinks, especially when consumed between meals.
- Almost 70% of our immune cells are stored in the gut.
- Vitamins and minerals are nutrients that are found in different foods and are required by the body in small amounts to stay healthy.
- A food allergy is when the body’s immune system reacts to specific foods.
Module 1 quiz
Answer the questions below to see what you've learned and to complete module 1.
Why is a healthy diet important?
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Type 2 diabetes increases the risk of which of the following?
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Which of the following are ways to reduce the risk of developing heart disease?
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