Module 2

Eating a healthy diet is as important for health and well-being as being physically active, not smoking, and limiting consumption of alcohol.

A healthy, balanced diet is one that provides the right amount of nutrients and energy (measured in calories/kcal) for the body to function properly through consumption of a wide variety of foods and helps to achieve and maintain a healthy weight.

A healthy balanced diet is necessary for growth and repair of the body. It is also important for maintaining a healthy weight, and helps to reduce the risk of developing:

• type 2 diabetes
• heart disease
• certain types of cancer
• tooth decay
• vitamin and mineral deficiencies

There are many things that affect body weight, including what and how much food and drink is consumed, physical activity levels, as well as things like family history, medication and the food environment that surrounds us.

A healthy diet contains the right amount of nutrients and calories to achieve and maintain a healthy weight. The number of calories that each person needs varies, and depends on a number of factors, including sex and life stage (e.g. such as during childhood, adolescence and pregnancy).

It’s difficult to know what an individual’s ideal weight should be. The most widely used method to measure and categorise a person’s body weight is body mass index (BMI). BMI is categorised into ranges:

• under 18.5 - this is described as underweight
• between 18.5 and 24.9  - this is described as the ‘healthy range’
• between 25 and 29.9 - this is described as overweight
• 30 and over - this is described as obesity.

While BMI can provide an indication of whether a person has a healthy weight for their height, it doesn’t measure body fat directly or consider factors such as muscle, age, sex or ethnicity; it doesn’t indicate an individual’s overall health.

Overweight and obesity occurs when the calories consumed are regularly above what the body requires to function and perform daily tasks. People living with overweight or obesity have an increased risk of developing a range of health conditions, including type 2 diabetes, high blood pressure, heart disease, liver disease, stroke and some cancers. Please see the NHS inform page on obesity for more information.

If someone is underweight, it could mean that their dietary intake is not meeting their needs, and they may be missing out on important vitamins and minerals, and may result in a weakened immune system that 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.

Diabetes is a condition that causes a person’s blood glucose (sugar) level to become too high. There are two main types of diabetes – type 1 diabetes and type 2 diabetes.

The hormone insulin – produced by the pancreas – is one of the hormones responsible for controlling the amount of glucose in the blood. There are two types of diabetes:

• type 1 diabetes is caused by the body’s immune system attacking and destroying the cells that are responsible for producing insulin. Type 1 diabetes is not related to body weight, 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 excess body weight, and so maintaining a healthy weight by eating 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 90% of all adults in the UK with diabetes, having type 2. Having type 2 diabetes increases your chance of getting other long term health problems including damage to your blood vessels, which can cause heart disease, problems with your kidneys, eye sight and feet. 

For more information on diabetes, please see the NHS website – Diabetes.

Lifestyle changes, including eating a healthy diet and achieving and maintaining a healthy weight, can help reduce the risk of developing certain cancers. 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. While not everyone living with overweight or obesity will develop cancer, maintaining a healthy weight can help reduce the risk.

Excess weight can increase the risk of developing 13 different types of cancer due to changes in the body that affect how cells function.

Around 40% of cancers are preventable through lifestyle changes, including:

• eating a healthy diet- focused on more fibre, fruit, vegetables and wholegrains, and less red and processed meat
• achieving and maintaining a healthy weight
• being active
• not smoking
• avoiding drinking more than 14 units of alcohol a week

For more information on cancer, please see the NHS Inform webpage on cancer.

Heart disease is a term used to describe a range of conditions that affect the heart. Eating a balanced diet and maintaining a healthy body weight can help reduce your risk of heart disease.

There are several ways to reduce the risk of developing heart disease:

• reducing the amount of saturated fat in the diet can help to control cholesterol levels in the blood. Too much cholesterol can build up in blood vessel walls, leading to heart disease
• reducing the amount of salt in the diet can help to lower blood pressure, which if too high can increase risk of heart disease
• 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
• eating at least 5 portions of fruit and vegetables a day
• eating plenty of dietary fibre, choosing wholegrain varieties where possible
• achieving and maintaining a healthy weight
• not smoking

For more information on heart disease, please see the NHS website – heart disease.

Tooth decay can happen at any age, so limiting consumption of sugary food and drinks, as well as regular brushing, will help prevent tooth decay.

The type of sugar we need to eat less of is called free sugar. This includes sugar added to food or drink, and those found naturally in honey, syrups and fruit juices.

The free sugars in our food and drink are one of the biggest contributors to tooth decay, especially if we eat them between meals.

Sugars found naturally in whole fruit are not as likely to contribute to tooth decay because the sugar is stored in the structures of the fruit. However, once you blend or juice the fruit the sugars are released and can cause more damage to the teeth. This is also true for dried fruit which release more sugar and sticks to the teeth, which can lead to more tooth decay.

To reduce the risk of tooth decay, it is important to:

• avoid giving children under the age of 5 years any food or drink sweetened with sugars or artificial sweeteners, sticking to water and pasteurised milk as their main drink
• limit your intake of fruit juice or smoothies to no more than (150ml) portion per day, having this as part of a meal rather than in between meals

Adults and older children should avoid sugary drinks. No added sugar, reduced sugar or sugar free versions can be a useful alternative to those with added sugar, as a stepping stone in reducing sugar intake. For more information on tooth decay, please see the NHS website – tooth decay.

Vitamins and minerals are nutrients required by your body in small amounts to stay healthy.

If the diet is low in essential vitamins and minerals, this can lead to health problems.

Most people should get all the nutrients they require from a varied and balanced diet, but sometimes supplements may be required.

Whilst most people in Scotland can get all the vitamin D they require from sunlight between the months of April and September, we 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. Everyone (including children) should consider taking a daily supplement containing 10 micrograms/µg of vitamin D (400 IU), during these winter months.

Some supplements may also be required to treat or prevent vitamin deficiencies.

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:

• allergens
• food allergens – Education Resources
• Online Allergy Training courses

• A healthy diet is one that provides the right amount of nutrients and calories for the body to function properly and can reduce the risk of developing certain health conditions
• Living with 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.
• 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