Why weight matters

You may be someone living with excess weight or you might be a friend, family member or carer of someone who is. Whatever your personal situation, learning more can help you better understand why weight matters.

Here, you can find out what ‘overweight’ is, understand what ‘obesity’ is, debunk some common myths  and learn how to have meaningful conversations with a healthcare provider.

Start exploring the topics that matter most to you by clicking the section buttons below.

Understanding excess weight

Symptoms

Causes

Common myths

Quiz

What is overweight?

'Overweight' is a term used to describe the condition of having excess fat on the body. Excess body fat affects more people than you might think. In fact, an estimated 2.5 billion adults in the world are overweight. In the UK, around 6 out of 10 adults are living with excess weight.

What is obesity?

Obesity is a serious, long-term condition that happens when there is a large amount of excess body fat. Living with obesity can affect a person’s day-to-day life. If this sounds like you, remember that with the right support and information, you can take charge of your weight and health.

How can I tell if I’m living with obesity?

Many factors like biology, lifestyle and environment can affect body weight. You can talk to your healthcare provider to find out if you are living with obesity and get a formal diagnosis. There are also ways to check if you are at a healthy weight, such as knowing your body mass index (BMI) and your waist-to-height ratio.

Body Mass Index (BMI)

Body mass index is a way of measuring if an adult is at a healthy weight for their height. A person’s BMI is calculated using their weight and height.

For most people, BMI is a useful indication of whether they’re at a healthy weight, but it is important to know that a BMI score has some limitations. BMI measures if a person is carrying too much weight but does not measure if they have too much fat. For example, an athlete can have a high BMI without too much fat.

In the diagram below, you can see what excess weight might look like on a person’s body.

BMI classification in adults

There are six BMI categories:

Underweight – below 18.5 kg/m²
Healthy weight – 18.5–24.9 kg/m²
Overweight – 25–29.9 kg/m²
Obesity class 1 – 30–34.9 kg/m²
Obesity class 2 – 35–39.9 kg/m²
Obesity class 3 – 40 kg/m² or more

BMI and ethnic background

A lower BMI score is used for categorising ‘overweight’ and ‘obesity’ in people who have an Asian, Chinese, Middle Eastern, Black African or African-Caribbean family background.

Overweight – 23–27.4 kg/m²
Obesity – 27.5 kg/m² or above

Waist-to-height ratio

You can measure yours in three simple steps:

Find the middle point between your lowest rib and your hip bone. This should be around the same level as your belly button
Take a tape measure and wrap this around the middle point. Breathe in how you normally would and do not hold your stomach in
Take your waist measurement and divide it by your height. Remember to measure it in the same units e.g. cm or inches

Here’s an example
If your waist is 80 cm and you are 160 cm tall, you would calculate 80 divided by 160, which equals 0.5.

A waist to height ratio of 0.5 or higher means you may have higher health risks.

The NHS website has tools available if you want to calculate your BMI score, or waist-to-height ratio. You can also speak to your healthcare provider for more information on these measurements and how this applies to you.

What are the symptoms of obesity?

Physical symptoms

Sweating more
Difficulty breathing
Snoring more
Feeling tired all the time
Problems with physical activity, such as walking or climbing stairs
Joint and back pains

Emotional challenges

Feeling alone
Depression
Having low confidence or self-esteem

What other health risks are linked to obesity?

Type 2 diabetes
Coronary heart disease
High blood pressure
High cholesterol levels
Heartburn
Sleep apnoea
Liver disease
Kidney disease
Fertility problems
Problems with pregnancy
Cancer, such as bowel, breast and womb cancer
Asthma
Gallstones
Osteoarthritis, pain and stiffness in the joints
Metabolic syndrome

You can find out more about the health risks of living with obesity on our beyond weight page.

What causes excess weight?

There are many factors that can cause a person to have overweight or obesity. Excess weight is complex and can be caused by a range of factors, such as:

Lifestyle and environment

The environment that we live in can make it difficult to have a balanced diet or do physical activity. Lifestyle factors, such as stress or poor sleep, can also affect weight gain.

Genetic causes

Genes can affect how the body uses food and stores fat. Lifestyle and environmental factors, like exercise, can affect how much genes play a role in obesity.

Underlying health conditions

Having an underlying health condition can cause weight gain. This includes conditions that are related to hormones that affect metabolism and appetite, such as an underactive thyroid gland.

Medicines

Some medicines can make people more likely to gain weight, including a range of treatments for high blood pressure, diabetes or mental health conditions.

Remember, you are not alone. Your healthcare provider is there to help support you in managing the challenges of excess weight. Find out how you can have open and meaningful conversations by using the ‘Talking to my healthcare provider’ guide.

Explore the guide

What are the common myths about excess weight and obesity?

Although obesity is recognised as a chronic and complex disease, it is still not widely understood.

Here, we debunk some common myths.

Myth: excess weight is caused by poor willpower or laziness

Truth: obesity is often thought to be caused by a lack of willpower or laziness. But this is far from the truth. In fact, there are many things that can cause excess weight, which you can explore in the section above.

Myth: obesity is not a disease

Truth: people often think that those who are obese have made poor lifestyle choices. However, obesity is recognised by experts worldwide as a complex, chronic disease. By recognising obesity as a medical condition, healthcare services and national governments can provide appropriate care for those affected. It also helps raise awareness to society that obesity is not caused by one’s poor willpower or laziness.

Myth: obesity is not a disease

Truth: childhood obesity is a serious health concern, which can have long–lasting effects. Children who have excess weight are more likely to stay overweight or live with obesity in their adulthood.

How well do you understand why weight matters?

Take this 2-minute quiz now to find out. This quiz covers everything from the causes of excess weight to debunking common myths. Get started now to learn more about this important health topic.

Think you might be living with obesity or excess weight?

Find out more about living with excess body weight.

Discover more

Guide: how to talk to your healthcare provider

Find out how you can have open and meaningful conversations with your healthcare provider.