Overweight

Being overweight means having more body fat than is considered healthy. The World Health Organization (WHO) says someone is overweight when their body mass index (BMI)—a calculation of weight divided by height—is between 25 and 30 kg/m². When BMI is above 30, a person is considered obese.

Overweight conditions are very common today, especially in places where there is plenty of food and people do not move around much. In 2003, more than 1 billion adults worldwide were overweight or obese. By 2013, this number had grown to more than 2 billion, showing how widespread this issue has become.

Our bodies need some fat to work properly. Fat helps with hormones, protecting sensitive areas, providing energy, and supporting the immune system. However, having too much fat can make it hard to move and stay flexible. Some people naturally have more body fat, and movements like body positivity aim to stop body shaming and help people feel better about themselves.

To manage being overweight, the most common advice is to change diet and increase exercise. For some, support groups such as Overeaters Anonymous or help with mental health can be useful. In certain cases, doctors may suggest weight loss drugs to assist with weight management.

Classification

See also: Body fat percentage

The body mass index (BMI) is a simple way to check if someone has a healthy amount of body fat. BMI is calculated by dividing a person's weight in kilograms by the square of their height in meters.

A BMI of 25 or more means a person is considered overweight. This includes those with a BMI between 25 and 29.9, who are sometimes called "pre-obese." People with a BMI of 30 or more are classified as obese. While BMI is the most common way to measure overweight and obesity, other methods exist that can be more accurate but are also more complicated.

Health effects

Having extra weight can affect health in different ways. Some studies show that having a bit more weight than what doctors think is healthy might not always be bad. For example, some older adults with a bit more weight can live just as long as those with less weight.

But having too much weight can also cause problems. It can make it harder for the body to use sugar properly, which can lead to a health issue called type-II diabetes. Extra weight can also make some health problems more likely, such as certain kinds of cancer.

People with more weight sometimes face unkind treatment from others, which can affect how they feel about themselves. It can also increase the chances of feeling very worried or sad.

Causes

Being overweight happens when someone eats more calories than their body uses up through activity and daily movements. This can happen for many reasons, such as not moving much, eating too much, or having certain health conditions.

Other factors that might play a role include not getting enough good sleep, having hormonal changes, or taking certain medicines. Sometimes stress or stopping smoking can also affect a person's weight.

Treatment

The usual ways to help someone who is overweight are diet and physical exercise.

Experts suggest eating balanced meals throughout the day and doing regular, mostly aerobic exercises. Research shows that these changes can help children aged 12 to 17 years manage their weight. Changing habits like eating better and being more active is important for staying healthy.

Epidemiology

The World Health Organization (WHO) said that in 2016, nearly 2 billion adults around the world, aged 18 and older, had more body fat than is healthy.

In the United States, about 71.6% of adults aged 20 and over are either overweight or obese. This number has grown a lot over the past 40 years. By 2035, the World Obesity Federation predicts that 51% of people worldwide will be overweight or obese, with many of these changes expected in low or middle-income countries.