WHO’s Obesity and Overweight Fact Sheet Highlights Over 1 Billion People Are Obese: The Hidden Drivers Behind the Global Surge

Obesity is more than a cosmetic concern. It is a chronic disease that can affect overall health and increase the risk of several serious conditions, including type 2 diabetes, heart disease, and certain cancers. According to the World Health Organization (WHO), around 1.1 billion people worldwide were living with obesity in 2024, highlighting the growing burden of the condition.

Obesity can affect people of all ages and backgrounds. Although diet and physical activity play important roles, weight gain is also influenced by genetics, biological processes, social conditions, and the surrounding environment. Understanding these factors is essential for effective prevention and treatment.

What Is Overweight and Obesity?

Overweight and obesity refer to an abnormal or excessive accumulation of body fat that may harm health.

The WHO uses body mass index (BMI) as a screening tool to assess weight status in adults. It is calculated by dividing a person's weight in kilograms by their height in metres squared.

According to WHO criteria:

• Overweight: BMI of 25 or above
• Obesity: BMI of 30 or above

BMI is a screening measure rather than a direct measurement of body fat. A healthcare professional may also consider waist circumference, medical history, and other health indicators to assess an individual's risk.

For children and adolescents, BMI must be interpreted according to age and sex using appropriate growth charts.

How Common Is Obesity Worldwide?

The WHO's 2024 estimates show the scale of the problem:

• Around 2.6 billion adults aged 18 and above were overweight, representing 45% of adults worldwide.
• Approximately 940 million adults were living with obesity.
• About 35 million children under five were overweight.
• Around 400 million children and adolescents aged 5-19 were overweight, including 170 million living with obesity.

The prevalence of obesity among adults worldwide has more than doubled since 1990. The figures show that obesity is no longer confined to high-income countries and has become a major global public health challenge.

Causes of Obesity

Obesity develops through complex interactions between biological, environmental, social, and behavioural factors. It cannot be explained simply by eating too much or exercising too little.

Unhealthy dietary patterns

Regularly consuming foods high in calories, sugar, salt, and unhealthy fats can contribute to weight gain, particularly when energy intake exceeds the body's needs. Sugary drinks and energy-dense, nutrient-poor foods can make it harder to maintain a healthy weight.

Also Read: Pregnancy Diet Is Crucial In Preventing Childhood Obesity In Kids

Physical inactivity
Spending long periods sitting, limited opportunities for exercise, and reduced everyday movement can contribute to excess weight gain. Urban environments that lack safe walking spaces may also restrict physical activity.

Genetic and biological factors
Genetics can influence appetite, metabolism, fat storage, and how the body regulates hunger and fullness. Hormonal and metabolic processes also affect an individual's susceptibility to obesity.

Social and environmental influences
The availability and affordability of nutritious food, food marketing, working patterns, sleep habits, and access to recreational spaces can influence weight. These factors may make healthy choices more difficult for some people.

Health Risks of Obesity

Obesity can affect several organs and body systems. It increases the risk of:

• Type 2 diabetes: Excess body fat can contribute to insulin resistance, making it harder to regulate blood sugar.
• Heart disease and stroke: Obesity is associated with high blood pressure and other cardiovascular risk factors.
• Certain cancers: Obesity is linked to an increased risk of several cancers.
• Liver and kidney disease: Excess body fat can contribute to metabolic dysfunction and organ damage.
• Reduced physical and mental well-being: Obesity may affect mobility, quality of life, and emotional health. People may also experience weight-related stigma, discrimination, or bullying.

Obesity during childhood and adolescence can have lasting consequences, particularly when it continues into adulthood. Early identification and appropriate support can help reduce future health risks.

Also Read: Obesity and Fatty Liver: Understanding the Link, Risks and Management

How Can Obesity Be Prevented and Managed?

The WHO states that overweight and obesity are largely preventable and manageable. Here are some effective tips:

• Eat a balanced diet: Include vegetables, fruits, pulses, whole grains and nuts. Limit sugary drinks and foods high in sugar, salt, and unhealthy fats.
• Stay physically active: Make regular movement part of everyday life. Walking, cycling, dancing and other activities suited to your fitness level can help.
• Prioritise sleep: Adequate sleep and emotional well-being are important parts of maintaining overall health.
• Seek professional guidance: A healthcare professional can assess weight-related health risks and develop an individualised management plan. Depending on a person's needs, treatment may include nutritional counselling, behavioural support, medicines or metabolic and bariatric surgery.

Final Word

Obesity is a complex chronic disease influenced by more than food intake and exercise alone. Recognising its causes, identifying health risks early and providing appropriate long-term care can improve outcomes. A balanced diet, regular physical activity, adequate sleep, and professional support can all contribute to healthier weight management.