Obesity: Causes, Health Risks, Diagnosis and Treatment Options

What Is Obesity?

Obesity is a chronic medical condition in which excess body fat may increase the risk of health problems.

It develops through a complex interaction of biological, genetic, environmental and behavioral factors. Obesity should not be viewed simply as a lack of willpower or self-control.

Treatment focuses not only on reducing body weight but also on improving overall health, mobility, metabolic health and quality of life.

How Is Obesity Diagnosed?

One of the most commonly used screening tools is body mass index, or BMI.

For most adults:

• BMI 18.5–24.9 is considered within the healthy range
• BMI 25–29.9 is classified as overweight
• BMI 30 or higher is classified as obesity

However, BMI does not directly measure body fat and does not tell the complete story.

Doctors may also consider waist circumference, blood pressure, blood tests, medical history, body composition and obesity-related conditions when assessing a patient.

What Causes Obesity?

There is rarely one single cause.

Factors that may contribute include:

• Genetics and family history
• High-calorie food and drink intake
• Low levels of physical activity
• Poor or insufficient sleep
• Stress
• Certain medications
• Hormonal or metabolic conditions
• Pregnancy-related weight changes
• Psychological and eating disorders
• Environmental and socioeconomic factors

Conditions such as hypothyroidism, Cushing syndrome and polycystic ovary syndrome may also contribute to weight gain in some patients.

A proper medical assessment can help identify factors that should be addressed as part of treatment.

What Health Problems Are Associated With Obesity?

Obesity can increase the risk of several chronic diseases.

These may include:

• Type 2 diabetes
• High blood pressure
• High cholesterol and triglycerides
• Heart disease
• Stroke
• Sleep apnea
• Fatty liver disease
• Osteoarthritis and joint problems
• Kidney disease
• Gallbladder disease
• Certain types of cancer

The level of risk differs between individuals and generally increases with the amount and duration of excess body fat.

How Is Obesity Treated?

Treatment should be individualized.

A comprehensive program may include nutritional changes, physical activity, behavioral support, medication or metabolic and bariatric surgery.

The goal is not always to reach a particular number on the scale. Even moderate weight loss can improve blood pressure, blood sugar and other obesity-related health problems.

Nutrition and Physical Activity

A sustainable eating plan is usually more effective than extreme or short-term dieting.

The aim is to create eating habits that provide appropriate nutrition while reducing excess calorie intake.

Regular physical activity is also important.

Exercise can support weight management while improving cardiovascular health, muscle strength, mobility and mental well-being.

The appropriate level of activity depends on the patient's health and physical ability.

Weight-Loss Medication

Prescription weight-management medicines may be considered when lifestyle treatment alone has not produced sufficient results or when obesity is causing significant health risks.

Different medications work in different ways. Some reduce appetite, increase feelings of fullness or affect how the body processes food.

Medication should be prescribed and monitored by a doctor.

These treatments generally work best when combined with long-term nutritional, physical activity and behavioral changes rather than being used alone.

When Is Bariatric Surgery Considered?

Metabolic and bariatric surgery may be considered for selected patients with obesity, particularly when significant obesity-related health conditions are present or other treatments have not been sufficient.

Common procedures include:

• Sleeve gastrectomy
• Gastric bypass

These operations can help patients lose substantial weight and may improve conditions such as type 2 diabetes, high blood pressure and sleep apnea.

However, surgery requires careful evaluation before treatment and long-term follow-up afterward.

What Happens Before Bariatric Surgery?

Patients usually undergo a multidisciplinary assessment.

This may include:

• Blood tests
• Heart and lung evaluation
• Nutritional assessment
• Review of previous weight-loss attempts
• Evaluation of diabetes and other medical conditions
• Psychological or behavioral assessment when appropriate

The team determines whether surgery is suitable and which procedure may be most appropriate.

Life After Bariatric Surgery

Bariatric surgery is not the end of obesity treatment.

Patients need long-term changes in eating habits and regular medical follow-up.

Some procedures can increase the risk of vitamin and mineral deficiencies, so supplements and periodic blood tests may be required.

Regular physical activity and ongoing nutritional support are also important for maintaining results.

A Long-Term Approach to Obesity

Obesity treatment works best when it is viewed as long-term medical care rather than a short diet or temporary program.

Some patients may benefit primarily from lifestyle treatment, while others may need medication, bariatric surgery or a combination of approaches.

The right plan depends on BMI, waist circumference, existing medical conditions, previous treatments, medications, lifestyle and personal goals.

Evaluation by a physician or multidisciplinary weight-management team can help identify the safest and most effective treatment strategy for each patient.