What You Should Know About Obesity: Types and Causes

Obesity is a complex chronic medical condition that affects millions of people and can significantly impact overall health and quality of life.

Researchers now understand that weight gain is influenced by many factors, including genetics, hormones, metabolism, stress, sleep, medications, and lifestyle habits. Because of this, obesity is no longer viewed as a condition that can always be addressed through diet and exercise alone.

As our understanding of obesity has evolved, so have the available treatment options. Today, individuals may benefit from a combination of lifestyle interventions, medical therapies, behavioral support, and newer medications such as GLP-1 receptor agonists, which can help regulate appetite and support weight management when medically appropriate.

This article explains what obesity is, its different classes, common symptoms, and the many factors that can contribute to weight gain, all in a clear, supportive, and judgment-free way.

Obesity is a treatable condition. With the right medical care and lifestyle support, many people improve their health and quality of life.

What Is Obesity?

Obesity is a chronic medical condition characterized by an excessive accumulation of adipose tissue, more commonly known as body fat, that can negatively affect health. It is not simply about appearance or a number on the scale. Rather, it involves how excess body weight and adiposity influence the body's organs, metabolism, and overall well-being. When adipose tissue accumulates beyond healthy levels, the risk of developing a variety of health conditions increases.

Body Mass Index (BMI) is a common tool used to estimate whether a person's weight falls within a healthy range based on height and weight. While it is not a direct measure of body composition, BMI helps healthcare providers identify obesity and assess related health risks.

Today, obesity is recognized as a chronic medical condition that often requires more than diet and exercise alone. Researchers have learned that hormones, genetics, metabolism, and brain signals that regulate hunger all play a role in body weight. This growing understanding has led to new treatment options, including GLP-1 receptor agonists, which help regulate appetite and increase feelings of fullness.

For some individuals, these medications can be an effective part of a comprehensive weight management plan alongside healthy lifestyle changes.

Classes of Obesity

Obesity is divided into three main classes based on BMI numbers. These classes help doctors understand the severity of the condition and the potential health risks involved.

Class 1 Obesity

BMI between 30 and 34.9

This level indicates a moderate increase in body weight and adiposity. People in this class may begin to experience health concerns such as high blood pressure or early signs of diabetes.

Class 2 Obesity

BMI between 35 and 39.9

This class reflects a greater accumulation of adipose tissue and an increased risk for serious health conditions such as heart disease, sleep apnea, and type 2 diabetes.

Class 3 Obesity

BMI of 40 or higher

Sometimes called severe or morbid obesity, this class carries the highest risk for life-threatening conditions. It often requires more intensive medical support and lifestyle changes.

Understanding these classes helps patients and healthcare providers work together to create personalized care plans.

Symptoms of Obesity

Obesity can affect the body in many ways. Some common symptoms include:

• Fatigue

Carrying extra weight can tire your body more quickly, making everyday tasks feel harder.

• Joint Pain

Excess weight puts pressure on joints, especially knees and hips, leading to discomfort or arthritis.

• Shortness of Breath

An increased accumulation of adipose tissue around the chest and abdomen can make breathing more difficult, especially during physical activity or exertion.

• Sleep Issues

Obesity increases the risk of sleep apnea, a condition where breathing stops briefly during sleep, causing poor rest and daytime tiredness.

• Reduced Mobility

Moving around can become more challenging, which may limit physical activity and contribute to a cycle of weight gain.

If you notice these symptoms, it’s important to discuss them with a healthcare provider who can help identify the underlying causes and suggest appropriate treatments.

Causes of Obesity

Obesity results from a combination of factors, not just overeating or lack of exercise. Understanding these causes can reduce stigma and support better care.

• Genetics

Some people inherit genes that affect how their bodies store fat and use energy. This can make them more prone to becoming obese, even with healthy habits.

• Hormones

Hormonal imbalances, such as those involving thyroid function or insulin, can influence weight gain.

• Lifestyle

Diet and physical activity play a big role. High-calorie foods, sugary drinks, and sedentary habits contribute to excess weight.

• Stress

Chronic stress can contribute to emotional eating and metabolic changes that may lead to gradual weight gain over time.

• Medications

Certain drugs, including some antidepressants and steroids, may cause weight gain as a side effect.

• Menopause-Related Changes

Hormonal changes during menopause can slow metabolism and contribute to shifts in body composition, including increased abdominal accumulation.

Each person’s situation is unique, and often several of these factors interact to cause obesity.

Moving Forward With Support

Obesity is a treatable condition. With the right medical care and lifestyle support, many people improve their health and quality of life.

Treatment may include:

• Nutritional counseling

• Physical activity plans tailored to individual ability

• Medical therapies or medications, including GLP-1 receptor agonists for eligible patients

• Behavioral support to manage stress and emotional eating

• In some cases, surgical options

If you or a loved one is living with obesity, remember that help is available. Working with healthcare professionals can guide you toward healthier habits and better well-being without judgment.

How LifeviewMD Can Help

At LifeviewMD, obesity is approached as a medical condition with multiple contributing factors—not simply a matter of willpower. Care is personalized to each patient, focusing on identifying and addressing the underlying causes of weight gain, including metabolism, hormones, lifestyle patterns, stress, sleep, and other health conditions.

Dr. Elisabeth Aponte is a fellowship-trained glaucoma specialist, board-certified ophthalmologist, cataract surgeon, and Board-Certified in Lifestyle Medicine. She also has focused training in obesity medicine and women’s health-related conditions, including perimenopause, menopause, and dry eye disease. Her multidisciplinary background allows her to take a whole-person approach to care that connects vision, metabolic health, and hormonal wellness.

Depending on your needs, LifeviewMD may offer metabolic and health evaluation, nutrition and activity guidance, hormone-related assessment, and structured weight management support.