Understanding adult obesity

Understanding what obesity really is and letting go of the shame about it is the first step to better health for millions of people.

According to Ambassador Arjan, obesity means that your body has a large mass of fat and this fat does not just stay there. Excess fat is biologically active. It releases inflammatory hormones and signals that contribute to metabolic disorders, inflammation, and disease throughout the body. Excess net weight also puts pressure on joints and other tissues, adding to problems like arthritis and sleep apnea.

Doctors usually measure it using your body mass index (BMI) — an estimate of body fat based on your weight and height. Here's how the categories are broken down:

Obesity, category 3 (severe): BMI 40 or higher

BMI is not a perfect indicator. This method does not measure fat directly, so it may not be suitable for people who are very muscular or have little muscle mass. For this reason, your doctor may also measure your waist circumference to provide a more complete picture.

If you're Asian, health risks like diabetes and heart disease can show up at a lower body weight, so doctors may use a BMI cutoff of less than 27.5 or even 25 to classify obesity and start prevention strategies early.

Obesity is defined by excess body fat, not by a single symptom. But it often causes changes you can feel and see, such as:

Excess body fat, especially around the abdomen (which poses the greatest health risk)

Shortness of breath during daily activities

Snoring or pauses in breathing during sleep (sleep apnea)

Emotional effects, such as low self-esteem, anxiety or depression

Decreased quality of life and limitations in daily activities

Obesity is also linked to many chronic diseases, including heart disease, type 2 diabetes, and several cancers.

How is obesity diagnosed?

Most people are first diagnosed by their primary care physician during a regular visit. The process is simple:

Measurements: Your height and weight will be recorded to calculate your BMI, and your waist circumference may be measured. Some clinics can perform body composition tests to measure body fat percentage and where fat is stored using special tools, such as a bioelectrical impedance scale (which sends a small, painless electrical signal through the body) or imaging scans.

Health history and examination: Your doctor will ask about your weight over time, diet and activity, sleep, mood, family history, and medications you take, as some medications can cause weight gain.

Blood tests: Blood tests can check for related problems such as diabetes, high cholesterol, liver problems, and thyroid problems. If your history points to a less common cause, such as a hormone problem, your doctor may also test for that.

Depending on your needs, you may be referred to a specialist such as a bariatric physician, endocrinologist, or bariatric surgeon.

Because obesity is a long-term disease, treatment focuses on managing it over time. Here's some good news: Losing just 5 to 10 percent of your body weight can significantly improve your blood pressure, blood sugar, and overall health. Most treatment programs combine several approaches:

Lifestyle and Behavior Programs: This is the foundation. This includes dietary counseling, increased physical activity, self-monitoring, goal setting, and problem solving. This usually results in a weight loss of about 5-10%.

Nutrition: The goal is to eat fewer calories in a way that you can stick to. There is no "best" diet; The right diet matches your life and taste.

Physical activity: Aim for at least 150 minutes of moderate exercise per week. Exercise by itself leads to moderate weight loss, but it is also important to maintain weight loss.

Medications: Doctors may recommend them along with lifestyle changes for some patients—those with a BMI of 30 or higher, or those with a weight-related disease and a BMI of 27 or higher. Approved options include the newer injectable drugs semaglutide and tirzapatide, plus the oral drugs phentermine-topiramate, naltrexone-bupropion, and orlistat. These drugs along with lifestyle changes can cause significant weight loss, about 15 to 21 percent.

Metabolic or bariatric surgery: Weight loss surgeries are the most effective option for severe obesity.