What is Obesity?

What is Obesity?

Obesity is a chronic, relapsing, inflammatory disease that requires lifelong medical care.1-3 An adult with a BMI >30 is considered to have obesity.4,5

Obesity affects almost every organ in your body and increases your risk of developing serious health problems, including type 2 diabetes, high blood pressure, stroke, liver and kidney disease, sleep apnoea, and osteoarthritis.6-8

Picture of BMI chart
Calculate Your Body Mass Index (BMI)

BMI calculates the relationship between weight and height. It can measure obesity and indicate risk for developing weight-related health problems. 4,6 

Diagram of three arrows comparing weight loss between lifstyle changes, medication and weight loss surgery.

Why Diet and Exercise May Not Always Work

Obesity is influenced by many factors.1,4,9,10 Changes in environment, stress levels, sleep, or diet can trigger your body to store fat and gain weight.4,5,10,11 Diet and exercise can lead to weight loss, but it can be hard to keep it off.2,11,12 Losing weight through diet and exercise can trigger your body to increase hunger, decrease feelings of fullness, and slow down metabolism – like your body is fighting weight loss.2,11-14

Learn More

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Want to Know More?

Ready to take the next step in your weight loss journey? Read our resource on talking to your doctor about weight loss surgery or visit our Weight Loss Support page for more options.

Diagram of three arrows comparing weight loss between lifstyle changes, medication and weight loss surgery.

Why is Weight Loss Surgery Effective?

Ready to know more about weight loss surgery? Our Weight Loss Surgery page can answer some of your questions and help you to understand if weight loss surgery may be right for you. You should always talk to your doctor when considering surgery. Read more about Weight Loss Surgery as an Effective Treatment for Obesity


1.    Bray GA, et al. Obes Rev. 2017;18(7):715-723. 

2.    Papamargaritis D, le Roux CW. Nutrients. 2021;13(3):762. 

3.    Royal Australian College of General Practitioners. Obesity prevention and management position statement. February 2019. Available: https://www.racgp.org.au/FSDEDEV/media/documents/RACGP/Position%20statements/Obesity-prevention-and-management.pdf (accessed May 2021).

4.    National Health and Medical Research Council. Clinical practice guidelines for the management of overweight and obesity in adults, adolescents and children in Australia. 2013. Melbourne: National Health and Medical Research Council. 

5.    Schwartz MW, et al. Endocr Rev. 2017;38(4):267-296. 

6.    Bray GA, et al. Endocr Rev. 2018;39(2):79-132. 

7.    Poirier P, et al. Circulation. 2006;113(6):898-918. 

8.    Garvey WT, et al. Endocr Pract. 2016;22 Suppl 3:1-203. 

9.    Caterson ID, et al. Diabetes Obes Metab. 2019;21(8):1914-1924.

10.    Das B, Khan OA. Int J Surg. 2019;68:114-116. 

11.    Sumithran P, Proietto J. Clin Sci (Lond). 2013;124(4):231-241. 

12.    Al-Najim W, et al. Physiol Rev. 2018;98(3):1113-1141. 

13.    Pucci A, Batterham RL. J Endocrinol Invest. 2019;42(2):117-128. 

14.    Fothergill E, et al. Obesity (Silver Spring). 2016;24(8):1612-1619.

There are risks with any surgery, such as adverse reactions to medications, problems with anaesthesia, problems breathing, bleeding, blood clots, inadvertent injury to nearby organs and blood vessels, even death. Bariatric surgery has its own risks, including failure to lose weight, nutritional or vitamin deficiencies and weight regain. Patients should consult their doctor to determine whether this procedure is appropriate for their condition. Alternative options to surgery include a healthy energy-controlled diet and physical activity.

This information is intended for residents of Australia only.

The information on this site is for educational purposes only and is not medical advice. Always talk to your doctor before you make decisions about your health.

© 2021 Johnson & Johnson Medical Pty Ltd. This site is published by Johnson & Johnson Medical Pty Ltd which is solely responsible for its contents. Ethicon is a business unit of Johnson & Johnson Medical Pty Ltd. 1-5 Khartoum Road, North Ryde, NSW 2113, ABN 85 000 160 403.