Obesity: A Complex Chronic Disease, Not a Lack of Willpower
Over a billion obese people worldwide in 2022
Dr. Marc Durand
Endocrinologist
In simple terms
Obesity is a multifactorial disease involving genetics, environment, and neurobiology. New drug treatments are changing the game.
Obesity, a global epidemic
According to health authorities, over a billion people worldwide were living with obesity in 2022, including 159 million children and adolescents. Obesity is defined by a body mass index (BMI) greater than or equal to 30 kg/m². It is not a lifestyle choice, but a complex chronic disease.
Multiple causes
Genetics explain 40-70% of susceptibility to obesity. Environmental factors — ultra-processed foods, sedentary lifestyle, stress, lack of sleep, endocrine disruptors — interact with this predisposition. The brain regulates body weight around a "set point" that it defends after each weight loss.
Health complications
Obesity increases the risk of type 2 diabetes (x7), cardiovascular diseases, sleep apnea, hepatic steatosis (fatty liver), depression, and certain cancers (breast, colon, kidney). It reduces life expectancy by 5 to 20 years depending on severity.
Current treatments
GLP-1 agonists (semaglutide, tirzepatide) represent a therapeutic revolution with weight losses of 15 to 25%. Bariatric surgery remains the most effective option for severe obesity. Nutritional and psychological support is essential in all cases.
The words explained
Medical terms used above, in everyday language.
- Chronic
- A problem that lasts a long time, usually more than three months, and often comes back.
- BMI
- A simple number from your weight and height used as a rough guide to healthy weight.
- Cardiovascular
- Related to the heart and blood vessels.
- Genetic
- Passed down in your family through your genes.
When should you see a doctor?
- Your symptoms last more than a few weeks or keep coming back.
- They get worse quickly, or stop you doing everyday things.
- You notice sudden pain, breathing trouble, fainting or bleeding — seek urgent care.
- You already take medication and want to change anything about it.
This article explains general health information. It does not replace advice from your own doctor.
Frequently asked questions
- What is Obesity: A Complex Chronic Disease, Not a Lack of Willpower?
- Obesity is a multifactorial disease involving genetics, environment, and neurobiology. New drug treatments are changing the game.
- What are the main symptoms or signs of Obesity: A Complex Chronic Disease, Not a Lack of Willpower?
- Common signs vary from person to person. The article above lists the symptoms to watch for, how they progress, and when they need medical attention.
- When should you see a doctor for Obesity: A Complex Chronic Disease, Not a Lack of Willpower?
- See a doctor if symptoms last more than a few weeks, get worse quickly, stop you doing everyday things, or if you notice sudden pain, breathing trouble, fainting or bleeding.
Related health topics
Nutrition
Sustainable weight loss without dieting
Environment, protein, sleep and consistency outperform willpower.
Diabetes & Endocrinology
Type 1 Diabetes: A Lifelong Autoimmune Disease
Type 1 diabetes accounts for 5-10% of all diabetes and most often appears in children and young adults.
Diabetes & Endocrinology
Type 2 Diabetes: Prevention Is Possible
Type 2 diabetes affects over 460 million adults. Modest weight loss reduces incidence by more than half.
Diabetes & Endocrinology
Hypothyroidism: Common, Treatable, Often Missed
An underactive thyroid affects 1-5% of adults. Symptoms are subtle, but treatment is simple and effective.
Diabetes & Endocrinology
Hyperthyroidism: When the Thyroid Races
Graves' disease is the most common cause of an overactive thyroid in adults under 50.
Diabetes & Endocrinology
Polycystic Ovary Syndrome: Far More Than Cysts
PCOS combines irregular periods, hyperandrogenism and metabolic features. Early diagnosis improves long-term outcomes.