What health conditions can obesity lead to? A guide to diabetes, cardiovascular disease and cancer risk!
Health2026-08-24
8 Mins Read
Obesity is more than a matter of body weight or appearance. It is associated with an increased risk of a range of health conditions, including diabetes, high blood pressure, heart disease, fatty liver disease and certain types of cancer. The World Health Organization classifies obesity as a chronic, relapsing disease that requires long-term management.
In recent years, weight-loss injections and other rapid weight-loss methods have attracted significant attention. However, beyond the pursuit of quick results, it is equally important to understand the long-term impact obesity can have on overall health. Excess body fat not only increases the risk of chronic disease but may also lead to substantial medical expenses over time. What health conditions can obesity lead to? How can you tell if you are obese? And what steps can you take to reduce the associated health risks? In this article, we'll take a closer look at the answers to these questions.
Quick answers about obesity
Q1: What is considered obesity?
Q2: What health conditions can obesity lead to?
Q3: Does obesity always lead to illness?
Q4: How can obesity-related diseases be prevented?
What is considered obesity?
One of the most widely used ways to determine whether your weight falls within a healthy range is by calculating your Body Mass Index (BMI).
BMI formula: BMI = Weight (kg) ÷ Height (m)²
According to the Hong Kong Department of Health, the BMI classification for Chinese adults is as follows:
Weight status | BMI (kg/m²) |
Underweight | |
Underweight | Below 18.5 |
Healthy weight | |
Healthy weight | 18.5 to 22.9 |
Overweight | |
Overweight | 23.0 to 24.9 |
Obese | |
Obese | 25.0 or above |
BMI is a useful screening tool, but it is not the only measure of obesity. Waist circumference is also an important indicator of health risk. Men with a waist circumference of 90 cm or above and women with a waist circumference of 80 cm or above are considered to have central obesity, which indicates excess abdominal fat and is closely associated with an increased risk of metabolic diseases.
How common is obesity in Hong Kong?
According to the Department of Health's Population Health Survey 2020-22:
- 32.6% of adults were classified as obese
- 22.0% were classified as overweight
- More than half of all adults were above a healthy weight range¹˒²
- The prevalence of central obesity reached 37.8%¹˒²
Perhaps even more concerning, a survey conducted by the Hong Kong Society of Obesity found that nearly 70% of respondents did not recognise obesity as a disease³.
The World Health Organization classifies obesity as a chronic, relapsing disease. Its development is influenced by a complex interplay of factors, including genetics, hormones, dietary habits, living environments and socioeconomic conditions. In other words, obesity is not simply a matter of body weight or appearance. It is a long-term health condition that requires ongoing management.
What health conditions are linked to obesity?
Obesity is associated with a wide range of chronic health conditions, including type 2 diabetes, high blood pressure, cardiovascular disease, fatty liver disease and several types of cancer. A key underlying mechanism is chronic low-grade inflammation triggered by excess body fat, which can affect almost every organ system in the body.
Obesity is often described as a major contributor to chronic disease because excess fat tissue can trigger a series of physiological changes that negatively affect long-term health.
1. Type 2 diabetes
Obesity is one of the most important risk factors for type 2 diabetes. When excess fat accumulates in the body, cells become less responsive to insulin, leading to a condition known as insulin resistance. To keep blood glucose levels under control, the pancreas has to produce increasing amounts of insulin. Over time, this can place excessive strain on the pancreas, making blood sugar more difficult to regulate and increasing the risk of developing type 2 diabetes.
2. High blood pressure and cardiovascular disease
Obesity places additional strain on the heart and circulatory system. Excess body fat can contribute to raised blood pressure and accelerate the development of atherosclerosis, or hardening of the arteries, increasing the risk of:
- High blood pressure
- Coronary heart disease
- Heart failure
- Stroke
As a result, maintaining a healthy weight is an important part of protecting long-term cardiovascular health.
3. Fatty liver disease and metabolic syndrome
Excess fat can accumulate in the liver, leading to non-alcoholic fatty liver disease (NAFLD). If left unmanaged, the condition may progress to more serious liver complications, including:
- Non-alcoholic steatohepatitis (NASH)
- Liver fibrosis
- Liver cirrhosis
Fatty liver disease often occurs alongside other metabolic conditions, such as type 2 diabetes, high blood pressure and abnormal cholesterol levels. For this reason, it is considered an important sign of underlying metabolic dysfunction.
4. Increased risk of certain cancers
Many people are aware of the link between obesity and diabetes, but fewer realise that obesity is also associated with an increased risk of several types of cancer. Research suggests that obesity is linked to a higher risk of cancers including, but not limited to:
- Breast cancer
- Colorectal cancer
- Endometrial cancer
- Oesophageal cancer
- Kidney cancer
Chronic inflammation and hormonal changes associated with obesity are believed to be among the key mechanisms contributing to this increased cancer risk.
Why does obesity increase the risk of chronic disease? Understanding the role of chronic inflammation
One of the key links between obesity and chronic disease is a process known as chronic low-grade inflammation.
Under normal circumstances, fat tissue plays important roles in storing energy and regulating hormones. However, when excess body fat accumulates, fat cells become enlarged and can trigger the immune system to release inflammatory substances. Over time, this persistent inflammatory response may contribute to a range of health problems, including:
- Insulin resistance
- Hardening of the arteries (atherosclerosis)
- Fatty liver disease
- Metabolic dysfunction
In simple terms, obesity is more than just an increase in body weight. It can place the body in a prolonged state of low-grade inflammation, which gradually raises the risk of developing chronic diseases over time.
Three key steps to reducing the health risks associated with obesity
Key step 1: Adopt healthy eating habits
The goal is not extreme dieting, but maintaining a healthy eating pattern over the long term. Consider the following principles:
- Cut back on refined carbohydrates and added sugars: Reduce your intake of white rice, white bread, sugary drinks and desserts. Choose whole grains such as brown rice and oats instead.
- Increase fibre and high-quality protein intake: Eat more vegetables, fruit (particularly lower-sugar options), lean meat, skinless poultry, fish and seafood.
- Manage fat intake: Limit fried foods and processed meats, and opt for cooking methods such as steaming, boiling or serving foods cold where appropriate.
- Maintain regular 3 meals: Eat balanced meals throughout the day and avoid overeating or binge eating.
Key step 2: Stay physically active
Exercise does more than burn calories. It can also improve insulin sensitivity, lower blood pressure and support healthier blood lipid levels.
Recommendations include:
- Aim for at least 150 minutes of moderate-intensity aerobic activity each week, such as brisk walking, jogging, swimming or cycling.
- Include strength training as part of your routine, as building muscle mass can help increase your resting metabolic rate.
- Reduce prolonged sitting time by standing up, stretching or moving around at least once every hour.
Key step 3: Have regular health check-ups
Prevention is better than cure, and regular monitoring can help identify potential health issues at an early stage.
Consider keeping track of:
- Body weight
- Body Mass Index (BMI)
- Waist circumference
- Blood glucose levels
- Blood lipid levels
- Liver function
If any of these indicators fall outside the healthy range, it is advisable to seek guidance from a healthcare professional as early as possible.
How can health insurance help when chronic disease develops?
Even with proactive prevention, some people may still develop obesity-related chronic conditions due to genetic factors or other underlying causes. Diseases such as diabetes, heart disease, stroke and cancer often require long-term treatment and management, which can result in substantial medical expenses.
AXA offers a range of health insurance solutions covering areas such as hospitalisation, surgery, specialist consultations and cancer treatment. Some plans are also designed to address the protection needs of individuals living with diabetes and chronic conditions known as the “3-Highs”. Before purchasing any health insurance plan, it is important to understand the scope of cover, waiting periods and exclusions, and to choose a plan that suits your health needs and budget.
Frequently asked questions (FAQs)
Q1: What BMI is considered obese?
Q2: If my waist circumference is normal, does that mean I have no obesity-related health risks?
Q3: Does obesity always lead to diabetes?
Q4: Can losing weight reduce the risk of chronic disease?
Addressing obesity starts today
Obesity is not simply a matter of appearance. It is a health risk that deserves early attention and long-term management. Through a balanced diet, regular physical activity and routine health screenings, many obesity-related conditions may be prevented or their onset delayed.
By adopting healthier lifestyle habits early and putting appropriate health protection in place, you can be better prepared to manage future health challenges with greater confidence and peace of mind.
- Centre for Health Protection, Department of Health, Hong Kong SAR Government (2024). Obesity. Retrieved from: https://www.chp.gov.hk/en/healthtopics/content/25/8802.html
- Centre for Health Protection, Department of Health, Hong Kong SAR Government (2023). Non-Communicable Diseases Watch: Obesity (p. 4). Retrieved from: https://www.chp.gov.hk/files/pdf/ncd_watch_june_2023_chin.pdf (Chinese only)
- Ta Kung Pao (2026). Nearly 70% of respondents do not recognise obesity as a disease, experts urge early weight management. Retrieved from: https://epaper.tkww.hk/a/202601/09/AP69601292e4b0eb9195c1a59a.html (Chinese only)
- Abdullah, A. et al. (2010) “The magnitude of association between overweight and obesity and the risk of diabetes: a meta-analysis of prospective cohort studies”, Diabetes Research and Clinical Practice, 89(3), pp. 309-319
- Lu, Y., Hajifathalian, K., Ezzati, M., Woodward, M., Rimm, E.B., & Danaei, G. (2014). Metabolic mediators of the effects of body-mass index, overweight, and obesity on coronary heart disease and stroke: a pooled analysis of 97 prospective cohorts with 1·8 million participants. The Lancet, 383(9921), 970-983.
- Kenchaiah, S., Evans, J.C., Levy, D., Wilson, P.W., Benjamin, E.J., Larson, M.G., ... & Vasan, R.S. (2002). Obesity and the risk of heart failure. New England Journal of Medicine, 347(5), 305-313.
- Li, L., Liu, D. W., Yan, H. Y., Wang, Z. Y., Zhao, S. H., & Wang, B. (2016). Obesity is an independent risk factor for non-alcoholic fatty liver disease: Evidence from a meta-analysis of 21 cohort studies. Obesity Reviews, 17(6), 510–519.
- 周蒙, 薄濤, 范修德, 等. 代謝相關脂肪性肝病：全身代謝性紊亂的核心樞紐之一[J]. 臨床肝膽病雜誌, 2025, 41(9): 1725-1728. DOI: 10.12449/JCH250902.
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