Take the first step and find the doctor for you
Finding a doctor who understands the complexities of obesity is essential. Use our tool to find a doctor near you.
Your result: Obesity II
Having a BMI of 30 and above may mean that you have obesity.
Recommendation
Having a BMI of 30 and above may mean that you have obesity and may be at risk of other weight-related complications. It is recommended that you consult with your doctor or other healthcare providers trained in obesity management.
The goal of managing and treating obesity is not simply to lose weight, but instead to improve health and lower the risks of other health complications.
There are various scientifically backed treatment options for obesity that may be suggested for people in this category.
Doctors make recommendations depending on the specific needs, current health status and whether there are any weight-related complications.
Treatments can include:
- Healthy eating
- Increased physical activity
- Behavioural therapy
- Meal replacements / low energy diets
- Weight management medications
- Bariatric surgery*
You can learn more about weight management options here.
*Bariatric surgery is considered for adults with a BMI of 40 or above or adults with a BMI of over 35 who also have weight-related complications.
| Classification | BMI |
| Underweight | Below 18.5 |
| Normal weight | 18.5–24.9 |
| Overweight | 25–29.9 |
| Obesity | 30 and above |
| Class I | 30–34.9 |
| Class II | 35–39.9 |
| Class III | 40 and above |
This BMI calculator is for adults 20 years or older. Talk to your doctor about your BMI if you're under the age of 20.1
It's important to know that this classification can vary in certain ethnic groups, such as Indigenous Peoples, South Asians, Chinese and other populations. Always check with your healthcare professional about the suitability of this BMI classification based on your own circumstances.1
Tips and advice
This is just for disease awareness purposes. Please speak with your doctor or healthcare team if you have any questions and follow their advice.
A healthy lifestyle is recommended for everybody. However if your BMI shows that you're overweight or have obesity at any point, it may be time to make changes so that you can be at a healthier weight. Many things can affect your weight, so you can also try to manage it in different ways. Click on an item below to see what you can do to make a change today.
Nutrition
There is no perfect diet for losing weight. But there are scientifically backed ways of eating that can help you manage weight and prevent the weight from coming back. Focus on managing a healthy weight instead of going to extremes in limiting how much you eat. Here are some examples of diets that may help:2
- Mediterranean diet
- High fibre diet
- Vegetarian diet
Learn more about starting healthier ways of eating and choosing foods for better weight control here.
Mental health
There are many reasons why we gain and manage weight and sometimes, they have to do with how we feel.
Some people use food to cope with difficult situations and their feelings. Eating to feel better is called emotional eating — and it's the reason why we sometimes need psychological support instead of diet advice.3
Stress can also change the way that you eat and put you at more risk of developing overweight or obesity. Learning to manage the stress in your life is one strategy you can also include in your weight management plan.3
Activity
Regular exercise is very important for managing your weight.4 To make sure that your weight loss program is as effective as possible, consider adding aerobic and resistance exercises to your routine. You should also move more in general.
Find tips for getting a good start on a new exercise program here.
Sleep
Getting too little sleep can affect your hormones, which can then affect how and what you eat. When you sleep better, you're better able to make healthy choices and resist tempting foods. Try these tips to improve your sleeping habits:5
- Create healthy routines around sleeping
- Relax before going to bed
- Make your bedroom a great place to sleep
Your health risk
Living with overweight or obesity is associated with an increased risk of mortality and other diseases or conditions. Generally, the higher your BMI, the greater the chance of developing other chronic weight-related diseases, including:6-23
- Type II diabetes
- High blood sugar levels
- High cholesterol levels
- High blood pressure
- Infertility
- Depression and anxiety
- Coronary heart disease
- Dyslipidaemia
- Liver conditions like metabolic dysfunction-associated steatohepatitis (MASH) / metabolic dysfunction-associated fatty liver disease (MAFLD)
- Gastro-oesophageal reflux disease (GORD)
- Metabolic syndrome
- Urinary incontinence
- Obstructive sleep apnoea and breathing problems
- Chronic kidney disease
- Various types of cancer, including but not limited to: breast, colon, endometrial, oesophageal, kidney, ovarian and pancreatic cancer
- Knee osteoarthritis
- Gallstone disease
- Thrombosis
- Gout
- Heart attack or stroke
Why is BMI important to know?
BMI is a good way to check your risk of diseases related to body fat (adiposity). Generally, the higher your BMI, the greater the chance of developing other chronic obesity-related diseases.6-23 Click on the Your health risk item above to find out more.
Remember to ask your healthcare professional for more information about any of these diseases and how they relate to your BMI.
What are the limits of BMI?
BMI is a simple and objective measurement, but it can be misleading in certain cases and for some groups of people. Research has shown that BMI is less accurate in predicting the risk of disease in people who are older, athletes, those who are tall or short, and those with more muscular body types. For example, elite athletes or bodybuilders have more muscle and weigh more, which makes their BMI higher.24,25
BMI also doesn't take into account:16,24
- Hereditary risk factors associated with weight-related diseases, such as metabolic syndrome
- Environmental and lifestyle factors other than body weight that can contribute to your risk of developing chronic diseases
- How body fat is distributed in individuals
It's important to remember that living with overweight or obesity doesn't necessarily mean you're unhealthy, just as being at a ‘normal’ weight doesn't mean you're healthy. Your BMI doesn't define you, but knowing and understanding your BMI can be a powerful tool for taking charge of your own health.
Regardless of your BMI, healthcare professionals recommend having a healthy diet and lifestyle. Talk to a doctor about your weight and health and evaluate what actions may be needed.
What's behind weight gain?
Obesity isn't a matter of willpower. It's a complex condition influenced by genetics, hormones and other biological factors.
Tools to help you
Essential tools to monitor your health and have productive conversations with a doctor.
Take the first step and find the doctor for you
Talk to a doctor about treatment options that could help prevent the weight you lose from coming back.
References
- Rueda-Clausen CF, et al. Canadian Adult Obesity Clinical Practice Guidelines: Assessment of People Living with Obesity. Available at: obesitycanada.ca/guidelines/assessment. Accessed April 2025.
- Brown J, et al. Canadian Adult Obesity Clinical Practice Guidelines: Medical Nutrition Therapy in Obesity Management. Available from: obesitycanada.ca/guidelines/nutrition. Accessed April 2025.
- Chao A, et al. J Health Psychol 2015;20:721–9.
- Yumuk V, et al. Obes Facts 2015;8:402–24.
- Taheri S, et al. PLoS Med 2004;1:e62.
- Prospective Studies Collaboration. Lancet 2009;373(9669):1083–96.
- Guh DP, et al. BMC Public Health 2009;9:88.
- Klop B, et al. Nutrients 2013;5(4):1218–40.
- Adair T & Lopez AD. BMC Med 2020;18(1):199.
- Gelber RP, et al. Am J Hypertens 2007;20(4):370–7.
- Lee HJ, et al. PLoS One 2018;13(3):e0195210.
- Panidis D, et al. Fertil Steril 2008;89(4):899–906.
- Dong C, et al. Int J Obes Relat Metab Disord 2004;28(6):790–5.
- Loomis AK, et al. J Clin Endocrinol Metab 2016;101:945–52.
- Zafar S, et al. Saudi J Gastroenterol 2008;14:53–57.
- Han TS, et al. JRSM Cardiovasc Dis 2016;5:2048004016633371.
- Subak LL, et al. J Urol 2009;182(6 Suppl):S2–S7.
- Modena DAO, et al. Rev Assoc Med Bras (1992) 2017;63(10):862–8.
- Herrington WG, et al. PLoS One 2017;12:e0173515.
- Bhaskaran K, et al. Lancet 2014;384:755-65.
- Zheng H, et al. BMJ Open 2015;5:e007568.
- Su YP, et al. BMC Gastroenterol 2019;19:117.
- Bai L, et al. Arthritis Res Ther 2021;23:69.
- Heymsfield SB, et al. Obes Rev 2016;17:262–75.
- Romero-Corral A, et al. Int J Obes (Lond) 2008;32:959–66.
You might also like
AU23OB00080 - July 2025