Top of the page
Obesity means having an unhealthy amount of body fat. This puts your health in danger. It can lead to other health problems, such as type 2 diabetes and high blood pressure.
Obesity is complex. You gain weight when you take in more calories than you burn off. But other things can affect your weight. These things may include your genetic makeup, what and how you eat, how active you are, what health problems you may have, and what medicines you may take.
To know if your weight is in the obesity range, your doctor looks at your body mass index (BMI) and waist size.
BMI is a number that is calculated from your weight and your height. To figure out your BMI for yourself, you can use an online tool, such as https://www.diabetes.ca/managing-my-diabetes/tools---resources/body-mass-index-(bmi)-calculator on the Diabetes Canada website.
If your BMI is 30.0 or higher, it falls within the obesity range. Keep in mind that BMI and waist size are only guides. They are not tools to determine your ideal body weight.
The best way to lose weight is to eat less and move more. Little steps mean a lot. Losing just 10% of your body weight can make a difference in your health.
Some people take medicines or have surgery to help them lose weight. Your doctor may also suggest counselling. If you use food to cope with depression, loneliness, anxiety, or boredom, you can learn new skills to deal with those feelings.
You'll have the most success if you make a long-term plan with your doctor. Your first goal will likely be to improve your health, not to reach an ideal weight.
If you have a BMI in a certain range and have not been able to lose weight with diet and exercise, medicine or surgery may be an option for you.
If you have a BMI of at least 30.0 (or a BMI of at least 27.0 and another health problem related to your weight), ask your doctor about weight-loss medicines. They work by making you feel less hungry, making you feel full more quickly, or changing how you digest fat. Medicines are used along with diet changes and more physical activity to help you make lasting changes.
If you have a BMI of 40.0 or more (or a BMI of 35.0 or more and another health problem related to your weight), your doctor may talk with you about surgery. Weight-loss surgery has risks, and you will need to work with your doctor to compare the risk of having obesity with the risks of surgery.
With any option you choose, you will still need to eat a healthy diet and get regular exercise.
Health Tools help you make wise health decisions or take action to improve your health.
Obesity is complex. You gain weight when you take in more calories than you burn off. But other things can affect your weight. These things include:
If one of your parents is obese, you're more likely to be overweight too. But other things can also put you at risk.
Obesity can raise your risk for certain health problems. These may include type 2 diabetes, high blood pressure, coronary artery disease (CAD), and stroke. If you have healthier habits or lose weight, you can lower your risk for these conditions.
Doctors use a tool called BMI (body mass index) to see if your weight could be unhealthy. If your BMI is 30 or higher, your weight may be putting your health in danger. If you are Asian, your health may be at risk at 27.5 or higher.footnote 1
Other tests include measuring your waist and percentage of body fat. Your doctor may also want to know your basal metabolic rate (BMR) to find out how many calories you need each day.
If you are concerned that your child is—or could become—overweight, talk with your doctor. Doctors use growth charts or the body mass index (BMI) to check a child's weight. Your doctor also may ask about your child's diet and family medical history. Your child also may have a physical exam and some tests.
You might want to try weight-loss medicines or have weight-loss surgery if:
Most people have more success when they make small changes, one step at a time. For example, you might eat an extra piece of fruit or add more vegetables to your meals.
One of the best ways to increase your activity is by walking.
Medicine may help you lose a small amount of weight. But without permanent changes in eating and exercise habits, most people gain weight again after they stop taking the medicine.
After surgery, you will need to make big, lifelong changes in how you eat, including smaller portions and different foods.
If you're thinking about losing weight, it can be hard to know where to start. Your doctor can help you set up a weight loss plan that best meets your needs. You may want to take a class on nutrition or exercise, or you could join a weight loss support group. If you have questions about how to make changes to your eating or exercise habits, ask your doctor about seeing a registered dietitian or an exercise specialist.
It can be a big challenge to lose weight. But you don't have to make huge changes at once. Make small changes, and stick with them. When those changes become habit, add a few more changes.
If you don't think you're ready to make changes right now, try to pick a date in the future. Make an appointment to see your doctor to discuss whether the time is right for you to start a plan.
You might have heard that a certain diet plan helped another person lose weight. But that doesn't mean that it will work for you.
It's very hard to stay on a diet that includes lots of big changes in your eating habits. If you want to get to a healthy weight and stay there, making healthy lifestyle changes will often work better than dieting. These steps can help.
Work with your doctor to create a plan that's right for you.
He or she can show you how to make healthy changes in your eating habits.
Part of reaching a healthy weight is being physically active.
Having a lot of stress in your life can make it hard to focus on making healthy changes to your daily habits.
You are likely to do better at losing weight if you keep track of what you eat and what you do.
Be ready. Choose to start during a time when there are few events like holidays, social events, and high-stress periods. These events might trigger slip-ups.
Decide on your first few steps. Most people have more success when they make small changes, one step at a time. For example, you might switch a daily candy bar to a piece of fruit, walk 10 minutes more, or add more vegetables to a meal.
Line up your support people. Make sure you're not going to be alone as you make this change. Connect with people who understand how important it is to you. Ask family members and friends for help in keeping with your plan. And think about who could make it harder for you, and how to handle them.
Try tracking. People who keep track of what they eat, feel, and do are better at losing weight. Try writing down things like:
Look and plan. As you track, look for patterns that you may want to change. Take note of:
When you stray from your plan, don't get upset. Figure out what made you slip up and how you can fix it.
If you decide to join a weight-loss program, ask some questions: Does the program provide counselling? Is the staff qualified? What can you eat? What percentage of people get to the maintenance phase of the program? What are the risks? What is the total cost?
Doctors prescribe weight loss medicines for people who are obese or overweight and have other health problems, such as high blood pressure or diabetes. These medicines may help some people who haven't been able to lose weight with diet and exercise.
Here are some examples of weight-loss medicines. For each item in the list, the generic name is first, followed by any brand names.
Depending on the medicine they take, some people are able to lose from 2 to 11 kilograms (4 to 24 pounds). Weight-loss medicines are used along with healthy eating and being more active. Without those lifestyle changes, you will gain the weight back if you stop taking the medicine.
Over-the-counter weight-loss products include appetite suppressants and water-loss pills. Many of these have never been proved effective. And those that are effective often come with warnings.
Bariatric surgery is surgery to help you lose weight. This type of surgery is only used for people who are very overweight and have not been able to lose weight with diet and exercise.
This surgery makes the stomach smaller. Some types of surgery also change the connection between your stomach and intestines.
Having weight-loss surgery is a big step. After surgery, you'll need to make new, lifelong changes in how you eat and drink.
This type of surgery may be considered if your body mass index (BMI) is at least 40, or if it's at least 35 and you have other weight-related health problems. If your BMI is 35 or higher, surgery may be done if you have tried for at least 6 months to lose weight.
For more information about what is available in Alberta visit Bariatric Surgery in Alberta.
CitationsPurnell JQ (2011). Obesity. In EG Nabel, ed., ACP Medicine, section 6, chap. 12. Hamilton, ON: BC Decker.
Adaptation Date: 2/8/2023
Adapted By: Alberta Health Services
Adaptation Reviewed By: Alberta Health Services
To learn more about Healthwise, visit Healthwise.org.
© 1995-2023 Healthwise, Incorporated. All rights reserved. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.