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What is obesity?
Obesity is having an excess amount of body fat for your height. It raises your risk for serious health problems. These include type 2 diabetes and high blood pressure.
How do you know if your weight is in the obesity range?
To know if your weight is in the obesity range, your doctor looks at your body mass index (BMI). BMI is a number that is calculated from your weight and your height. If your BMI is 30.0 or higher, it falls within the obesity range. Talk with your doctor about what a healthy weight is for you.
To figure out your BMI for yourself, you can use an online tool, such as www.nhlbi.nih.gov/health/educational/lose_wt/BMI/bmicalc.htm on the National Institutes of Health website.
How is obesity treated?
Losing even 5% of your body weight can improve your health.footnote 1 Some people can lose weight by eating less and moving more. Some people take medicines or have surgery to help them lose weight.
You're more likely to have success if you make a plan with your doctor. Your doctor can help you set goals that matter to you and focus on ways to improve your health.
Your doctor may also suggest counseling or other types of support. If you use food to cope with depression or boredom, counseling can help you learn new skills to manage your feelings.
Can you take medicines or have surgery to lose weight?
Weight-loss medicine or surgery may be helpful for people who have a BMI in a certain range or who have not been able to lose weight with diet and exercise.
- Weight-loss medicine may be an option if you have obesity or if you are overweight and have a health problem related to your weight. These medicines work by making you feel less hungry, making you feel full more quickly, or changing how you digest fat.
- Weight-loss (bariatic) surgery may be an option if you have obesity and have not been able to lose a meaningful amount of weight and keep it off. It may also be offered if you have obesity and have weight-related health problems that have not improved with other options. Weight-loss surgery makes the stomach area smaller so it fills up with less food. This surgery is safe and effective for many people.
Your doctor can help you understand your options so you can decide what's right for you. With any treatment you choose, healthy eating and regular exercise can help you make lasting changes. Your doctor may also suggest counseling or other types of support to learn new ways to manage your feelings.
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What causes it?
Obesity is complex. There is no single known cause. But many things increase the risk of obesity, including your genes, what and how you eat, your activity level, and the rate at which your body burns calories (basal metabolic rate). The medicines you take and health conditions you have can also affect your weight.
What Increases Your Risk
Many things can make obesity more likely. These include:
- Your genes.
Your genes have a major effect on your weight. For example, if one of your parents has obesity, you're more likely to be overweight too. Your genes also affect:
- How quickly your body uses energy (calories) when you're at rest (your basal metabolic rate).
- Some people are born with a higher metabolic rate than others. They naturally burn more calories than other people.
- A very low-calorie diet will lower your metabolic rate. A lower metabolic rate makes it easier to gain weight, because you don't burn calories as fast.
- Your body signals, such as your appetite, food cravings, and when you feel hungry or full.
- Your fat distribution. You can't change where your body stores fat. Some people store fat in the belly (abdomen). Others store more fat in the hips and thighs.
- How quickly your body uses energy (calories) when you're at rest (your basal metabolic rate).
- What and how you eat.
Many things influence eating behavior, including your genes, emotions, and habits and having limited access to healthy food.
- How active you are.
A lack of physical activity is a factor in weight gain. Being active helps prevent weight gain and can help you maintain weight loss. It's also good for your heart. And regular physical activity can raise your metabolic rate, so you burn more calories, even when you're resting.
- Certain medicines or health problems.
Some conditions and medicines may also cause weight gain. Examples include having Cushing's syndrome or hypothyroidism and taking certain antidepressants or corticosteroids.
- Normal aging.
People tend to gain weight through their adult years until about age 65. Gaining even a few pounds a year can lead to obesity over time.
- Unhealthy sleep habits.
Obesity may be related to sleep patterns such as not getting enough sleep, having a late bedtime, and working night shifts.
Obesity can raise your risk for certain health problems. These include type 2 diabetes, high blood pressure, coronary artery disease (CAD), and stroke. You can lower your risk for these conditions by making some changes to form healthier habits or lose weight.
Exams and Tests
Doctors use a tool called BMI (body mass index) to assess weight. For most people, BMI reflects the amount of body fat they have and their health risks related to it. If your BMI is 25 or higher, your weight may be raising your risk for health problems. But there's more to your health than a single number. Talk with your doctor about what a healthy weight is for you.
Your doctor may also:
If you are concerned about your child's weight
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.
Losing even 5% of your body weight can improve your health.footnote 1 Some people can lose weight by making lifestyle changes, including eating less and moving more. Some people take medicines or have surgery to help them lose weight.
You may be more likely to have success if you make a plan with your doctor. Your doctor can help you set goals that matter to you and focus on ways to improve your health.
Your doctor may also suggest counseling or other types of support. If you use food to cope with depression, loneliness, anxiety, or boredom, counseling can help you learn new skills to manage your feelings.
A good strategy is to make small changes focused on improving your health. For example:.
- Make healthy changes in your eating habits. For example, you might add more vegetables to your meals.
- Be more active. For many people, walking is a good way to get more active. But any physical activity can benefit your health. So try to find ways to be active that you enjoy.
Weight-loss medicines make you feel less hungry, make you feel full more quickly, or change how you digest fat. Weight-loss surgery makes the stomach area smaller so it fills up with less food. It is safe and effective for many people.
These treatments may be an option if:
- You have not been able to lose weight with healthy eating and more activity.
- You have a health problem related to obesity, such as heart disease or diabetes.
- You keep gaining weight.
- You have lost weight but regained it.
Your doctor can help you understand your options so you can decide what's right for you. With any treatment you choose, making long-term changes in eating habits and activity will help you reach your goals and maintain a weight that's healthy for you.
Weight-Loss Strategies and Programs
It can be a challenge to lose weight. But your doctor can help you make a weight-loss plan that meets your needs.
You don't have to make a lot of big changes at once. A better idea might be to focus on small changes and stick with them. When those changes become habit, you can add a few more changes.
Some people find it helpful to take an exercise or nutrition class. If you have questions, ask your doctor about seeing a registered dietitian or an exercise specialist. You might also think about joining a weight-loss support group.
If you're not ready to make changes right now, try to pick a date in the future. Then make an appointment with your doctor to talk about when and how you'll get started with a plan.
Making a weight-loss plan
If you want to get to a weight that's healthy for you, making healthy lifestyle changes will probably work better than dieting. In the long run, diets don't work for most people. Try these steps.
- Make a plan for change.
Your doctor can help you create a plan that's right for you. This includes setting a weight loss goal. For most people, a goal of losing 5% to 10% of their weight is a good place to start. Your plan will also include small changes you can make in your nutrition, eating habits, and physical activity.
- Try to be more active.
Make physical activity a part of your daily life. Start slowly if you haven't been active.
- Try tracking your food and activity.
Keeping track of what you eat, your activity, and your weight can help you succeed with your plan. There are free apps that make tracking easy.
- See a dietitian.
A dietitian can show you how to make long-term healthy changes in your eating habits.
- Try to manage stress.
Having a lot of stress in your life can make it hard to focus on making healthy changes to your daily habits.
How can you stay on your plan for change?
Be ready. Plan to start during a time when you don't have too many events like holidays, social events, and high-stress periods. It may be harder to stay with your plan during these times.
Decide on your first few steps. A good strategy is to make small changes focused on improving your health. For example, you might have a piece of fruit instead of a less healthy snack, plan a 10-minute daily walk, or add more vegetables to a meal.
Find your support people. Connect with people who understand how important these changes are to you. Ask caring family members or friends to help you stay with your plan. If there are people who might make it harder to stick to your plan, think about how you can handle that.
Try tracking. Keeping track of your food, activity, and weight can help you succeed with your plan. There are lots of free apps that make tracking easy. Or you can simply write down things like:
- What and how much you ate and how many calories it had.
- Details about where you ate, who was with you, and how you felt before and after eating.
- What you did to be active and how long you were active.
Learn from tracking. Tracking can help you see your progress, remind you of your successes, and avoid setbacks. As you track, look for eating patterns that you may want to change and note your successes. Notice things like:
- When you eat and whether you skip meals.
- How often you eat out.
- How many fruits and vegetables you eat.
- When you eat beyond feeling full.
- When and why you eat for reasons other than being hungry.
These patterns can help you find ways to make small changes to achieve your weight goals.
If you stray from your plan, don't be hard on yourself. Think about what happened and ways to avoid doing the same thing in the future.
If you're thinking of joining a weight-loss program, learn as much as you can about it first. What kind of changes in eating and exercising does it involve? Does it provide counseling? What does it cost? It's a good idea to talk to your doctor about the program before you start.
Tips for Getting to a Healthy Weight
- Try to choose healthy foods. You might be more successful if you work on changing one eating habit at a time. All foods, if eaten in moderation, can be part of healthy eating. Try to:
- Eat a variety of foods from each food group. Include grains, vegetables, fruits, dairy, and protein foods.
- Limit foods high in fat, sugar, and calories.
- Eat slowly. And don't do anything else, such as watch TV, while you are eating.
- Pay attention to portion sizes. It may help to put your food on a smaller plate.
- Plan your meals ahead of time when you can. You'll be less likely to grab something that's not as healthy.
- Focus on making healthy choices instead of dieting.
- Get active. Regular activity can help you feel better, have more energy, and burn more calories. If you haven't been active, start slowly. A good goal to work toward is 30 minutes of moderate activity on most days of the week. If you can do that, then gradually increase your activity. Try for 60 minutes a day, at least 5 days a week.footnote 1 There are a lot of ways to fit activity into your life. For example:
- Walk or bike to the store. Or walk with a friend, or walk the dog.
- Do yard work or try gardening.
- Use the stairs instead of the elevator, at least for a few floors.
- Try an online workout video that fits your pace.
- If you have limited mobility, try some seated exercises, such as lifting light weights or doing leg raises.
- Change your thinking. Your thoughts have a lot to do with how you feel and what you do. When you're trying to reach a healthy weight, changing how you think about certain things may help. Here are some ideas:
- Try not to compare yourself to others. Healthy bodies come in all shapes and sizes.
- Pay attention to how hungry or full you feel. When you eat, be aware of why you're eating and how much you're eating.
- Ask your doctor about other health professionals who can help you. For example:
- A dietitian can help you make healthy changes in your diet.
- An exercise specialist can help you develop a safe and effective exercise program.
- A counselor or psychiatrist can help you cope with issues such as depression, anxiety, or family problems that can make it hard to focus on reaching a weight that's healthy for you.
- Get support from caring friends or family members, your doctor, or a support group.
- Fitness: Getting and Staying Active
- Fitness: Using a Pedometer, Step Counter, or Wearable Device
- Healthy Eating
- Healthy Eating: Starting a Plan for Change
- Physical Activity and Weight Loss
- Quick Tips: Cutting Calories
- Tips for Maintaining Weight Loss
- Weight Loss by Limiting Calories
- Weight Management
Weight-loss medicines may be an option for people who have obesity or who are overweight and have weight-related 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 medicines used for weight loss. Many are approved by the U.S. Food and Drug Administration (FDA) to treat obesity or overweight. Other medicines that may have the same ingredients are also used to help with weight loss.
- Semaglutide (Wegovy, Ozempic). It may help you eat less. It's given as a shot or pill.
- Liraglutide (Saxenda). This medicine may help you eat less. It's given as a shot once a day.
- Tirzepatide (Zepbound). This medicine may help you eat less. You take this medicine as a shot once a week.
- Phentermine/topiramate (Qsymia). This medicine combines the drugs phentermine and topiramate. Taking it once a day can help you eat less.
- Bupropion/naltrexone (Contrave). This medicine may reduce your appetite. It may help you avoid overeating.
- Orlistat (Xenical). Orlistat prevents some of the fat calories you eat from being absorbed in your intestines. It's also available without a prescription under the brand name Alli. Alli is half as strong as Xenical.
How well medicines work
Many people can lose 5% to 16% or more of their body weight, depending on which medicine they take.footnote 2 Weight-loss medicines are used long-term with healthy eating and being more active. Learning new ways to manage challenges and setbacks can also help people reach and maintain a weight that's healthy for them.
Over-the-counter weight-loss products
Orlistat (Alli) is the only weight-loss product approved by the U.S. Food and Drug Administration that's available without a prescription. Other over-the-counter (OTC) products that claim to help with weight loss haven't been proven to be safe or effective and may be harmful. Talk to your doctor before using any OTC weight-loss product.
What is weight-loss (bariatric) surgery?
Bariatric surgery is surgery to help people lose weight and improve health problems related to weight. It may also be called metabolic surgery. This type of surgery is used for people who have obesity. Weight-loss surgery may be an option for people who have not been able to lose weight or improve weight-related health problems with diet, exercise, and medicines.
There are different types of bariatric surgery. They make the stomach smaller. Some types of surgery also change the connection between your stomach and intestines.
After surgery, you'll need to make new, lifelong changes in how you eat and drink. You'll have the support of your health care team to make these changes. These changes will help you reach your goals and stay at a weight that is healthy for you.
This type of surgery may be an option if you have obesity or health problems related to your weight. You and your doctor may consider surgery if you have not been able to lose weight or improve health problems with healthy eating, exercise, or weight-loss medicines.
- Tondt J, et al. (2023). Obesity Algorithm eBook, presented by the Obesity Medicine Association. https://obesitymedicine.org/obesity-algorithm. Accessed October 30, 2023.
- Drugs and devices for weight management. (2022). Medical Letter on Drugs and Therapeutics, 64(1651): 81–88a. Accessed July 12, 2023.
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Current as of: May 13, 2023
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