How do I know if I am at a healthy weight?

This depends on your height and your overall health.

Doctors use a special measure called “body mass index,” or “BMI,” to help understand a person’s weight. Your weight and height are used to calculate your BMI (figure 1). Based on this number, you fall into 1 of the following categories:

• Underweight – BMI under 18.5
• Healthy weight – BMI between 18.5 and 24.9
• Overweight – BMI between 25 and 29.9
• Having obesity – BMI 30 or greater

Your doctor or nurse will often want to calculate your BMI at your medical appointments. But it’s important to remember that your weight and BMI are just 1 piece of your overall health. Someone with a lower BMI might not be healthy overall, and someone with a higher BMI can still be healthy.

How does my weight affect my health?

Having obesity increases the risks of many different health problems. It can also make it harder for you to move, breathe, and do other things that people who are at a healthy weight can do easily.

People with obesity are more likely to get diabetes, heart disease, cancer, and lots of other health problems. People with obesity also live less time than people of normal weight. That’s why it’s important to try to keep your weight in a healthy range.

What should I do if I want to lose weight?

If you would like to lose weight, you can start by talking to your doctor or nurse. They can help you make a plan to lose weight in a healthy way. It can also help to work with a dietitian (food expert).

In general, to lose weight, you have to eat fewer calories and move your body more.

Studies have compared different diets such as the Atkins diet, the Zone diet, and the Weight Watchers diet. No specific diet is better than any other. Any diet that reduces the number of calories you eat can help you lose weight, as long as you stick with it. You should try to find an eating pattern that works for you. A dietitian can help you make healthy changes to your diet while making sure that you get the nutrients your body needs.

Physical activity works the same way. You can walk, dance, garden, or even just move your arms while sitting. Even gentle forms of exercise are good for your health. For weight loss, the important thing is to increase the number of calories you burn by moving more. And you have to keep doing the extra activity.

If you go on a diet for a short time, or increase your activity for a while, you might lose weight. But you will regain the weight if you go back to your old habits. Weight loss is about changing your habits for the long term.

The best way to start is to make small changes and stick with them. Then, little by little, you can add new changes that you also stick with.

Are there medical treatments that can help me lose weight?

There are medicines and surgery to help with weight loss. But these treatments are only for people who have not been able to lose weight through diet and exercise.

Weight loss treatments do not take the place of diet and exercise. People who have those treatments must also change how they eat and how active they are.

How do weight loss medicines work?Weight loss medicines work by reducing your appetite or by changing the way you digest food. They are appropriate only for people who:

• Have a BMI of 30 or greater, or
• Have a BMI between 27 and 29.9 and also have weight-related medical problems, such as diabetes, heart disease, or high blood pressure

Can I try herbal or non-prescription medicines to lose weight?

Many herbal weight loss medicines are unsafe or do not work. Check with your doctor or pharmacist before you take any herbal weight loss medicines. There is also an over-the-counter (non-prescription) version of a prescription medicine called orlistat (brand name: Alli). It is probably safe to try, but it can cause unwanted side effects, such as cramps, burping, and gas.

Some weight loss medicines are sold over the internet. However, they can contain harmful ingredients and be unsafe.

How does weight loss surgery work?

Surgical procedures for weight loss work by making your stomach smaller. Some types of surgery also change the path that food takes through your digestive system. With these types, your body absorbs fewer calories and nutrients from food.

Weight loss surgery is appropriate only for people who:

• Have a BMI greater than 40
• Have a BMI of 35 to 39.9 and also have medical problems, such as diabetes, heart disease, or high blood pressure
• Have a BMI of 30 or greater and have diabetes that cannot be controlled in other ways

How do I decide if weight loss treatment is right for me?

If your doctor suggests weight loss treatment, ask these questions:

• About how much weight can I expect to lose, and how long will that take? – This depends on the treatment. There are several different types of surgeries to help with weight loss. The amount of weight loss and how long it takes to lose weight is different for each one.
• What are the risks of treatment for someone like me? – All weight loss medicines can have side effects. All weight loss surgeries can lead to infection, bleeding, the need for other operations, and even death. To reduce the risk of these problems with surgery, make sure that your surgeon is very experienced and that you are treated at a certified “Center of Excellence.”
• What changes will I need to make to my diet and lifestyle? – Weight loss treatments are not “shortcuts” that you can take to avoid making lifestyle changes. People must also change how they eat and how active they are. No single weight loss treatment works on its own. Sometimes, people can get surgery only after they lose some weight on their own through diet and exercise first. Working with a dietitian can help.
• Will I be able to process food normally? – Some types of weight loss surgeries leave people unable to get all of the nutrients that they need from food. People who have this problem must take vitamin and mineral supplements for the rest of their lives.