What is obesity? If you’re obese, it means you weigh much more than is healthy for you. It happens because you eat more calories than your body uses. The extra calories are stored as fat.
Being obese is more than being just a few pounds overweight. Obesity can cause health problems such as diabetes, high blood pressure, arthritis and heart disease.
Losing weight isn’t easy. You’ll need to change the way you eat and the amount of exercise you get. But if you make these changes, you’ll be healthier.
Key points about obesity
- Obesity is a serious medical condition.
- Losing even a small amount of weight can lower the risk to your health.
- Cutting down on calories, getting more exercise, and learning good eating habits can help you lose weight.
- Medical treatments might also help.
- You’re more likely to lose weight if you get help from a health professional.
- If you’re very obese, surgery can help you lose a lot of weight. But there are risks with surgery, so doctors usually recommend it only if your weight is a danger to your health.
What’s a healthy weight?
When doctors talk about a “healthy” or “ideal” weight, they mean a weight that lowers your risk of getting serious health problems, such as heart disease or high blood pressure. It’s not based on how thin you would like to look.
Most doctors use the body mass index (BMI for short) to figure out whether you’re at a healthy weight. Your BMI is a single number that’s worked out from your height and weight. You can work out your own BMI.
This table shows what the different BMI scores mean.
| BMI | Weight Status |
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Normal |
| 25.0 – 29.9 | Overweight |
| 30.0 – 39.9 | Obese |
| 40.0 and more | Extreme Obesity |
You might have read that there are problems with using someone’s BMI to find out if they’re overweight. For example, an athlete who’s very muscular might have a BMI that suggests they’re overweight, even though they’re healthy. That’s because muscle is heavier than fat. However, for most people, working out their BMI is a quick and simple way of finding whether their weight is healthy.
How your body uses food
Food gives you energy. The amount of energy in food is measured in calories (short for kilocalories, or kcal).
Your body needs energy all the time, especially for moving and keeping warm. Different people need different amounts of energy. The amount of energy you need depends on your metabolic rate. And the more active you are, the more energy you use.
Your brain helps you stay a healthy weight. It helps to balance how much you eat with how much energy you burn. Your brain sends out “hungry” or “full” signals that make you want to eat or stop eating.
What happens in obesity?
About obesity
Being obese is not the same as being a few pounds overweight. Doctors say someone is obese if their BMI is 30 or higher (see the table above). For most people, having a BMI greater than 30 means they’re at least 30 pounds overweight.
If you’re obese, it means you’re eating more calories than your body is using up as energy. Your body stores the extra calories as fat.
Doctors aren’t sure why some people eat more food than they need. There are probably lots of reasons.
One theory is that early humans probably had to go for long periods without food, so our bodies needed to be able to store fat easily in order to survive. But nowadays we can get food easily. Some scientists think that our bodies haven’t had enough time to evolve and adapt to a plentiful supply of food. So, our bodies still work as if we might have to face a famine.
And for some people who are obese, their “full” and “hungry” signals may not work properly.
For some people, this happens because of a medical condition, or because of side effects of medications. Medical conditions that can cause obesity include having an underactive thyroid. Medicines that can make you put on weight include some antidepressants and corticosteroids.
(information from – http://www.consumerreports.org/health/conditions-and-treatments/obesity/what-is-it.htm)
