Something about obesity

     Obesity involves having an abnormally high proportion of body fat. Doctors define obesity as having a body mass index (BMI) of 30 or higher and overweight as having a BMI of 25 or higher.

     Weight is largely determined by how you balance your intake of calories from food with the energy you use in everyday activities. If you consume more calories than you use, you gain weight. Your body stores calories that you don't need for energy as fat.

     Fat is important for storing energy and insulating your body, among other functions. The human body can handle carrying some extra fat, but beyond a certain point, body fat can begin to interfere with your health.

     Eating too many calories and not getting enough physical activity are the main causes of obesity, especially in combination. But many factors can contribute to obesity.

Factors that increase your risk of being obese include:

• Diet. Regular consumption of high-calorie foods, such as fast foods, contributes to weight gain. High-fat foods are dense in calories. Loading up on soft drinks, candy and desserts also promotes weight gain. Foods and beverages like these are high in sugar and calories.
• Inactivity. Sedentary people are more likely to gain weight because they don't burn calories through physical activities.
• Psychological factors. Some people overeat to cope with problems or deal with emotions, such as stress or boredom.
• Genetics. If one or both of your parents are obese, your chances of being overweight are greater. Your genes may affect the amount of body fat you store and where that fat is distributed. But, your genetic makeup doesn't guarantee that you'll be obese.
• Age. As you get older, you tend to be less active. In addition, the amount of muscle in your body tends to decrease with age. This lower muscle mass leads to a decrease in metabolism. These changes also reduce calorie needs. If you don't decrease your caloric intake as you age, you'll likely gain weight.
• Cigarette smoking. Smokers tend to gain weight after quitting. This weight gain may be partially due to nicotine's ability to raise the rate at which your body burns calories (metabolic rate). When smokers stop, they burn fewer calories. Smoking also affects taste; quitting smoking makes food taste and smell better. Former smokers often gain weight because they eat more after they quit. However, cigarette smoking is still considered a greater threat to your health than is extra weight.
• Pregnancy. During pregnancy a woman's weight necessarily increases. Some women find this weight difficult to lose after the baby is born. This weight gain may contribute to the development of obesity in women.
• Medications. Corticosteroids and tricyclic antidepressants, in particular, can lead to weight gain. So can some high blood pressure and antipsychotic medications.
• Medical problems. Uncommonly, obesity can be traced to a medical cause, such as low thyroid function, excess production of hormones by the adrenal glands (Cushing's syndrome) or other hormonal imbalances, such as polycystic ovary syndrome. A low metabolic rate is rarely a cause of obesity. A medical problem, such as arthritis, can also lead to decreased activity, which can result in weight gain.
• Alcohol. Drinking alcohol adds calories to your diet — just one regular beer is about 150 calories. If you don't cut back somewhere else, adding just one beer daily could cause a weight gain of more than one pound a month. Additionally, excessive drinking can stimulate your appetite and make you less likely to control portion sizes.

When to seek medical advice:

How do you know whether you need to lose weight for medical reasons? These evaluations can help provide the answer:

• Body mass index (BMI). The BMI is a formula that uses weight and height to estimate body fat and health risks. If your BMI is between 19 and 24, you're considered in a healthy weight range for your height. If your BMI is between 25 and 29, you're considered overweight. And, if the figure is 30 or greater, you're considered obese and should talk to your doctor about losing weight for your health.
• Waist circumference. If you carry most of your fat around your waist or upper body, you may be referred to as apple shaped. If you carry most of your fat around your hips and thighs or lower body, you may be referred to as pear shaped. Generally, when it comes to your health, it's better to have the shape of a pear than the shape of an apple. If you have an apple shape — a potbelly or spare tire — you carry more fat in and around your abdominal organs. Abdominal fat increases your risk of many of the serious conditions associated with obesity. Women's waist measurements should be less than 35 inches. Men's should be less than 40 inches. If you have a large waist circumference, talk to your doctor about weight loss.

Talking to the doctor openly and honestly about your weight is one of the best things you can do for your health. The more your weight increases, the more medical problems you may face.

Also, talk to the doctor if you have weight-related medical conditions, such as high blood pressure, high blood cholesterol, diabetes and arthritis. These health conditions may improve if you're able to lose weight