Learn About Weight and Obesity
In today's society, with so much media attention focused on body image, it's hard to grasp the concept of a healthy weight.
Having a large percentage of body fat, regardless of how much you weigh, is unhealthy. You could be of normal weight or underweight and still have an unhealthy amount of body fat. Being overweight means you have a heavy weight, but not necessarily too much body fat. For example, people who are muscular weigh more than those who are not; their extra weight comes from muscle, not body fat.
Finding 1: Obesity can raise some cancer risks.
Researchers with the National Cancer Institute have determined that certain cancers of the breast (occurring after menopause), colon and rectum, kidney, esophagus, pancreas, thyroid, gall bladder, the lining of the uterus (endometrium) and possibly other cancer types are associated with obesity and physical inactivity.
Finding 2: Obesity is tied to heart attacks in younger adults.
Obesity has been linked to a rise in fatal heart attacks in young people. In people ages 15 to 34, the CDC says, the death rate from heart attacks rose 32 percent among women and 10 percent among men during the 1990s.
Finding 3: Obesity can ruin your day.
For those who are obese, daily life itself is harder, studies show. Simple tasks such as carrying groceries, walking up stairs, kneeling and stooping are more difficult for the obese. Sleep apnea, which is more prevalent among obese people, is often a cause of lethargy during the day.
According to the CDC, obese people are also more likely to have chronic diseases such as coronary artery disease, type 2 diabetes and hypertension. Stroke, dyslipidemia (high levels of cholesterol or triglycerides) and osteoarthritis are also more common among obese people.
Finding 4: Obesity speeds up girls' puberty.
A study published in the journal Pediatrics found that girls who weigh too much tend to develop breasts and pubic hair at age 8 or 9, earlier than their peers. Early puberty may put girls at risk for behavioral and emotional problems.
Finding 5: Obesity is a cause of diabetes in kids.
Doctors believe increases in childhood obesity help explain the sharp increase in type 2 diabetes among kids. In type 2 diabetes, the body is unable to make enough insulin or use insulin effectively. Experts believe that in the next 10 years more children will have type 2 diabetes than type 1 diabetes. In the past, almost all children with diabetes suffered from type 1 diabetes.
The American Academy of Pediatrics says most children with type 2 diabetes are obese. The disease usually turns up in middle to late puberty. Children who get little exercise, eat too much and have a family history of diabetes are at highest risk.
Finding 6: Obesity in middle age increases risk for dementia.
Although studies have linked obesity and diabetes to an increased risk for dementia and diseases such as Alzheimer’s, the National Institutes of Health says researchers still aren’t sure whether these conditions actually cause them.
Overweight or obese?
The first step toward tackling weight is to know what you are dealing with.
According to National Heart, Lung and Blood Institute (NHLBI) guidelines, an assessment of whether you are overweight involves using three key measures:
- Body mass index (BMI)
- Waist circumference
- Risk factors for diseases and conditions associated with obesity, which include high blood pressure, high level of LDL ("bad") cholesterol, high triglycerides, high blood sugar and smoking
Body mass index
The first measurement to find out whether you are overweight or obese involves determining your body mass index, or BMI. To calculate your BMI, multiply your weight in pounds by 703, then divide by your height in inches. Then divide by your height in inches again.
BMI = [Weight in pounds / (Height in inches) X (Height in inches)] X 703
For example, if you weigh 162 pounds and are 69 inches tall, your BMI is 23.9, or (162 x 703) ÷ (69 x 69) and is normal.
- A BMI of 18.4 or below: Underweight
- A BMI of 18.5 to 24.9: Normal
- A BMI of 25 to 29.9: Overweight
- A BMI of 30 or greater: Obese
For people who are considered obese or those who are overweight and have two or more risk factors, the NHLBI guidelines recommend losing weight.
Although BMI is a reliable indicator of total body fat, it does have some limits. It may overestimate body fat in athletes and others with a muscular build. It may underestimate body fat in older adults and in others who have lost muscle mass.
Abdominal fat/waist circumference
Another way to determine whether you are obese or overweight is to measure your abdominal fat, which can predict the risk for diseases associated with obesity. Determine your waist circumference by placing a measuring tape snugly around your waist. Your waist circumference is a good indicator of your abdominal fat. Your risk for obesity-related diseases increases with a waist measurement of more than 40 inches in men and more than 35 inches in women.
You should use your abdominal fat measurement along with your BMI to assess your risk. People who are overweight (BMI of 25 to 29.9) but don't have a large waist measurement and have fewer than two risk factors may need only to prevent additional weight gain rather than to lose weight.
If you are overweight and have other risk factors for obesity-related diseases, you should lose weight. If you are obese, you should lose weight even if you have no other risk factors.