Health care providers use body mass index (BMI), an approximate measure of body fat based on a person's height and weight, to determine whether a person's weight falls within a healthy range. Another simple measurement is waist circumference. There are also several methods of estimating the percentage of your weight that is fat, including skin-fold measurement, bioelectric impedance, and underwater weighing.
What's your BMI?Look at Table 1 to determine your BMI. Studies show that the BMI range associated with the lowest rate of illness and death is approximately 19–25 in men and 18–25 in women, so people with BMIs in this healthiest range are considered to be of normal weight. Higher BMIs are associated with progressively higher rates of illness and death. People with BMIs of 25–30 are considered overweight, and those with BMIs of 30 or higher are considered to have obesity. Obesity has been further subdivided into mild (BMI of 30–35), moderate (35–40), and severe (BMI of 40 and above). Severe obesity is roughly equivalent to being 80 pounds overweight if you are a woman or 100 pounds if you are a man.
If your BMI is lower than 18, you are considered underweight. Underweight people also have higher death rates than people of normal weight do, but many people in this category are underweight because they already have a severe illness, such as cancer, chronic infections, or anorexia.
What's your body shape?Your body shape depends largely on where you tend to carry your weight, usually centered on either your waist or your hips and thighs. If you carry fat mainly around the middle of your body (known as "apple-shaped"), you're more likely to develop diabetes and related health problems than if you tend to be heavier around your hips and thighs ("pear-shaped"). To measure your waist circumference, place a cloth tape measure around your bare abdomen just above your hipbones. Make sure the tape is snug and parallel to the floor. A waist circumference of more than 35 inches for women and more than 40 inches for men indicates a higher than normal risk.
What's your body fat percentage?You can estimate your body fat percentage by several different methods, but be aware that these tools aren't always accurate and doctors don't consider them useful to guide treatment. In general, these methods tend to be less accurate in people with obesity than in people who are slightly overweight or at a normal weight. But some athletes and people who are trying to tone their bodies while losing weight may find it motivates them to keep tabs on their body fat percentage. Healthy adult men have body fat percentages between 10% and 25%, whereas the range for women is between 18% and 32%. Higher percentages are considered abnormal and consistent with obesity. In children, body fat percentages above 25% in boys and 30% in girls are associated with being overweight.
Skin-fold thickness. A technician or health professional uses calipers, a measuring instrument, to gauge the thickness of a fold of skin on the body at several different sites, such as the upper arms, waist, and thighs. The measurements are entered into a formula to produce an estimate of body fat percentage. This method gives a reasonable estimate, but results often vary when different people take the measurements, making this test not very reliable.
Bioelectric impedance. This test uses a small, harmless electrical current to measure the electrical resistance of the body, based on the principle that lean body mass conducts electricity faster than fat body mass. Special "body fat" scales that use this principle in combination with your height and weight can calculate your body fat percentage. Results can vary with the amount of water in your body and are considered unreliable in people with obesity.
Underwater weighing. This test, based on the principle that fat tissue is less dense than muscle and bone, uses a special bathtub-sized tank to weigh a person underwater. That weight is then compared to the person's weight on land; a formula identifies the percentage of body fat that would account for the difference. Underwater weighing is considered the most accurate method, but it is generally available only at universities and research facilities.
Weigh Less
Two out of every three Americans are overweight. Excess weight can raise your risk of several chronic diseases, including heart disease, stroke, and certain cancers. Start lowering that risk with Weigh Less, Live Longer: Strategies for successful weight loss, a special report from Harvard Medical School that helps you personalize an effective weight-loss plan. Equip yourself with all the tools you need to lose weight safely and, most importantly, keep it off.
----------------------------------------------------------------------------------------
Click here to join the group Harvard Med: Talking About Health on Gather
You can find the following related articles on Gather:
A Practical, Achievable, and Durable Diet: The Garnick Portion Control Minus Method
Is there such a thing as a healthy snack?
Simple switches for healthy eating
This content is not intended to substitute for personalized medical advice, diagnosis, or treatment from your healthcare provider. Read our full disclaimer.
recommend this
email
print
link to this page
Comments: 7
i have been closly watching food intake since mid may now.
i have droped 11 lbs but have much more to go
Obesity is when excess body fat accumulates in one to where this overgrowth makes the person unhealthy to varying degrees. Obesity is different than being overweight, as it is of a more serious concern. As measured by one’s body mass index (BMI), one’s BMI of 25 to 30 kg/m is considered overweight. If their BMI is 30 to 35 kg/m, they are class I obese, 35 to 40 BMI would be class II obese, and any BMI above 40 is class III obesity. Presently, with obesity affecting children progressively more, the issue of obesity has become a serious public health concern.
Approximately half of all children under the age of 12 are either obese are overweight. About twenty percent of children ages 2 to 5 years old are either obese are overweight. Worldwide, nearly one and a half billion people are either obese or overweight. In the United States, about one third of adults are either obese or overweight. It is now predicted that, for the first time in about 150 years, our life expectancy is suppose to decline.
One solution beneficial in many cases of morbid obesity if one’s obesity is not eventually controlled or corrected is what is known as gastric bypass surgery. This is a type of bariatric surgery that essentially reduces the volume of the human stomach in order to correct and treat morbid obesity by surgical re-construction of the stomach and small intestine.
Morbid obesity is defined as one who has a body mass index of 30 kg/m or greater, and this surgery, along with the three other types of surgery for morbid obesity, should be considered a last resort after all other methods to reduce the patient’s weight have chronically failed. There are three surgical variations of gastric bypass surgery, and one is chosen by the surgeon based on their experience and success from the variation they will utilize. Over 200,000 gastric bypass surgeries are performed each year, and this surgery being performed continues to progress as a suitable option for the morbidly obese. There is evidence that this surgery is particularly beneficial for those obese patients that have non-insulin dependent Diabetes Mellitus as well.
Morbid obesity greatly affects the health of the patient in a very negative way. It has about 10 co-morbidities that can develop if the situation is not corrected. Some if not most of these co-morbidities are life-threatening. So the surgery to correct morbid obesity greatly reduces the co-morbidities associated with this type of obesity problem. Two percent of those who undergo this surgery die as a result from about a half a dozen complications that could occur. However, the surgery reduces the mortality of the patient by 40 percent or so, yet this percentage is debatable due to conflicting clinical studies.
Age of the patient should be taken into consideration, as to whether or not the risks of this surgery outweigh any potential benefits for the patient who may have existing co-morbidities that have already caused physiological damage to the patient. Also what should be determined by the surgeon is the amount of safety, effectiveness, and rationale for a particular patient regarding those patients who are elderly, for example.
Many feel bariatric surgery such as this should be considered as a last resort when exercise and diet have failed for a great length of time.
If a person or a doctor is considering this type of surgery, there is a website dedicated to bariatric surgery, which is: www.asmbs.org,
Dan Abshear