• Accurate measurements of body fat, mass and distribution require a variety of techniques and there is no one entirely satisfactory measure.

• A combination of measures is usually necessary to determine health risk.

• Validity, reliability and sensitivity of measures are an important indication of their worth.

• BMI is a good measure of body mass; waist circumference of fat distribution; skinfolds are useful measurements in the hands of experienced operators and with thon severely obese.

• New measures of central fat, such as abdominal diameter, may have important uses in the future.

Typically, the most commonly used measure of body fatness has been body weight. This is then compared with a table of ‘ideal weights’ prepared by life insurance companies on the basis of actuarial data, relating weight to the risk of an early death or to average weights in the population, and some measure of overweight calculated on the basis of population figures.

The advantage of weight is that it is a simple, accurate and reliable measurement. For individuals, significant changes in weight over the long term usually reflect significant changes in body composition. However, weight is often not a true reflection of obesity—particularly in those in the population (e.g. athletic males) who might have high body density due to muscular structure—nor a good indication of health risk, because measures of weight (in contrast to body fat distribution) do not correlate highly with illness risk. Height is, of course, a confounding factor and hence the calculation of body mass index, or BMI, which corrects for height, has become the norm.

More recently, it has been realised that BMI is also not always a good representation of fatness, again because of the bias against those with a high body density (i.e. those with a high fat free mass to fat mass ratio, FFM:FM). Hence there has been a recent move towards new measures of total body fat and fat distribution, including the better use of simple anthropometric measures such as height, weight and circumference measures. There has also been a move to develop cost-effective machines which accurately measure fat, in contrast to body mass.

*56\186\4*

In 1997, at age 33, Jack went for his first physical in a long time. The news wasn’t good. After years of not paying much attention to what or how much he ate, his weight had crept up to 245 pounds.

Worse, his cholesterol level had risen to 240—well above normal. Jack thought of his father, who had died of a heart attack at age 60. He didn’t want to risk the same fate.

“Like everyone, I needed motivation to change my lifestyle,” says Jack, a sales manager from Palm Bay, Florida. “My motivations were my cholesterol, my family history, and my three kids. I wanted to be around to see them grow up.”

Jack’s doctor wanted him to get his cholesterol level down within 2 months, and Jack rallied to the task. He gave up red meat, eggs, dairy products, and fast food. He learned new ways to prepare fish and chicken, instead of frying them. His diligence paid off: When he had his cholesterol level rechecked 8 weeks later, it had dropped to 160. As a bonus, he had lost 15 pounds.

That initial weight loss inspired Jack to make more dietary changes. Mayonnaise was out, mustard was in. Butter was out, replaced by a bit of olive oil or canola oil. Soda and fruit juices were out, water was in.

Restaurants presented a bigger challenge. Jack and his wife, Jen, enjoyed eating out. But Jack knew that the gargantuan portions were no good for his physique. So the two of them got into the habit of ordering one entree and an extra plate. Then they’d split the food between the two of them. “Most restaurants were quite accommodating, especially when I showed them my driver’s license picture so they could see how much weight I had lost,” Jack says.

How much did he lose? A total of 40 pounds in about a year. “My wife took off a few pounds as well,” he reports.

Jack is content at his current weight of 205 pounds, which he has maintained since 1998. To ensure that those extra pounds don’t come back, he and his wife have started a daily walking program. “And we still share our meals when we eat out,” he adds.

WINNING ACTION

Order one meal for two. Restaurant meals are the downfall of many weight-conscious people. The portion-control technique that Jack uses is a great one for a couple of reasons. First, it immediately cut your calories in half. And second, by eating with a fellow dieter, you have a j j* built-in weight-less buddy system.

*48\89\8*