Cheryl Richardson is what nutritionists might call a "hard loser"—someone who cuts calories and boosts exercise without seeing results when they step on the scales. A 54-year-old stocks-and-commodities trader from the Dallas area, Cheryl has been overweight since childhood. Countless diets over the years provided her with a history of yo-yo body weights but no long-term solution to personal weight management. Ten years ago, she became obese during a stressful time and then found it nearly impossible to lose the weight.

She finally enrolled in a weight-management program, hoping to lose 50 pounds. One year later and 20 pounds lighter, what she learned from the program (at the Cooper Institute in Dallas) has made her healthier, stronger and happier, even though she failed to reach her personal weight goal.

Bathroom scales don't lie, but they tell only partial truths. We depend on them too much for a report that doesn't reveal important information about real fitness and the likelihood of preventing disease. Body weight is but one measure of health, not the ultimate indicator that figures so prominently in most people's minds.

In Cheryl's case, being obese was just part of a significant constellation of factors that added up to a serious health condition called metabolic syndrome, which affects at least 20 percent of Americans, or 47 million adults.

Metabolic syndrome is diagnosed when a person exhibits three or more of the following risk factors: waist measurement more than 40 inches (men) or 35 inches (nonpregnant women); HDL (good) cholesterol less than 40 (men) or 50 (women); blood glucose (sugar) levels at or exceeding 110; triglycerides of 150 or higher; blood pressure of 130/85 or more. The diagnosis is an indication of compromised health: metabolic syndrome carries an increased risk for diabetes, heart disease and premature death.

Cheryl's family history further confirmed the profile of metabolic syndrome. Two of her sisters have diabetes, as does her father, who also had bypass surgery for clogged coronary arteries. Cheryl wanted to lose weight to improve her appearance, but she also wanted to reduce her risks for these diseases.

Despite not reaching her weight goal, Cheryl Richardson had much to celebrate one year after beginning the program. She had reversed her diagnosis of metabolic syndrome by getting her blood pressure from 139/89 down to 127/78. At the same time, she had lost eight inches off her waist and dropped over 50 points in triglycerides. She now has more energy and a new attitude.

Cheryl's program is simple but steadfast. She eats more whole grains, vegetables and fruits and less red meat, but does not obsess about her food. Most important, Cheryl feels, is her ironclad rule: to walk for an hour five mornings a week.

"I don't feel like I'm denying myself anymore. I'm finally at peace with food," she says with conviction. "It's the total package of fitness and food. I've never felt this good. It comes down to smart choices, portion control and being faithful to my exercise program." Like many people who report long-term weight control, Cheryl has chalked up double the recommended walking time (the usual government guideline is 30 minutes of moderate physical activity on most days of the week).

With obesity widespread in our society and metabolic syndrome a new reality for one adult in five, Cheryl's case is instructive. Her weight didn't plummet, but her vital measurements of metabolic fitness all improved—without the use of medication. At the same time, her risks for both diabetes and heart disease were reduced. Her health outcome was less visible but more important than her weight loss.

Bathroom scales alone can't reveal metabolic syndrome. Anyone concerned about this modern-era plague needs to see a doctor for a checkup and a go-ahead to exercise. For the rest of us, an updated perspective may be in order: healthy bodies come in myriad shapes and sizes. Thinness and true fitness are not always the same thing.