Four-year-old Johnny Collinson seemed too young to summit Mt. Rainier, and 14-year-old Hou Yifan didn't look the part when she became chess' youngest female grandmaster. But appearances can be deceiving, especially if you assume normal-weight people aren't at risk for complications associated with obesity, such as high lousy LDL cholesterol, diabetes and hypertension.

Being MONW - metabolically obese normal weight - isn't uncommon. Up to 20 percent of people diagnosed with diabetes are thin! And 37 percent of normal-weight adolescents have at least one risk factor for prediabetes - high blood pressure, high blood sugar or high LDL cholesterol.

Turns out, what determines lipid levels and some other risks associated with metabolic obesity is what you eat and how much you move around, not just how much you weigh. Case in point: 60 percent of North American adults are obese or overweight, but only 33.5 percent have lousy LDL levels.

So thin (or not), check your cholesterol levels at age 20, then again every five years. Check more often if you're a man over 45 or a woman over 50; if you've had an LDL cholesterol reading of 130 or more; or if your good HDL cholesterol level is below 40. Also, test glucose levels annually.

Get more active. Don't sit for more than two hours at a stretch. Add a 30-minute walk to your daily routine, aiming for 10,000 steps daily. Do 20 minutes of strength-building exercises two to three days a week.

Eat nine servings of fruits and veggies a day, only lean protein and 100 percent whole grains. You'll go from MONW to WOW!