Federal guidelines establish the border between “fat” and “not fat” at a body mass index (BMI) of 25 for those 34 and younger, and 27 for those beyond age 34.

To compute yours, divide your weight in pounds by your height in inches. Divide this result again by your height in inches, then multiply by 705. For example, a 5-foot-4-inch person weighing 145 pounds would have a BMI of 25.

When your BMI reaches 27 it’s time to worry. If your BMI is 30 or higher you are at serious risk for heart disease, stroke, hypertension, diabetes, osteoporosis and other chronic diseases.