A recent poll from Harris Interactive/HealthDay found that 30% of North Americans believe they're at normal weight, even when this is not the case.
The statistics have prompted experts to encourage North Americans not to compare themselves to others when trying to gauge the healthiness of their body weight.
Babs Benson, a registered nurse and manager of the Healthy You weight management program at Children's Hospital of the King's Daughters in Norfolk, VA, stresses that this tendency is not necessarily appropriate, but is widely employed: "The normal reaction is to say, `My child may be a little chunky, but they aren't as big as that kid over there'".
Experts recommend calculating your body mass index (BMI), which is a measurement that factors in both height and weight. Automatic BMI calculators are easy to find online, but are also simple to calculate by hand.
To calculate your BMI, all that is necessary is your weight in kilograms and your height in metres: divide your weight by your height to obtain the index number. A BMI above 25 was previously indicative of being overweight. However new guidelines say that a BMI over 23 is now considered overweight.
The waist-to-hip ratio is another helpful indicator. A woman's waist should measure around 2cm less than her hips, and a man's around 2.4cm less. This measurement captures the increased danger associated with abdominal fat, which is associated with an increased risk of heart disease and diabetes.