Nearly half of all adults and one-quarter of our children are over – weight. Being overweight can lead to serious health problems including high blood pressure and high cholesterol levels and an increased risk of type 2 diabetes, gallbladder disease, back and joint pain, and sleep disorders. In addition, women who are severely overweight (obese) are also more likely to develop breast, uterine, endometrial, and ovarian cancer. Obese men are at increased risk for colon and prostate cancer.
Being underweight can also cause health problems including bones that are thin and brittle, fertility difficulties, decreased ability to fight illnesses and infections, hair loss, and feeling cold all of the time.
For the sake of your health, you should aim for a healthy weight. A healthy body weight is not a single target number; it is the range in which the risk for weight -related health problems is lowest for a particular height and body build. There are several methods used to determine if a person’s weight is in the healthy range. The most common methods are the body mass index, hip- to-waist ratio, and waist circumference.
Body Mass Index
The body mass index (BMI) assesses body weight relative to height. You can calculate your BMI by taking your weight in kilograms and dividing it by your height in metres squared (BMI = kg/m2) or your weight in pounds divided by the square of your height in inches and multiplying that number by 704.5 (BMI = Ib/in2 x 704.5). But you don’t need to do the math yourself. You can check your BMI on a standard BMI table found in many pharmacies and medical offices. If you have access to the Internet, there are many interactive BMI calculators that will do the math for you after you enter your height and weight.
Once you know your BMI, you can use it to help determine how healthy your weight is in relation to your height.
BMI below 18.5 is considered underweight.
BMI between 18.5 and 24.9 is considered the normal, healthy range.
BMI between 25 and 29.9 is considered over¬weight.
BMI over 30 is considered obese.
The BMI is only one indicator of a healthy weight. It has limitations and does not apply to children, pregnant women, or people with very muscular bodies. If your BMI falls outside what is generally considered healthy, ask your doctor what would be a healthy range for you.
Fat stored around the abdomen (the “apple¬shaped” body) raises the risk of cardiovascular disease more than fat stored in the hip area (the”pear-shaped” body), so the hip-to-waist ratio (HWR) can be a useful tool in determining your risk of weight-related health problems.
To calculate your HWR, measure your waist at the smallest part-generally a few centimetres above your navel-then measure your hips at the widest point, including your buttocks. Now divide your waist measurement by your hip measurement to determine your hip-to-waist ratio.
Women with an HWR greater than 0.8 and men with an HWR greater than 1 .0 have a higher risk of developing heart disease and type 2 diabetes and should try to reduce their abdominal body fat.
Another easy tool for determining if your weight is in the healthy range is the waist circumference (WC). A WC of 88 cm (35 in.) or more in women or 102 cm (40 in.) or more in men carries a higher risk for health problems.
One of the keys to achieving and maintaining a healthy weight is portion control. A number of studies have shown that many people under¬estimate the number of calories they consume daily, primarily because they don’t understand how much is in “a portion.” Here is a practical way of estimating the size of a portion of some common foods.