Print

Introduction Obesity is not one disease but a number of interconnected diseases and prob­lems that come about through the interaction between our ge­ne­tic makeup and our environment. It runs in families. Between 25 and 40% of our weight is determined by our genes and what goes on in our cells. Genes influence not only the ways we take in nutrients and excrete them but also the way we store our fat. The rest of our predisposition to fat is dictated by environmental ­factors, such as our access to unhealthy food, the portion sizes we eat, and the ways we may use food as an emotional crutch. “Obesity” and “overweight” are often used interchangeably ­because the same health risks are attached to both of them. I prefer to use the term “overweight,” which gives us an understanding that our weight is modifi- able and relegates “obesity” to the extreme end of too much weight, often where drastic surgical intervention is necessary to achieve real change. The degree of risk is greater the more overweight or obese we are. Body mass index (BMI) is the current mea­sure­ment used to determine ­ w hether we are overweight or obese. BMI is calculated by dividing our weight in kilograms (kg) divided by our height in meters squared (m2). The normal range for BMI is 18.5–24.9 overweight is 25–29.9 obese is 30.0–39.9 and extreme obese is ≥ 40. To calculate your own BMI, The Centers for Disease Control and Pre- vention has an easy-­to-­use BMI calculator (Adult BMI Calculator).1 Changing our weight involves a lot of mea­sur­ing to see how we pro­ gress for example, we mea­sure our weight, the calories (energy content) of what we eat, how long we undertake physical activity, and so on. The units used for the mea­ s ure­ m ents depend on which side of the Atlantic you live. In the United States, ounces, pounds, inches, feet, and calories are the common mea­sure­ments. However, a lot of the research is conducted in kilograms, grams, centimeters, meters, joules. It may be confusing,