Obesity and Health
Australians, along with the residents of many other developed nations, are increasingly overweight and obese. Obesity is accompanied by several adverse health effects and chronic diseases such as high blood pressure, stroke, diabetes, high cholesterol, coronary artery disease and fatty liver disease.
Obesity is defined as a Body Mass Index (BMI) greater than 30 in adults and occurs via the accumulation of fats in adipose tissue. The most common reason for the over-accumulation of adipose tissue is over-nutrition (eating too much) and sedentary behaviours (not moving enough). When our intake of kilojoules is appropriate for our energy use adipose tissue plays an important role in energy balance.
A bit about BMI:
BMI can be calculated by dividing weight in kilograms by height in metres squared. For example the calculation for a person who weighs 74 kilograms and is 1.55 metres would look like this:
For young and middle-aged adults a BMI under 18.5 is considered underweight. Between 18.5 to 24.9 is the healthy weight range. A BMI between 25 and 29.9 is classed as overweight and >30 is obese.
There are of course exceptions to the BMI classifications for people who are very muscular (as muscle weighs more than fat) and, in general, BMI is most useful when looking at populations, however for most people working out their BMI can still be useful.
Why Obesity Can be Bad for our Health
Most adipose tissue is located just under our skin, however some is also found around our abdominal organs (visceral adipose tissue) and even around our hearts (epicardial adipose tissue).
Adipose tissue is not just an area for fat storage. Cells found in adipose tissue also secrete chemicals that influence the functioning of our bodies. The cells found in overweight and obese adipose tissue (particularly visceral adipose tissue) are often under stress and as a result they secrete inflammatory chemicals that can lead to all the adverse health effects associated with obesity. Adipose tissue in leaner individuals typically secrete a more balanced and anti-inflammatory cocktail of chemicals.
Waist measurement is a good indicator of visceral adipose tissue and since visceral adipose tissue is the greatest producer of inflammatory chemicals, can be a useful measure for assessing the risk of chronic diseases diseases such as diabetes and heart disease.
The World Health Organization has set the waist measurements which indicate an increased risk of chronic disease development at >94cm for men and >80cm for women.
To assess your own waist measurement take a measuring tape directly next to your skin between your bottom rib and the top of your hip bone. Breathe normally and do not compress the skin.
If you find, like a large proportion of people, that your BMI is in the overweight or obese range or that your waist measurement is above recommendations (or a combination of both) don’t despair.
We all know weight loss can be extremely difficult and getting into the healthy weight range and waist measurement for a lot of people is simply impossible, however modest weight loss of just 5 to 10% of body weight has been shown to cause a reduction in markers of inflammation. Other ways to reduce your risk of adverse health outcomes are to not smoke, exercise for at least 150 minutes a week and follow a healthy diet such as the Mediterranean Diet (and by diet I don’t mean a weight reduction diet followed for a short period of time, but a sustained lifestyle change).
Those worried about their weight and risk for chronic disease should consult a health professional for strategies to reduce their risk factors. This can include lifestyle interventions which also include expert nutritional counselling (dietitians and qualified nutritionists are great for this) and, for those with advanced risk, medications and/or surgical interventions.
Important Note for Parents
The best treatment for obesity is prevention. While it may be too late for many adults to ever reach a healthy weight range, and maintain that without superhuman effort, we can still prevent our children from going down the same path. Healthy eating in childhood and plenty of exercise and fresh air are the best things we can give our children to ensure their future health.