Our children are affected too. In North America, some of the fastest-rising obesity rates are among children. Overweight adolescents are developing serious health conditions once seen only in older adults. For instance, teen girls and boys are developing type 2 diabetes 30 years earlier than they should. The disease has been diagnosed in children as young as nine.
It is no surprise that overweight kids are expected to have shorter lives than their parents. Higher body weights increase the risk of death from many causes. These kids will also suffer from prejudice and discrimination.
Obesity is not just a personal issue, but concerns public health and society. It has the potential to weaken our economy, overwhelm our health care system, and shorten our lives.
Body fat and weight result from a complex interaction between genes and the environment. Two medical terms are used to describe extra weight – ‘overweight’ and the second, more serious ‘obesity.’
Weight is measured using the body mass index, or BMI. This is a simple ratio of weight divided by height (weight in kg ÷ height in m2 or see ww2.heartandstroke.ca for a BMI calculator). BMI is a fairly reliable measure of body fatness that can be used in anyone.
|Overweight and Obesity using Body Mass Index (BMI)|
|Underweight||Less than 18.5|
|Normal||18.5 - 24.9|
|Overweight||25.0 - 29.9|
|Obesity||I||30.0 - 34.9|
|II||35.0 - 39.9|
|Extreme Obesity||III||Equal to or greater than 40|
Overweight is defind as a BMI of 25.0 to 29.9 kg/m2. Obesity is a BMI of 30 kg/m2 or greater.
Studies have linked health problems and death to BMIs above 25 kg/m2. By the time a BMI of 30 kg/m2 (obesity) is reached, 75 per cent of people have already developed health complications associated with obesity.
Further studies show the risk for type 2 diabetes increases by about 200 per cent in overweight men and almost 800 per cent in overweight women. With obesity, the risk of diabetes becomes even more dramatic. The risk rises to 700 per cent in obese men and 2,700 per cent in obese women!
Recent data from Ontario shows that the rate in cases of diabetes have increased greatly during the past 10 years. By 2005, they had already passed the global rate predicted for 2030. This explosion in obesity rates is seen as the cause for an epidemic of type 2 diabetes.
Health risks increase greatly with greater body fat. The position of fat in the body also matters. Fat in the abdomen, or belly fat, carries greater health risks than fat in outer regions such as the buttocks and upper thighs.
Belly fat is not just quiet storage of energy. It produces a variety of messengers that cause great confusion in the body. Increased belly fat abnormally changes sugar and fat metabolism. This in turn can result in high blood glucose (sugar) and fat, diabetes, high blood pressure and cardiovascular disease.
Abdominal obesity alone can predict risk, even when BMI is not greatly increased. A Canadian-led international study has been done on heart disease risk factors that are within our control. It involved 30,000 people from 52 countries. This study found that abdominal obesity itself can predict a heart attack. Eight other major risk factors exist, including high cholesterol levels, diabetes, smoking, high blood pressure and being physically inactive.
Canadian clinical practice guidelines now recommend that health care providers measure waist circumference as a vital part of assessing health risks. This is as important as measuring blood pressure and heart rate. As we age, waist circumference plays a greater role in estimating risk for diseases related
to obesity. The cut-off values are somewhat arbitrary, alerting the health professionals that their clients above the cut-off values are at much greater health risks. In general, the higher the waist circumference measurement, the greater the health risks.
Ethnic background also plays a part. In some groups, especially South Asian and Chinese, waist size predicts risk better than BMI does. This is particularly true with type 2 diabetes and cardiovascular disease. As a result, recommended waist size measurements vary.
Recommended Maximum Waist Measurement
|European||greater than 94 cm (37 inches)||greater than 80 cm (31.5 inches)|
|South Asians, Chinese||greater than 90 cm (35 inches)||greater than 80 cm (31.5 inches)|
|For East Mediterranean, Middle East (Arab) and sub-Saharan African, use European cut-off points.
For South and Central American and Japanese, use South Asian and Chinese cut-off points.
Treating overweight and obesity is a two-step process involving assessment and control. First, your waist circumference and BMI will be measured. Use these numbers as a guide to watch how your weight loss progresses. Your doctor will talk to you about how much weight you need to lose and other health risks.
Managing weight involves both losing extra pounds and staying at a healthier size. You may need to take other steps to control associated risk factors. Your doctor or other experienced health professional (dietitian, nurse, pharmacist) can provide useful advice. Hospital or community programs may also help. In some cases, preventing further weight gain can be a goal. As obesity is a chronic disease, successful treatment often requires lifelong effort.
Unfortunately, there is no specific way to lose just belly fat. Losing weight in a healthy way also takes time. To begin, try to lose five to 10 per cent of body weight over six months. Once you reach this goal, you can attempt further weight loss if necessary.
After six months, the rate of weight loss usually drops off and weight may not decrease. You are now using less energy at a lower weight than you did when you were heavier. If you want to lose more weight, your diet and exercise level can be adjusted. Otherwise, start using a weight maintenance program or you will be likely to regain the lost pounds. Your program should include healthy eating, regular physical activity, and behaviour therapy to overcome unhealthy habits.
Even if you are unable to reduce your weight enough, preventing further weight gain is important. You may also need to participate in a weight management program. Keeping in touch with your doctor as you improve your diet can bolster your efforts. Your doctor may take steps to reduce any other cardiovascular disease risks.
Increasing physical activity is an important part of a weight loss program. However, it will not greatly increase the amount of weight lost over the first six months. In order to lose a pound of fat, you have to burn 3,500 calories. This translates into about half an hour of daily exercise, such as brisk walking or cycling for three weeks. Most weight is due to eating fewer calories. Consuming 100 fewer calories each day (a glass of pop, a pastry or even an apple) can help you to trim off 10 pounds in a year. Regular physical activity helps maintain weight loss. Exercise also reduces your cardiovascular and diabetes risks in a way that weight loss alone cannot do.
Most obese people should start slowly with physical activity. Gradually increase the intensity. Exercise can be done all at once, or at various times throughout the day. Aim to accumulate a total 30 minutes of physical activity, such as walking, five or more days of the week.
Losing one kilogram (2.2 pounds) of body weight usually also reduces waist circumference by about a centimetre (half an inch). This in turn lowers a heart disease risk by two per cent.
Studies have proven that modest weight loss prevents or delays the development of type 2 diabetes. Losing a kilogram a year, over three to four years, may reduce your risk of developing diabetes by as much as 60 per cent!
Setting realistic goals for slow, steady weight loss is the recipe for long-term success. Regular physical activity and healthy eating practices keep weight off and prevent regain.
If you are unable to achieve your desired goals with lifestyle changes, drug therapy or surgery may be useful options. Recent studies have proven that in such cases, weight loss surgery saves lives and reduces the risk of disease. By losing weight, you truly can gain your continued health.