Being overweight, in particular being grossly overweight or obese, is a major health problem. It carries an increased risk of heart attacks, stroke, blood clots, high blood pressure, diabetes, liver disease, lung disease, cancer, arthritis, infertility and premature death. Weight gain and obesity is a major problem in the UK. The latest NHS figures* show the proportion of adults who are overweight or obese has increased from 58% to 65% in men and from 49% to 58% in women between 1993 and 2011. While the proportion of obese adults has increased from 13% in 1993 to 24% in 2011 for men and from 16% to 26% for women. And the problem starts young. The latest figures show that around three in ten boys and girls are overweight or obese.
Are you overweight?
Looking in the mirror and getting on the weighing scales will no doubt reveal the most obvious symptoms of being overweight. Weight is assessed by taking a person’s body mass index (BMI) - this is your weight in kilograms divided by your height in metres squared. In other words, you can determine your BMI by dividing your weight in kilograms by your height in metres and then dividing the answer by your height again. Ideal BMI is 18.5-25. If your BMI is between 25-29 you are ‘overweight’. If your BMI is between 30-40 you are ‘obese’. If your BMI is between 30-40 you are ‘obese’. A person with a BMI over 40 is termed ‘morbidly obese’. BMI over 50 is malignantly obese.
Previously, most obesity experts considered that total body fat was the main predictor of weight-related disease. Now, it is thought that the location of fat is equally if not more important than total body fat. If you have more weight in the waist area (apple shaped) you are at greater risk of health problems than if your extra weight lies on your hips and thighs (pear shaped). For example:
- If you are a man with a waist measurement greater than 94cm you are at risk of developing weight-related health problems, and the risk is even higher if your waist measurement exceeds 102cm.
- If you are a woman with a waist measurement greater than 80cm you are at risk of developing weight-related health problems, and the risk is even higher if your waist measurement exceeds 88cm.
Although BMI is widely used for weight assessment, it is not appropriate for everybody. Athletes with a high proportion of muscle mass will have a high BMI but will have very little excess fat. Also, BMI is most applicable to the physique of people of Western origin, and may therefore under-state the health risks of people of Far Eastern origin who tend to weigh less and have a lighter body frame. Special charts are used to assess weight in children.
What causes people to become overweight?
The main cause is eating too much and moving too little. If you consume calories (units of energy in food) but fail to burn it off through physical activity, the calories get converted into fat cells.
Fast foods with a high saturated fat content and high calorie snacks are perhaps the greatest cause of obesity, particularly among children. These foods tend to give a short-lived energy boost, but have a very low nutritional value. Once the energy boost has gone the body craves another energy boost and, because the body still lacks the essential vitamins and minerals it was seeking in the first place, you feel that you want to eat again. This establishes a cycle of eating and craving that leads to weight gain. A balanced diet rich in fruit and vegetables, eaten at proper meal times, helps to break this cycle.
Over-eating is another cause of obesity. The part of your brain that controls appetite soon adapts to these large portions and does not send the message to tell you to stop eating. Meal sizes get bigger and bigger, and the weight piles on.
Meal-skipping is also likely to result in weight gain. US researchers recently used brain imaging to demonstrate that people who skip meals make bad food choices. After hours of deprivation the brain's reward centre goes into overdrive when it finally encounters the opportunity to eat causing us to opt for sweet and fatty foods.
Far from skipping meals, it makes sense to do the opposite - opting for many small meals throughout the day rather than one or two big binges.
Grazing rather than gorging boosts your metabolic rate, reduces hunger by stabilising blood sugar levels, and keeps your energy levels high.
Genetics may predispose a person to a slow metabolism (which means it takes longer to burn up calories) making it harder to lose weight but even in these circumstances, weight loss is still possible.
Some medical conditions (such as problems with your thyroid gland) may make weight gain more likely and certain medicines can cause weight gain as a side-effect. Common ones that do this include: corticosteroids (steroids), antidepressants and some oral contraceptives.
Being overweight can affect the way you feel on a daily basis and can put your long-term health in jeopardy. In the near-term being overweight may make you feel tired and affect your ability to sleep (often causing you to snore). It can also affect self-confidence.
In the long-term it increases your likelihood of problems such as heart disease, diabetes, back-pain and arthritis.