Disease of the month: Obesity

Obesity is a term used to describe somebody who is very overweight, with a lot of body fat. It is a common problem, estimated to affect about one in every four adults and about one in every five children between the ages of ten and 11 in the UK.

It is believed by some experts that obesity is responsible for more ill health than smoking, and we know that being significantly overweight is linked to a wide range of health problems.

It is also becoming an increasingly costly problem in our society and a recent government report claimed that obesity will cost the NHS £6.4bn per year by 2015.

Defining obesity
There are various ways in which to measure different aspects of obesity. They include Body Mass Index (BMI), skin fold thickness, waist circumference, waist to hip ratio and bio-impedance. The most widely used method is BMI. For most adults in the UK:

• a BMI of 25 to 29.9 means you are considered overweight;
• a BMI of 30 to 39.9 means you are considered obese;
• a BMI of 40 or above means you are considered severely obese.

It is interesting to note how these ranges differ in other countries. For example, a BMI of 23 may be deemed overweight in certain Asian countries.
BMI is not used to definitively diagnose obesity.

People who are very muscular sometimes have a high BMI, without excess fat. But for most people, it can be a useful indication of whether they may be overweight. It must be remembered that muscle does have a tendency of turning into fat if and when a regular exercise regime is not maintained.

Causes of obesity
Obesity is generally caused by consuming more calories (contained particularly in foods with high fat and sugar content) than we burn off through physical activity. The excess energy is then stored by the body as fat. Obesity is an increasingly common problem, because many modern lifestyles often promote eating excessive amounts of cheap, high-calorie food and spending a lot of time sitting at desks, on sofas or in cars.

Associated risks
Maintaining a normal body weight is important because, in addition to causing obvious physical changes, it can lead to a number of serious and potentially life-threatening conditions, such as:

Type 2 diabetes: Someone is more likely to develop type 2 diabetes if they are overweight or obese (with a body mass index of 30 or more). In particular, fat around the abdomen increases the risk due to the release of chemicals that can upset the body's cardiovascular and metabolic systems. About 10% of the NHS budget is spent treating diabetes and its complications.

Stroke: Extra weight makes us more likely to have high blood pressure and high cholesterol. Both of these conditions make heart disease or stroke more likely. Being overweight or obese can lead to a buildup of plaque in the arteries.

Eventually, an area of plaque can rupture, causing a blood clot to form. If the clot is close to the brain, it can block the flow of blood and oxygen to the brain and cause a stroke. The risk of having a stroke rises as BMI increases.

Coronary heart disease: As the body mass index rises, so does the risk for coronary heart disease (CHD). This is a condition in which a waxy substance called plaque builds up inside the coronary arteries. These arteries supply oxygen-rich blood to the heart.

Plaque can narrow or block the coronary arteries and reduce blood flow to the heart muscle. This can cause angina or a heart attack. Obesity can also lead to heart failure, where the heart can't pump enough blood to meet the body's needs.

Cancer: It is thought that more than one in 20 cancers in the UK are linked to being overweight or obese. Research has shown that many types of cancer are more common in people who are overweight or obese.

These include:

• breast cancer, in women after the menopause
• bowel cancer
• womb cancer
• oesophageal (food pipe) cancer
• gastric cardia cancer (a type of stomach cancer)
• pancreatic cancer
• kidney cancer
• gallbladder cancer

This list includes two of the most common types of cancer (breast and bowel cancers) and three of the hardest to treat (pancreatic, oesophageal and gallbladder cancers.) Being overweight can affect the risk of cancer because fat tissues in the body produce hormones and growth factors that can affect the way the body cells work.

Childhood obesity

Obesity experts say parents are struggling with a multitude of problems when it comes to their child's weight. They range from a lack of education about food, limited cooking skills, limited money to buy healthy food, long working hours, easy access to snack foods and pester power.

General wellbeing
Obesity can also affect quality of life and lead to psychological problems, such as low self-esteem or depression.

There are also some underlying health conditions that can occasionally contribute to weight gain, such as an underactive thyroid gland (hypothyroidism), although conditions such as this don't usually cause weight problems if they are effectively controlled with medication.

Treatment
The best way to treat obesity is to eat a healthy, reduced-calorie diet and to exercise regularly. To do this we should:

• eat a balanced, calorie-controlled diet as recommended by a doctor or weight loss management health professional (such as a dietitian);
• join a local weight loss group;
• take up activities such as fast walking, jogging, swimming or tennis for 150-300 minutes a week;
• eat slowly and avoid situations where you know you could be tempted to overeat.

When obesity is potentially life-threatening, weight loss surgery is available through the NHS.
In the UK, the most common type of bariatric surgery is a gastric bypass, which usually involves making the stomach smaller and bypassing part of the small intestine. Other types of weight loss surgery include a gastric band, which makes the stomach smaller, and a gastrectomy, where a part of the stomach is removed.

The cost of bariatric surgery to the NHS is thought to be about £6,000, but it is felt that the long-term savings outweighed this initial outlay. In new guidance, the National Institute for Health and Care Excellence (Nice) has lowered the threshold at which patients should be considered for an operation.

All people who are classified as obese who have serious weight-related illnesses could now be considered for the surgery.

Food for thought

So why don't people just stop eating foods high in fat and sugar if they know they can cause physical problems?

Scientists are still searching for the answers, but it appears that our brains have been wired to encourage the consumption of calorie-rich foods, even at the expense of good health. Quite simply, these foods bring us pleasure.

One recent study revealed that an area of the brain related to addiction and reward - the nucleus accumbens - lights up when a participant is shown calorie rich, fatty foods compared with healthy food.

Outlook

There is no ‘quick fix' for obesity. Weight loss programmes take time and commitment, but they work best when people are able to complete the programmes fully and are offered advice about maintaining the weight loss achieved.

The regular monitoring of weight, setting realistic goals, and involving friends and family with attempts to lose weight can also help. According to the NHS, another reason that obesity is on the rise is because unhealthy eating habits are often passed down through families, because of a lack of good food education.

Unless obesity is tackled, the government predicts that 60% of men, 50% of women and 25% of children in the UK will be obese by 2050.

Underwriting considerations

When an underwriter applies a loading for obesity the loading is for the additional risks associated with obesity, such as the additional risk of developing diabetes or having a heart attack.

A BMI rating table is used to equate the level of obesity with the extra risk, taking the client's age into account. l

Fergus Bescoby is underwriting development manager at VitalityLife