Introduction
Being overweight is now the most widespread, and rapidly increasing nutritional disorder in the developed world. It is a critical risk factor in the development of Type 2 diabetes, hypertension, and hyperlipidaemia, each of which is a major risk factor for coronary heart disease. It aggravates many symptoms of heart disease and increases CHD mortality 2-4 fold. In the UK, which has one of the highest coronary mortality rates in the world, 61% of men and 52% of women have a BMI >25 including 16% of men and 8% of women who have BMI >30. The prevention and management of overweight and obesity should be central to the primary and secondary prevention of coronary heart disease.
How are Being Overweight and Obesity Defined?
The World Health Organisation defines overweight using body mass index (BMI), which is body weight in (kg) divided by height (m). An acceptable BMI lies between 18.5 - 24.9. A BMI between 25 - 29.9 indicates overweight and those with a BMI > 30 are classified as obese. Waist circumference is a simpler measurement, which indicates the need for weight management and reflects coronary risk related to both overweight and a central fat distribution. A healthy waist measurement, reflecting low coronary risk, is below 94 cm (37 inches) for men and 80cm (32 inches) in women. Those with waist measurements greater than 102cm (men) and 85cms (women) have the greatest health risks, and should seek professional help.
Causes of Being Overweight
The aetiology of being overweight
Obesity is often simplified into the three components that govern energy balance - diet, physical activity and genes which determine individual predisposition by effects on appetite and metabolism. The interaction of these three factors leads to being overweight. Populations with food provision in excess of requirements, with >30% dietary energy from fat and low levels of physical activity are those with the highest prevalence of being overweight. The middle aged spread is an easy phenomenon to explain as the diagram below indicates. As we get older the body needs less fuel to function. We tend to keep eating the same as we have always done and the difference goes on as fat. There are two remedies to this. Firstly as we get older we should take more exercise and secondly we should eat less (portion control). It is common experience that the opposite in fact happens!! Unfortunately one needs to take an awful lot of exercise to burn off much fat so portion control is the most effective weapon.
Targets and Priorities for Weight Management
Major benefits of moderate weight loss (between 5-10% body weight), on reducing plasma lipids, blood pressure, and plasma glucose concentrations have been demonstrated with increased survival in overweight diabetics. It is critical to maintain these losses or to minimise regain of weight and this requires tong term management. Overweight patients with Type 2 diabetes, hypertension or hyperlipidaemia or who are current smokers should receive priority as they are at greatly increased risk.
Approaches to Achieve Moderate Weight Loss
Long term modification in diet to achieve and maintain moderate weight loss is essential. The emphasis needs to be on foods rather than nutrients. Bread, potatoes, pasta and rice, fruit and vegetables (at least five portions daily), should be the basis of the diet. Dietary fats, in particular saturated fats should be kept to a minimum.
Eating Behaviour
Disciplined shopping and the planning of meals are the cornerstones of good eating patterns. The overweight person requires the support and co-operation of their partner and/or family for success. Three regular meals each day, including breakfast, and fruit as snacks are also useful rules. Keeping a food diary is instructive and can be used to prompt appropriate changes.
Physical Activity
It is easier to maintain weight loss if regular; moderate physical activity is part of the lifestyle. However, as adipose tissue contains about 7000 kcal/kg, physical activity alone is seldom sufficient to lose much weight. The importance of activity alongside good dietary advice is to maintain weight loss and improve the health and well being of the individual. A physically active person is more likely to be at lower cardiovascular risk.
Medication
For the obese patient at high risk of cardiovascular disease and in whom dietary measures over several months have not produced weight loss of at least 10% of body weight, drug treatment may be indicated. Only one drug (orlistat) is licensed for long term weight management but another (sibutramine) which is licensed in USA and Europe, is soon to be launched in the UK. EU prescribing guidelines, supported by RCP guidelines, should be followed to restrict drug use to those patients who will achieve good long-term results (lose 2.5 kg on diet alone, and then 5% body weight in 12 weeks).
Being Overweight - A Growing Problem
It is one of the ironies of our time that while much of the world starves, Western nations are experiencing an epidemic of obesity. In the UK about 16% of men and 17% of women are obese (body mass index of 30 or more). The UK is about 12 years behind the United States where the problem is significantly worse.
Does this matter? Surely fat people are happy and active, like characters in a Beryl Cook painting? Or like W.S.Gilbert’s Pieman - 'He was plump and he was chubby, he was smooth and he was rosy, and his little wife was pretty, and particularly cosy, and he chirped and he sang and skipped about and laughed with laughter hearty - He was wonderfully active for so very stout a party.....’.
The reality is sadly different. People with a weight problem are often unhappy and suffer a variety of physical problems. So, is the problem as a result of too much food or too little exercise? The answer is a ‘bit of both'. Convenience foods are often high in fat or carbohydrate, the main culprits in causing weight gain. Busy lifestyles mean it is easy to ‘top up’ with a chocolate bar. The average British citizen consumes 23 lbs of chocolate a year! Most adults in sedentary occupations could survive on one meal a day.
What about exercise? Forty years ago only the wealthy owned cars. Now there are sometimes three or four cars in one family. Small shops have closed down and we are forced to go to ever bigger stores, by car. The young and energetic drive to the gym and then work out, then drive home. The increase in overweight problems amongst the young is a worrying trend. Many schools no longer offer the range of sporting activities which they used to.
As a GP, I am used to writing prescriptions. Do I have a prescription for the growing problem of overweight? No, but perhaps some ideas. Walking is the best exercise.If you are overweight, walking even short distances is better than nothing. Try some gentle work-outs at home; you will find that these will tone up your muscles and make walking less exhausting. If your joints are already a problem, join a swimming club or enrol on a course - it will be harder for you to justify not going if you have paid some money up front! Try not to sit down for too long-the urge to snack will creep upon you. Join a group - other people will help you. There is no one diet which suits everyone - the right diet is the one you lose weight on. Don’t give up-change is always possible. Accept that it is difficult and reward yourself for progress.
If you are not overweight? Know what the normal range of weight is is for your height and try to stay within this range.Once you start to become overweight the slippery slope gets steeper quickly. To paraphrase Mr. Micawber: ‘350 calories in, 340 calories out, disaster’. Avoid foods you know to be high in fat. You will enjoy them all the more as treats.
Above all, stay active in mind and body. Boredom is the greatest enemy.
Dr. D. Grant
Resources:
- Nuffield Bristol Obesity programme-Please contact Tania Blom She is a highly qualified Psychologist with links to the Nuffield Obesity programme.She can also help with anorexia and Bulimia
- Overeaters Anonymous: National helpline 07000784985
- Local group meets at the Friends Meeting House, Redland Road, Bristol Monday and Thursday at 7pm