Saturday, January 23, 2010
Obesity Is Not A Disease
Obesity is much in the news, yesterday because surgeons are complaining that the NHS isn't making provision for many more thousands of gastric-banding operations annually.
Without question obesity is epidemic. Without question obesity shortens life, reduces the quality of life, and inflicts huge costs on our health services.
So what might be a physician's response? The only realistic advice is depressingly ineffective.
Never let yourself get into this condition.
The hard fact is that established obesity is very difficult to reverse. Most obesity we see has developed over many years. The daily habits which have caused the obesity are difficult to change, and any change has to be determined and permanent. Almost all obese patients find this impossible, not least because weight loss is always painfully slow. And the change in habits has to include family and friends - which would be remarkable if it could be achieved.
As I was taught, in language too plain for today:
Look at the family of a fat patient and you will find a fat spouse, fat children, and a fat dog.
Why is dieting so slow to reduce weight? I think the answer lies in energy balances. One gram of fat produces about 9 Calories, so 1 kilogram of fat is 9 kiloCalories, enough energy for 3 days manual labour.
Fat is an insulator, so an obese person needs fewer Calories to maintain body temperature. Obesity causes immobility, consequently the energy demand for activity is also reduced. Many obese people need fewer than 1,500 Calories daily.
So a week of total fasting, water only, might burn off just 1 kilogram of fat.
[And the first few days will see spurious weight loss: fasting causes total body water to be reduced.]
For most people a 1000 Calorie diet is very restricting, but achieves a daily energy deficit of a few hundred Calories at best. Some severely obese people may still be in positive energy balance even at this level of dieting.
No wonder people get disheartened and miserable, give up, eat for comfort.
In the past we sometimes admitted obese people for very strict dieting under supervision. In a warm ward, in bed or sitting most of the time, surrounded by kindly other patients with chocolates, admission was doomed management. If some reduction was achieved, then it was common to find the weight regained at the first follow-up.
'Weight-watchers', or similar group therapy, has the best chance of success, if people are sufficiently motivated. The same applies to alcoholism: 'Alcoholics Anonymous' does great work in its equally difficult specialty.
There is a genetic element in obesity, in that some people become obese especially easily. Surveys have shown that the obese often eat less than matched, lean people. Even so, the obese are taking more than they can use. There's no justice in nature.
Women are at increased risk of obesity; so are African, Arab and Asian people living a 'western' lifestyle.
In Britain the prevalence of obesity has an inverse relation to income.
'Maturity Onset' diabetes mellitus is associated with obesity. The diabetes causes obesity, and the obesity makes the diabetes more severe. I suspect anyone will become at least chemically diabetic if weight increases enough.
The converse is true: weight loss reduces the diabetic state, in the earlier stages at least.
Sulphonylurea drugs may be prescribed when dieting fails to reduce the blood glucose values. These drugs increase insulin secretion. Dieting becomes less important in diabetic control. They improve the blood glucose chart at the expense of making weight loss even more difficult.
Other than this type of diabetes, diseases causing obesity are rare. Food intake in excess of need is by far the most prevalent cause of obesity.
And what is eaten is not so important as total energy intake. Fat and sweet foods are rich sources of energy, and so especially fattening.
There is no magic pill which achieves weight loss without dieting. A safe, effective slimming drug would be hugely profitable to its inventor, but the prize remains untaken, and is likely to remain so. We do now have a number of drugs which may be used in selected cases to increase weight loss by dieting. I have no experience of their use, so I will not comment further.
Surgery has its indications, but it is a policy of despair. Obese patients are poor candidates for anaesthesia and surgery. Complications are more frequent, and some will be severe, even fatal, for the patient. For surgeon and hospital litigation is likely to be more frequent - we heard yesterday of claims increasing after obesity surgery.
Procedures include excision of fat deposits, especially abdominal, and liposuction. Other procedures aim to reduce the capacity of the stomach, or reduce the absorption of food in the small intestine. Gastric banding can be done laparoscopically, and is a favoured operation at present.
Operations to bypass a length of small intestine were popular at one time, but a serious risk of late septicaemia became apparent.
All operations on stomach or intestines seem to work by suppressing appetite. In selected patients results can be good, but surgery is a drastic means of enforcing dieting.
So my advice to an obese person is this. Don't consult me. I can only tell you what you know already, that you are eating too much; your only hope of remedy is in determined dieting and exercise. If you want pills or an operation consult someone much younger and more enthusiastic. Don't go to a private practitioner: the prospect of fees may distort the judgement and advice of a saint.
Homo evolved in a hungry world. Our genes create us with a thrifty metabolism; we are poorly adapted to food abundance. War-time rationing proved to be good for the nation's health.
My generation may be the first never to have known hunger in Britain: compare our stature with our parents', and our childrens' with ours. But epidemic obesity warns against excess and complacency. We are now rich enough to waste food on a grand scale - truly we have grown decadent.
Those whom God wishes to destroy he first makes rich.