Those who know me may have observed a change in my appearance during the past two and a quarter years. I have been on a diet that has taken me from being a very fat man indeed to a man of entirely normal size and shape. This is a remarkable achievement, but it is not something I have before now been inclined to discuss. Had it been an intellectual achievement—learning Japanese or Sanskrit, for example, or completing the symphony I began when I was 17—those around me would have heard no end about my progress. But controlling my weight is another matter. Though I was prepared to joke about it, being fat was something I always found hard to discuss. It affronted my self-respect. It aroused my hypochondria. It was the one failure of the self control I practised in all other things. Of course, I discussed my progress and ambitions with Mrs Gabb and with Mr Huet, who has known me since September 1971. But I did not discuss these matters with anyone else, and I responded to most comment with a few vague generalities that indicated an unwillingness to say more.

However, this is not something that can be ignored. The change in my appearance has been so complete that those who have not seen me for a few years are now astonished—astonished and often worried that diet and exercise cannot in themselves have accounted for the change. Also, with the controversy over the Atkins Diet, talk of dieting has become not only respectable for the moment, but even fashionable. Also, I have been in close conversations for the past few months with David Carr, who is also on a diet and who seems to regard me as something of an inspiration to his own efforts. I suspect it will help me if I now speak openly, and it may help others. So I will come out of the closet and confess: I have a problem with my weight, and I am on a diet. Let me specific.

The crisis came on the middle Saturday in April back in 2001. Mr Huet had come round to dinner, and I had eaten heartily of the food cooked by Mrs Gabb—cream of mushroom soup, roast lamb with garlic and potatoes and vegetables, followed by ice cream and apple crumble: as you may know, I am blessed or cursed with an almost perfect memory for dates and events. Toward the end of the evening, Mr Huet persuaded me onto the electronic scales in our bathroom. With digital accuracy, my weight was revealed to be 22 stones and 6 pounds—for my American readers, one stone is equal to 14lb: for my foreign readers, one pound is equal to 454 grammes.

I was shocked and frightened. For anyone, this was an alarming weight. For a man of five foot nine inches, it was even worse. I made a quick calculation of my body mass—divide your weight in pounds by the square of your height in inches and then multiply by 703—and the result was 46.365. According to the insurance companies, any more than 25 is overweight: any more than 40 is morbidly obese. To use a grim cliche, I had for many years been digging my own grave with my teeth.

Sat in my car after I had taken him home, Mr Huet tried to comfort me. I was still in excellent health, he told me. My heart rate and blood pressure and all other vital measurements were surprisingly normal. This could not last, bearing in mind my advancing years, but determined action now could solve the problem and give me a normal life expectancy. I heard him, but was too utterly cast down with fear and shame to give more than an intellectual assent. Even so, I promised to do something. I had had similar conversations with Mrs Gabb over the years, but nothing had come of these, and I really doubted if anything would come of this.

For the next few weeks, nothing did come of it. I carried on as before—cheese on toast for breakfast, tuna and mayonnaise roll for lunch, pasta with olive oil and cheese or fried turkey with rice or whatever for dinner; and several snacks of flapjacks and peppermints during the day. Then, on the last Sunday in April, I lay in bed and prayed for strength. When I woke up, I felt comforted and determined. Some will say that God heard me and took pity, others that I had altered my own state of mind. But the diet began. I am a confirmed diarist and collector of personal information. I opened an Excel spreadsheet, making entries as and when I felt inclined. Between then and now, my records show the following loss:

When I told Mrs Gabb I was on a diet, she smiled and wished me luck. She had heard too much of this before. When I had lost my first stone, she tried to look impressed, but was unable to find any change in my appearance. Another few stones, and she began to worry for my health, insisting I should have myself looked at by the doctors. Eventually, she accepted the fact, and now proudly takes me out to buy normal clothes. When I was very fat, shopping for clothes was always an ordeal. It was a matter of luck whether Marks and Spencer would have large enough sizes; and I felt acutely embarrassed to stand there trying on jackets and sweaters, only to see how they strained across my belly, or as I crept into the changing rooms and tried to heave myself into the largest trouser size. All that is now in the past. I weigh just over 12 stone, and plan to stay there.

However, the diet is not over. It will never be over. Though I hope it will be the last diet, it was not—my oldest friends will have noticed—the first. I have been here before, and have never stayed here.

I was a fat child. I had asthma, which made hard exertion difficult. And I was studious, spending much of my time sat with a book. It was an unfortunate combination. Between the ages of 12 and 18, my weight in stones kept exact pace with my age in years. I was not wholly inactive. Though I avoided all field sports at school, I did enjoy swimming; and I would spend every summer all day in the open air pool near my home. But while enough to strengthen my lungs and give me a powerful body, it was never enough to reduce my weight. At school, I was called "Flabby Gabby", and Mr Huet would delight in turning out caricatures of me—he excelled in the arrangement of dimples. Every so often, I would resolve to go on a diet, but never get round to starting. Then, when I was 18, I did go on a diet. During the next six months, I lost four stone. Then I stopped, and the weight went quickly back on.

During my first two years at university, my weight first stabilised and then began to drift down. My friends told me that I was at last burning off my "puppy fat". Encouraged, I began another diet in July 1981. I started at 17 stone. By Christmas, I was down to 11. For the next five years, I settled into a regular scheme —gaining a few stones in the winter, losing them in the summer, and averaging 13 stone. Though far from stable, my weight was under reasonable control.

This ended early in 1986, when I began to gain weight again. By the end of 1988, I was up to 18 stone. Then, in November 1990, Mr Huet—it is usually he who forces my hand in these matters - persuaded me onto some scales in Boots. With clothes, I weighed 20-12. There followed the usual laments and promises. But these came at another opportune moment. Within 18 months, I was back down to 12 stone. Then from the middle of 1992, the resolve lapsed, and I had begun the steady climb to where I found myself in April 2001.

So far, I have given little more than a record of weight gained and lost. More interesting for my readers, I am sure, is why these changes happened, and how I have tried to control them. To the first, I cannot give a satisfactory answer. I watched a television documentary about a year ago in which various doctors insisted that no one had a predisposition to be fat, and that everyone had the same nutritional requirements. I am not able to contest the statistical and physiological evidence they presented in support. But I do reject their conclusion. Anyone who knows me will agree that I have never been greedy or even particularly inactive. Dr Tame, who knows me well, will confirm this. I have watched televison interviews with people of around 25 stone, and always been amazed at the vast quantities of food they needed to keep themselves there. I really doubt—and self-deception is not among my failings—that I normally ate more than about 3,000 calories a day. For a normal person of my habits, that was enough to produce a slow increase in weight over the years, but not the growth that did occur.

During my first nine years with Mrs Gabb, I ate the same as she did—I often ate less, as she has always enjoyed more snacks. But she gained not a pound, and I gained ten stone. I swam, I walked, I cycled, I took stairs rather than lifts. Yet I grew enormous. I can only conclude that I do not need so much to eat as most other people. I will never deny my good fortune to be born an Englishman: with the usual one unmatchable exception, mine is the greatest nation in history. But I am probably better adapted in the physical sense to being a hill farmer in one of the less fertile areas of the Eastern Mediterranean. The same applies to most of my relations. My mother, for example, has been fighting the flab since long before I was born. Whatever the experts may presently insist, I am convinced that I have a genetic predisposition to making and storing fat.

Added to this, of course, is my state of mind. I am a comfort eater. When I am depressed or under some other strain, I have a tendency to eat. Some find refuge in drink or drugs, others in sex or gambling or whatever. I eat. In 1986, I fell into a mild depression. I was dissatisfied with my progress in life. Old university friends all seemed to be racing ahead—money, marriage, sometimes fame. I had none of these. I was drifting. I persuaded myself into a low state of mind, and when I allowed myself to grow fat in consequence, this helped keep me there. At the end of 1990, I resolved to break out of this cycle. I resigned from the Civil Service and began to make a name for myself as a political extremist. Losing weight became part of this new way of life.

When I came back to England from Slovakia, I found myself with a mass of external problems. I had a wife to support and what seemed a mountainous bill for income tax—it took years to pay off. I also had very limited means of making money. I had few contacts in teaching and limited experience. Nor was there much paid consultancy. I dreaded bills, and lived in a state of permanent nervous apprehension. I put on weight, and, again, this kept me depressed even after the external problems had been solved. That I had become an embarrassment to Mrs Gabb only made me feel worse. How at my best she puts up with me puzzles me. But women are a mystery. The only one I think I really understood was Victoria, and she was a dog. But no matter this. It was the great success of my Candidlist project, I am convinced, that gave me the moral strength to begin another diet.

So much for the causes. Now to the treatment. My settled belief is that losing weight requires less eating and more exercise. I believe fundamentally in calory restriction. I also find it convenient for me to cut out most fat. For two years now, my diet has largely consisted of bread, potatoes, rice, pasta, fruit, raw vegetables, and fish, with small amounts of meat—and limiting all to between 1,500 and 2,000 calories per day. It works for me.

I readily accept it is not the only way, and that it may not work for others. I have been following the controversy over the Atkins Diet, which is the exact opposite of my own. That requires the virtual elimination of everything I eat, and allows unlimited amounts of animal fat and protein. When I first heard about this, I was sceptical. On the other hand, similar low carbohydrate diets have been around for centuries, and these do seem to work. One of my colleagues began the Atkins Diet last Easter. Since then, he has lost 20lb, and looks and feels much better for it. That all the experts condemn the diet as dangerous is probably of no consequence. They change their own advice every few years. All that remains constant is their dislike of anything approaching self help. They are less concerned about what they recommend than about their sole right to recommend—or, indeed, to compel.

But the choice is not only between low fat and low carbohydrate. There are claims—and I find them quite probable—that the Mediterranean diet of bread, olive oil and wine also prevents or reduces obesity. It seems to have done the Greeks no harm; and little though I regard the present inhabitants of the Achaean Peninsula, they are not generally fat. And this is a diet high in both fat and carbohydrate. Though I am not sure if he has tried it himself, Dr Tame told me the other evening over dinner about a diet that involves eating only raw food—and that includes meat and fish. He knows someone whose cancer went away after starting this diet. Mrs Gabb then spoke about a Slovak actor whose stomach cancer went away after a year of eating nothing but goat cheese and raw vegetables.

Whatever the experts may insist, I do not believe we know much about nutrition, or about the effect of specific kinds of nutrition on specific races or specific moral dispositions. Tiberius once said that anyone who did not know what was good for his own constitution by the age of 30 was a fool. He was probably right, and the emphasis must be on "own constitution". The human body may be a machine, but it is not at all a standardised machine.

One thing I do believe of general value, though, is that dieting is not a short term cure. It is not like taking a course of antibiotics. I was fat because I cannot digest food in the same way as most others do. I must therefore look forward to a lifetime of carefully watching what I eat. It is not enough to cut out fat while losing weight: it is necessary also to stay with the diet for life - though, perhaps with a slight increase in the number of calories so that the weight can be kept stable. Discussing some of this with David Carr, we are agreed that a tendency to put on weight is best regarded as a medical problem like diabetes. It requires permanent changes in lifestyle. If she wants, Mrs Gabb can eat a full English breakfast with toast and marmalade, followed by coffee with whipped cream, and a snack an hour later of kettle chips and cream cheese. Without regular meals, she loses weight. I am not nor ever can be the same. Fried food is not good for my waistline. Also, it has just occurred to me, it gives me indigestion.

Something else of general value is to insist that being fat is a bad thing. I remember reading Susie Orbach and Naomi Wolff and other demented feminists to the effect that body size and shape are purely matters of culture, and that our own preference for a trim figure is both unnatural and a means of imposing shame and guilt on women. Women, they say, look at the delightful creatures shown in the television and poster advertisements and are thereby kept in patriarchal slavery by the resulting loss of self-respect. More recently, this analysis has been applied to men. I think it is here supposed to be capitalism in general that oppresses us.

This is all nonsense. No culture that has found obesity attractive has produced anything of physical or moral beauty. The greatest civilisation that has ever existed—and let us forget any claims about our own: we are nothing by comparison—gave us not merely the Homeric Poems and the Parthenon and the philosophies of Aristotle and Epicurus, but also exemplars of at least male beauty reaching from the statue of the Critian Boy of the 6^th century BC to the statues of Antinous of the 2^nd century AD. Those are the standards by which we should think to judge ourselves.

This aside, those who conform most closely to the recommendations of the insurance tables live longer on the whole and enjoy better health. They also tend to have more friends and make more money. No amount of complaining can alter these latter facts—nor should it.

The Sunday before last, I made an important discovery. We had been invited to dinner with some friends. I sent an e-mail hesitantly asking that I should be offered a low fat menu. I added that this would only be convenient, and that it was not required should it give any trouble. Within minutes, I had back a friendly assurance that my wish would be his command.

These are not matters to be covered up, I find. They can be discussed, and most people seem happy to lend a hand. My readers may have found this a tedious issue of Free Life Commentary, and some may even be wishing I had kept to my more usual rant about what an evil man is Tony Blair—traitor, petty tyrant, warmonger, and perhaps now the murderer of Dr David Kelly. But it has made me feel better. And I suppose that is what really counts.