The suit I recognised immediately. It was the one my husband wore on our wedding day, 33 years ago. The look on his face as he slipped on the jacket was pure glee.

The buttons fastened with ease. The seams and zips were loose and unstrained. He made a triumphant twirl and asked me: "So what do you think?"

"I wish you'd put some weight on," was my honest reply.

It wasn't that I was jealous - OK, maybe I was, just a tiny bit - but Joe's diet has been going on for more than six months. He has lost an incredible 22 kilograms, bringing him down to his target weight of 85 kilograms. His waist is a youthful, trim 86 centimetres, instead of a portly, belt-popping 101 centimetres.

Advertisement

Note the ease with which I rattle off those statistics. Heaven knows, they've been quoted at me often enough.

For the fact is that Joe, 58, who's a university lecturer, hasn't just lost weight in the past six months, he's lost an awful lot of what made him him.

That lovely, carefree, chunky bear of a man, whom I adored snuggling next to on the sofa, with a takeaway pizza and bottle of white wine, has been replaced by a slightly sanctimonious, calorie-counting bore, who looks as if he could be carried away by a breath of wind.

As a couple, Joe and I were once perfectly matched. He is over 6 ft and I am 5 ft 10, so together we stood as life's bookends. Tall, sturdy and stocky, we were a formidable, united front.

Slim on our wedding day in 1982, our weight crept up together, like the soulmates we were. I blamed contentment for my increasing size - and having four babies in three years. I tried various diets, but never managed to keep the weight off.

By the time the children hit their 20s and left home, I was a size 18 to 20 and had abandoned all pretence: I was fat because I enjoyed eating chocolate and sitting down more than abstinence and jogging, so I pretty much gave up.

It's not as if my weight bothered Joe. His waistline was expanding at the same rate. He was a demon for snacking on crisps, nuts and biscuits and that, coupled with little time to exercise when the children were young and at home, meant he, too, grew larger year on year.

The flab stayed resolutely stuck as he crept into middle age. By the time he hit 50, he was just over 107 kilograms.

Yet we were happy, so happy, in fact, we didn't even own any weighing scales, other than the kitchen ones I used for cake ingredients.

Scales were absent from our house partly because we were in denial about our weight gain and partly because I didn't want my children - three girls and a boy - to be affected by the mania about weight and body image.

Yet last summer, something changed in Joe. We'd holidayed in Ireland for a month: our first empty-nester long break to completely relax. We slept late, read a lot, cooked some delicious meals and baked some spectacularly tasty cakes and biscuits.

The upshot of our great Irish escape was that Joe gained 4.9 kilograms in four weeks. "I must have put on weight every day!" he cried in horror, returning from a doctor's check-up, when his full size was revealed for the first time. "This is an emergency. I'm shifting this fat!"

Of course, I only half-believed him. Like me, he'd made half-hearted attempts at losing weight in the past, with very little effect. When I questioned him on what sort of diet he was planning - I do all the food shopping and cooking in our household, and I wanted to know what to buy - he got terribly defensive, and it started a row. He seemed to think I was being patronising and that I was implying he didn't know what he was doing.

"There's only one way to lose weight and that's to eat less and move more," he declared.

So there it was. Mr Macho declared war on his poundage and was going to shift it using only willpower and self-denial.

To my amazement, he did precisely that. I cannot deny he was impressive. Joe cut out all snacks between meals and left the car keys at home and cycled everywhere. Plus he doubled the daily distance he walked our dog, Banna, meaning that he, too, lost two kilograms on his master's diet and exercise programme.

Joe resolved to lose the weight all by himself; no mentor, clubs or medical support. And without me, too. He almost led a separate life.

Our social life took a serious knock. If I suggested a takeaway pizza, a curry with friends or a glass of wine, he would wag a finger and tut, as if I had suggested something illegal. Frequently, I'd go out on my own or not bother. Friends grew used to my excuses: "Joe's on this diet you see . . ." I said, pitifully.

The saddest thing was that we no longer ate together. For 30-plus years we'd sat, side by side, for meals, the most convivial and bonding checking-in points of our day.

Yet on day one of the diet, I found my services at breakfast were no longer required. Joe nibbled nuts and natural yogurt, instead of my speciality: porridge with a glorious puddle of honey.

Elevenses - another favourite time of our day, when we'd meet in the kitchen at weekends for a sticky bun and a coffee - vanished. I sat, miserably glowering into my cappuccino as Joe lectured me on what he considered a "medium" banana. The supermarket ones I'd bought were too calorific for him, he hectored, and could contain up to 150 calories.

I held his gaze for a moment, expecting him to realise how ridiculous he sounded. For him to burst out laughing and for the two of us to collapse in helpless giggles, but his face remained stony. I began to worry he was losing his sense of humour along with his belly.

There were times when Joe's diet regime made me feel lonely. As a writer in London, I work from home and looked forward to his homecoming for a catch-up on the day over tea and biccies. Later, we'd chat and share a glass of wine as I cooked dinner.

No more. Joe decreed he had to eat early to maximise his weight loss. This meant that his dinner was served sometimes as early as 5.30pm. That's a time of day I consider more suitable for a nursery tea. Often, I'd leave him to it and eat alone later.

Pre-diet, we'd often eat together in front of the TV. I loved this cosy time together, but that joined the contraband list, too.

Joe's new food rules include "mindfulness" eating, whereby he concentrates on every bite. This means he always dines alone at the kitchen table, with no distractions allowed such as the radio or a newspaper. Or me talking.

Joe being slim has made me a fitness widow. He is now a born-again athlete who cycles 65 kilometres on a Sunday morning and walks everywhere just for the joy of being able to.

Recently, we went on a long walk, about 16 kilometres, and that day I realised how fit he's become. I spent the last three miles of our walk trailing behind him, numb-legged and short of breath on the climbs.

He strode off and I got a good rear view of my new-shape husband. He looks great and for the first time in 33 years, I felt a pang of insecurity. Now 57, was I going to lose my trim husband to a slimmer, fitter woman? Was I going to have to lose weight, too?

I returned home thoroughly miserable. I just wish we could uncork a bottle of wine and open a packet of biscuits - and I could have my husband back.

Joe's story

I'm not in the least body conscious. I only look in the mirror to shave. So me deciding to lose weight was nothing to do with vanity.

It was everything to do with how I was feeling: heavy and slow, and the fact my clothes were too tight. And being heavier made walking and cycling, which I enjoy, harder.

On holiday I gained nearly five kilograms and I came home looking as if I was pregnant. That shocked me and I was worried that something had gone wrong with my metabolism.

But there's no real mystery: I was eating more than I needed.

When I told Anna May I was going to diet I think she was irritated because she thought I was implying she should lose weight, too, which I wasn't.

She suggested some faddy eating plans that sounded stupid to me and mentioned that maybe I should join a club.

Why would I do that? It's my weight, my mouth, my paunch - and my problem.
When she saw I was serious, Anna May was supportive. She changed what she cooked - fewer carbs and more protein - and switched mealtimes so I could eat earlier.

But whenever I mentioned weight, she'd get touchy and assume I was criticising her. In the end, it was easier to concentrate on slimming and not talk about it.

My approach was to eat less and move more, so I suppose I did develop some anti-social habits, such as never eating between meals and having dinner early and preferably alone so I could concentrate on the food. I never realised how much this upset Anna May.

She says she likes me heavier, but I think she just prefers our life before. I enjoy being slimmer and Anna May should respect that.

We've been together for nearly 40 years and I love her fat, thin or whatever size she chooses to be.

I'm not going to sacrifice a good marriage just because I can fit into 34 in waist trousers. Anna May knows me better than that.

- Daily Mail