A man goes to see his Doctor. ‘Doctor,’ he says, ‘I have given up sex and masturbation, high cholesterol foods, bad fats, alcohol and cigarettes. I eat smaller quantities and I go to the gym twice a day, every day. Will I live longer?’ ‘No, you won’t live longer’ says the Doctor, ‘It will only seem like it.’

I was thinking about this story while I read a BBC article last week.

As part of its public service role, the BBC has set out to remind the British population that we are a fat. We are growing, and we are growing too fast. We are grown-ups who have grown too much. As a nation, we are gross and enormous.

I thought that fat shaming was inappropriate behaviour, but the BBC haven’t listened. They have been full on and to prove their words they have written a little online app, so anyone can measure where they are on the overweight scale.

Green results are for those in the right weight band, Orange for the overweight and Red for the obese. I know I could do to lose a pound or two and was ready for Orange, hopefully with a Green tint at the edges.

I input my height, age and current weight into the app and it was at that point I learnt that the BBC isn’t just into humiliating the population they can be very personal.

Just Orange, and nearly Red the BBC said. You are close to being medically obese. I shouted back at the app that my clothes still fit, and the mid-fifties double chin has gone but the BBC stood firm, no doubt showing off a strong 6-pack. They didn’t listen, and the colours wouldn’t change.

I am overweight, but I am not obese. ‘Big boned’, my mother said. ‘Muscle weighs more,’ a friend said, but there was really no excuse. I need to lose some weight.

BMI is the best the medical profession has for large-scale, rule of thumb measurement of over-weight. It doesn’t work for top class athletes, such as rugby players or weightlifters who have very low body fat and a lot of muscle, but it works for 99% of the population, and that includes me. I wasn’t prepared for my results.

To get into the ‘Green’ category I had to lose 15 kg. or just under 16% of my body weight. I prefer the percentage rather than the absolute as it seems far more achievable.

With the Mighty Bertie now 16 months old, my list of reasons to live for a long time is literally growing every day. I am also determined that Sasha and I have a long and healthy life together. It all means that I must do something.

My problem is that much of what a doctor would want me to abstain from has already gone. I drink alcohol very rarely. I had a couple of glasses of champagne with Ben and Hannah at their wedding and with Sasha when I was last in Kiev. But that is it for this year.

With FODMAP, no gluten and voluntary vegetarianism my food is already restricted. I suppose the peanuts could go but there is little else.

The only thing I can give up that will help me lose weight is smoking. It’s not a very complicated argument. The less I smoke the better I will feel in the gym which means I will run further, burn more calories, and lose more weight. It should be a virtuous circle.  Running will become easier, the expended calorie count will rise and the weight will fall.

The best way to make a commitment is to make that commitment public. Don’t hide and whisper it. Shout it out and then at best you get support from friends and at worst, abuse as you fail. So here I go.

This is Smoke-Free May. I am going to give up smoking.

I live in the hope I will lose weight. 0.1 kg is only 3.5274 oz. That doesn’t seem very much. I weighed it out in dry lentil beans. It is nothing.

I know that if I concentrate very hard and my running is committed I can shed 3.5274 oz every day. And that means in the month of May I can lose 3.1 kg or nearly 7llbs or half a stone. I am a grown-up who is determined not to grow anymore.

I will go to the gym and run and run the best I can and see if it gets easier. And when I run I can waste away the time doing the arithmetic of losing different average amounts each day in May. There is no end of amusement ahead of me or as the doctor said ‘No, you won’t live longer. It will only seem like it.’