In her quest to banish the bulge, Sarah Vine discovers that having her own 'fat policeman' might not be such a bad thing after all

Any products in this article have been selected editorially however if you buy something we mention, we may earn commission

I have discovered the secret to successful weight loss. My dad.

After a week in Italy with my family, eating out in restaurants once, sometimes twice a day, I have returned home quite a bit lighter. And the reason is simple. My dear old dad.

‘Your diet’s not going very well, is it?’ was his opening salvo, before asking me what my BMI was.

I used to get very upset when he said these things to me. Now that I’m a grown up, they’re water off a duck’s back. Besides, having him around is the human equivalent of the inspirational Elle Macpherson picture on the fridge, or those bands that you keep around your waist to stop you overeating: he keeps my diet on track.

Every time I reached for a grissino, I could feel his disapproval. My father is one of those people who can make his disapproval felt without uttering a single sound. It’s a talent he shares with his late mother. Just a simple twitch of the eyebrow is the equivalent of a sharp rap across the knuckles with a ruler.

I imagine Karl ‘No one wants to see curvy women on the runway’ Lagerfeld has a similar effect on supermodels.. What is it he said about Adele? ‘She is a little too fat but she has a lovely face and a divine voice’. Last year, he got into trouble for telling a French TV channel that "the hole in social security, it's also [due to] all the diseases caught by people who are too fat”.

My dad and Karl Lagerfeld: not two men I would naturally place in the same sack. But when it comes to weight, they’re both equally uncompromising, outspoken - and judgemental.

This got me wondering. Is the reason so many people are overweight these days the fact that the views of people like my father (and Mr Lagerfeld) are not considered acceptable? Is society’s desire to spare the feelings of fat people the reason they carry on getting fatter and fatter?

I’m not advocating fat-shaming: that’s just cruel. But the problem with the weight debate is that it’s so politically and culturally sensitive. As a society, we lie to spare our own feelings.

Fact is, my dad is right: I am fat. I know this, of course, and I am trying to do something about it. But one of my problems is that I eat without thinking. Having him around peering over my shoulder the whole time was yes, extremely annoying; but also very useful. For a week I had my own personal fat policeman.

How this can be translated to the general public at large I don’t know. What I do know is that separating weight from emotion is a key step to reducing obesity. After all, no one gets upset about smokers being told that smoking is bad for them; why should it be any different for being overweight? Eating too much is just as damaging in the long run as smoking.

Perhaps the solution is for every overweight person to have a ‘fat buddy’, someone whose job it is to keep them in check. Meanwhile, my dad is coming to stay next week. Better watch those calories!