How do I let my obese friend know that I don't fancy him?

'If we were sexually attracted to every nice person we met, there wouldn’t be time for all the sex': Mariella Frostrup. Above: a silhouette from the 1830s. Photograph: EPA

The dilemma I've been getting close to a lovely man. We've been spending time together and really enjoy each other's company. He is an incredibly loyal, gentle and loving person. We are on the same wavelength on many subjects and talk together for hours. I could almost say he is my perfect man – if not for one thing. He is very overweight, in fact obese. I am slender, and have never been with anyone who was overweight or found them attractive. I had vaguely thought that this would cease to be an issue if I had strong feelings for him. However, things are coming to a head now and I find I still don't want to be physical with him. I feel bad about this. How on earth can I let him down gently, given that he is one of the best people I've ever met?

Mariella replies First things first: you've no reason to feel guilty. If we were physically attracted to every nice person we met, there just wouldn't be enough time for all the sex. Indeed if "nice" were a qualification for a romance, potential partners would be far more prevalent altogether. Unfortunately, such is the pernicious nature of the human psyche that for many of us, qualities such as "loyal, gentle and loving" are more appealing in a dog than a human.

Positive qualities like the ones you outline fail to endorse our insecurity and self-loathing, and so we often stare right through the people who display kindness, looking for someone who has a keen eye, not for who we are but for what we lack.

The love interest who recognises our shortcomings by ignoring our charms, breaking promises or treating us unkindly is all too often the one we set our hearts on. In love we make excuses for unacceptable behaviour. I've had letters from people whose lovers are only steps away from criminality in terms of abusive behaviour and yet the advice their victims tend to seek is how to cling on to or change these beasts of both sexes, rather than escape them.

Our most common behavioural pattern appears to be that if you treat us well, we'll be off in a far more dysfunctional direction as fast as our disappointingly short, broad, scrawny (delete as appropriate) legs can carry us. You have done well by embracing this man's positive virtues so far, but now instead of taking pride in a?friendship you are beating yourself up about not finding him attractive.

I appreciate that this is partly down to your desire not to unnecessarily hurt this man, but you are adding psychological complications to what is essentially a simple biological matter. You don't fancy him. It's far more acceptable to say you won't get involved with someone because they smoke, take drugs, drink excessively, are a depressive, a cat lover or even a?Mormon than because they're fat. Obesity is the condition that dare not speak its name, and even writing the word "fat" makes me uncomfortable. Obviously that's not the term you'd use, or the reason you'd give for not wanting to take things further on the physical front.

It's important to recognise that your heightened sensitivities are making you dwell on this far more than you would if this was just some averagely proportioned bloke you didn't find sexually alluring. Whatever your reasons, you don't want to have sex, and that is your prerogative. Forcing a platonic relationship to become physical is rarely successful. If you like this guy enough to maintain the friendship, then your companionship may yet help to improve his sense of worth and that in turn could inspire him to tackle his weight issues. You certainly can't do it for him.

It's not unusual for a potential mate to lose lustre closer up and reveal copious or insurmountable emotional baggage. Whether it's a secret wife or an eating disorder, mental health issues, a mountain of debt or an addiction, other people's issues can make them unsuitable partners. Lionel Shriver's recently published Big Brother, a compelling fictionalised account of her battle to "cure" her now deceased brother's obesity, is worth a glance. The novel offers a salutary lesson in why you have every reason to fear moving forward, and not just on a sexual level. Obesity is an outward symptom of an even bigger internal struggle, and it's volatile, emotional terrain to go wandering into unwittingly.

I'd gently make clear to your companion that your intentions toward him are friendly rather than romantic, a choice you have no need to explain. Make sure he appreciates how much you treasure his company, and who knows, your proximity and friendship might eventually give him the strength to face his demons. Attempting to address his obesity is this "lovely" man's challenge, and it's your support, rather than your guilt, that will help him on his way.

If you have a dilemma, send a brief email to mariella.frostrup@observer.co.uk. To have your say on this week's column, go to guardian.co.uk/dearmariella. Follow Mariella on Twitter @mariellaf1

View the original article here