This week, a cabinet minister's son, whose aim is to become a top bodybuilder, threw the sport into the news. John Fisher, a coach and former Mr Universe contender, and one of the young people he trains, 19-year-old Simon Gilchrist, talk muscles. But first, asks Emine Saner, is bodybuilding getting more popular among young people? And if so, why?

John Fisher: I think it has got bigger in the last five years. A lot of pop groups and actors work out, and that is an influence. It's the look for men now. For a while, the look for guys was to be really skinny. It's different now.

Simon Gilchrist: I think music artists and videos have had an effect. I don't know what other people my age think – they probably just want a bit of muscle. I'm a bit different because I want to get really big. I think you inspired me in that. About two years ago, I came to the gym with one of my friends who was into it. He gave it up, but I loved it.

JF: That's the same way I got into it. I saw a friend who I hadn't seen for a while and he came knocking on the door. It was the summer and he had a tank-top on and looked good. I went to the gym with him and I carried on. It gets you. And no matter how big you get, you're never big enough.

Emine Saner: What is the ideal?

JF: If you look at Mr Olympia, the top professional bodybuilding show, those guys are competing at around 19 stone with 4% body fat, which is unbelievable.

SG: I'd like to get to about 18 or 19 stone. That will take about 10 years of training.

ES: Why do you want to look like that?

SG: Just seeing the other guys. I look at them and want to look like that.

JF: I think it's in the genes, it's just in you. With me, it was a fascination with muscle and what you can do to your body. On top of that, there is a lot more pressure on the way men look now.

SG: Even if you do look good, you can still feel self-conscious, but it's not just about the way you look, it's the way it makes you feel. There's nothing better than really aching after training. I train for about an hour and a half, six days a week. It's a good feeling, knowing you're going to grow.

ES: Do you want to go professional?

SG: That's the dream, yes. There are a lot of sacrifices, but I would be happy to do that. When will I be ready? Five years? I'll train, build up muscle, and then start dieting and losing fat. If I sorted my diet out seriously I could do it in a lot less time.

JF: You could definitely do it in two or three years. I stopped competing when I was 23, which is young, because a lot of men are competing in their 40s. I gave up because of the drugs thing – for me to go beyond where I had got to, I'd have had to get heavily into the drugs side, and I called it a day. I don't know if I'd be here now if I'd carried on with it [steroid abuse can lead to organ failure and severe mental problems, among other side-effects]. Part of the reason they won't let it into the Olympics is because of the drugs problem. A lot of young people do take steroids, but I think it tends to be for short periods. But steroids will always be there and it's bigger now than it's ever been, because they're easy to get.

SG: There are people who don't know anything about steroids, who just buy them and take them. They think they can just take them and get big. They don't realise how hard they still have to train. But yes, there is a pressure on young bodybuilders to take them.

JF: I've never had anyone come up to me to ask for steroids, and I have never [supplied], nor would I supply, them. There are natural shows which have been around for a few years for people who want to stay clean and natural. But if you're in a show that isn't natural, then if you're [not on steroids] you're going to look silly up there.

SG: I wouldn't use them. Well, maybe after a few more years, and to get really big. Maybe when I'm old and need a boost.

JF: What's really old? When you're, what, 25? [laughs]

SG: I'm unsure at the moment. I'm just enjoying it. Although the training is easy compared to the diet.

JF: Dieting for a show can be gruelling, because you've still got to lift heavy weights, and you need to be taking in the calories. When I'm training, I'll have six eggs and porridge in the morning, then I'll eat things like tuna, brown rice, broccoli, chicken. I've heard some of the top pros have 140 eggs a day. They'll have 20-egg omelettes several times a day. That's extreme.

SG: I find the diet the hardest thing. You get sick of it. I have chicken and rice every day, cottage cheese before I go to bed.

ES: And protein powders?

JF: You normally have the protein powders in between meals, so if you think you're going to miss a meal they do the job.

SG: Or after training, when your body wants to repair tissue, but I prefer eating.

ES: Isn't all this really unhealthy?

JF: If you overeat, you can lay down too much body fat and you can overdo the protein, which is not good for you. In the 70s, I would drink eight pints of milk, that's what people did. It made me lactose-intolerant.

ES: There are people who will see you as, well, I don't want to say freaks, but …

JF: In a way we are freaks. We're not normal, it's a tiny percentage of people who don't just go to gyms but compete in shows as well. That's probably what appeals to a lot of bodybuilders – you stand out. If you're walking down the street, I suppose you want people to think, "Look at the size of him."

SG: Nobody has ever said anything to me about it, but I don't really care what people think.

ES: According to reports this week, the son of the MP Caroline Spelman has said his parents are not supporting his bodybuilding ambitions.

JF: When I started, my mum wasn't happy at all, but I think it was the diet side she didn't like. When I started getting trophies she got more relaxed.

SG: I live with my granddad and he's very encouraging. He doesn't think it's strange. I feel a lot stronger. I feel more confident. That's one of the reasons I started – to build more confidence. I've made lots of friends doing it. It's a good community.