Eloise Parry died on 12 April after taking diet pills she had bought off the internet. Her mother, Fiona Parry has been begging people not to do the same.
Police believe the tablets Eloise bought contained a dangerous industrial chemical. Her mum Fiona says two tablets would have killed her - but she had taken eight, an inquest into her death has been opened and adjourned by a coroner.
Laura Hancock, from Youth for Christ told Premier's News Hour: "Whilst young people don't understand the dangers of these diet pills, it's a much deeper issue - almost that they'll turn to other things... in a quest look the way that they think they should, or they would want to."
She added: "Often a young person can list very quickly all the things they're not good at... the things they don't like about themselves, and they'll often struggle to name one thing they like about themselves.
"I think adolescence is a time where you discover who you are, where you discover what you're about, who you want to be, who you don't want to be - and a lot of marketing speaks into that and has a lot of negative effects.
"These products aren't sold by people telling you that you're fine just as you are - and so I think a young person's vulnerability is really played upon to get their money, and get their vote on these products."
She stressed that parents and friends need to tell young people how much they love them, she said Christians must speak biblical truth to young people and tell them that "they are a masterpiece that they are created and loved just as they are."
Listen to Premier's Antony Bushfield speak to Laura Hancock here: