One Direction's Louis Tomlinson has come under fire for promoting a weight-loss website on Twitter, in a tweet which could have been seen by 13.9 million of his followers.

Louis left many surprised when he advertised health supplement company Bootea - famed for their appetite-suppressing products - on Twitter yesterday.

"Had an amazing @BooteaUK smoothie from Bootea.com this morning #booteashake"

The post was seen by millions of his young fans, with 14,000 of them picking it as a favourite and 10,079 retweeting the message before it was promptly deleted.

And, with the number of eating disorders in the UK increasing by 24% in the last ten years, the singer's actions are particularly irresponsible, particularly as he is so admired by young and impressionable fans.

Speaking to the Mirror, Lucy Russell – the director of campaigns for charity YoungMinds – slammed Louis' behaviour as "irresponsible":

"It’s really irresponsible and short-sighted of him. Louis has such a huge audience – especially young girls. It’s very silly and remiss of him and the people around him."

"Three children in every classroom have a diagnosable mental health problem. Louis is a mentor to millions. The ones who are vulnerable are easily led and will be thinking: ‘I’ll buy some of that.'"

Louis has suffered a huge backlash on Twitter, with many users calling him out on his actions. However, since then, the 1D boy's spokesperson has insisted that the 21-year-old had no idea he was endorsing a weight-loss product at the time.

"Louis tweeted about the drink as he had one and enjoyed it. However, he did not realise they are associated with weight-loss and would never endorse weight-loss products."

Do you agree that Louis Tomlinson was irresponsible to tweet about a weight-loss product? Should celebrities be made more aware of how much of an impact their tweets can have on young fans? Comment below for your chance to win a £25 supermarket voucher