Brits 2015
Singer Sam Smith has lost 14lbs (one stone) in just two weeks thanks to a nutritional bookAFP / Getty Images

Stay With Me singer Sam Smith has left some fans concerned by his quick weight loss, with those worried about his shrinking figure urging him to not get any thinner after losing one stone in a fortnight.

The 22-year-old shared a photo of himself on Instagram while at the NRJ Music Tour in Lille, France, wearing a long, fitted camel coat that highlighted his dramatic weight loss.

Although many applauded Smith for shifting the pounds, there were some who feared he could be taking it too far. One Twitter user, @DiLodge8, warned: "You are a lovely boy - don't get any thinner though !!!" while another, @sourthug, wrote: "I liked the chubbier Sam Smith better."

According to The Mirror, another Instagram user said: "Love you Sam but please don't lose any more weight." The commentary has also continued on Twitter, with many others expressing their concerns:

In March, the Lay Me Down hitmaker unveiled his sudden weight loss in an Instagram post, posing with nutrition book, Eat. Nourish. Glow. written by therapist Amelia Freer.

Without revealing exact details of his new diet, the Grammy-winner credited Freer for "completely [changing his] life".

Speaking with ABC News after the singer's big reveal, Freer explained her approach to helping clients adopt a healthier lifestyle.

"So for me the key is about it being real, getting back in the kitchen, cooking from scratch, making sure they are not relying on junk processed convenience food," she explained.

However, the news outlet's medical contributor Dr. Jennifer Ashton, questioned how safe it was for Smith to lose such a large amount of weight in a short space of time.

"Fourteen pounds in two weeks is not alarming unless a person losing that weight has any pre-existing medical problems. When you talk about eating properly, people who do have weight to lose will see dramatic results," Ashton said.

The British singer is currently in the midst of a UK tour and recently performed a sold-out show at London's O2 Academy Brixton.

Beautiful day in Lille. Now en route to Paris!! I'm excited to see you x

A photo posted by Sam Smith (@samsmithworld) on