The 24-year-old singer from London slimmed down considerably after hitting the big time for his stunning vocals.
Many celebrities yo-yo diet, going from chunky to slim and then back again. So how has Sam managed to keep all the weight off?
The hit-maker credits his new super trim figure to nutritional therapist Amelia Freer, whose other celebrity clients include James Corden.
Incredibly the British singer lost 14 in 14 days, wowing fans with his sudden transformation.
In 2012, when Sam hit the big time after featuring on a single for Disclosure, he was notably bigger than his current look.
The star shocked fans at the 2016 Grammy Awards with an incredibly svelte new image and a new haircut.
When probed on his transformation the singer told reporters: “I’ve just not eaten like a pig anymore — that’s what I’m doing, basically.”
In September of that year he revealed that he had lost more than 50 pounds.
“It’s very, very difficult,” he told Entertainment.
Stay With Me singer Sam Smith’s 2017 photos show new physique
“I love food so much, so it’s a constant battle. It’s always going to be a battle, but I’m trying my best.”
While Sam was modest about his weight loss, his huge achievement was down to Amelia Freer – a very A list nutritionist.
Amelia has worked with James Corden, Emma Thomas and Boy George.
Sam posted an emotional message to the nutritionist, posing with her book.
“Three weeks ago I met a woman who has completely changed my life.
“Amelia Freer has helped me lose over a stone in 2 weeks and has completely transformed my relationship with food,” he wrote.
“Everyone go check out her incredible book, and start to live healthy. It’s not even about weight loss it’s about feeling happy in yourself.”
Another singer who has lost an impressive amount of weight is Susan Boyle. Express.co.uk charted her weight loss story.