While some fans have expressed concern over Sam's seemingly sudden weight loss, others are encouraging and see him as an inspiration. So, what's his secret? And how has he managed to remain eating his favourite foods while losing weight?
Well it's mainly down to one woman, health blogger Amelia Freer! Here's how she helped him lose over a stone in just two weeks, and five other diet and exercise secrets Sam swears by.
Eat healthily, even on the roadhttps://www.instagram.com/p/6eSRwPR2QJ/
Sam is a big fan of a healthy cookbook called 'Eat. Nourish. Glow', by healthy eating expert Amelia Freer. He's often plugging her recipes and lifestyle advice and seems to have a really close bond with the nutritionist. Even when he's on the road he's keen to show her, and his fans, that he's sticking to sensible food choices. Sam calls his friend's book 'incredible' and often credits her for his weight loss.
He was smitten early on, commenting on Instagram in the first three weeks of his diet change: '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.
'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. Love you Amelia & thank you for making me feel so happy inside and out @ameliafreer #eatnourishglow'
Some of Amelia's top tips are to throw out all the junk food in the house, stop snacking and to stay hydrated.
Fit in regular exercisehttps://www.instagram.com/p/_LG0UGx2S4/
Despite Sam's obviously quite busy schedule he can often be seen exercising on his social media channels. The pop star has a liking for all sorts of workouts from weight lifting to yoga if his Instagram is anything to go by.
This combination of exercise and diet seems to have done wonders with reports of Sam losing 14 pounds since he started his new approach to weight loss.
Have regular detox dayshttps://www.instagram.com/p/zx1H-bR2Xv/
The pop star loves to share his little tips and tricks with his fans and a recent one was this bottle of chilli flakes. Chilli is well known for speeding up the metabolism so it could be that Sam was feeling a big sluggish and needed a pick-me-up. And guess who was behind the idea? Correct, his old pal Amelia.
Cook from scratchhttps://www.instagram.com/p/9eFoqCR2U5/?taken-by=samsmithworld
One of the most important things Amelia stresses in her book, which Sam religiously follows, is to cook from scratch. Sam seems to be taking notes with frequent snaps of his food prep.
Eat the rainbowhttps://www.instagram.com/p/2hHpwqR2cE/
Just look at the colour of that veg! Ditching the carbs seems to be a common theme throughout celeb diet trends and Sam appears to be on board. This boy loves his fruit and veg with pics a-plenty of healthy juices, salads and meals involving the lovely stuff.
It's ok to have 'cheat days'
Luckily for all of our viewing pleasure Sam isn't overly preachy. We love this snap of a full fry up.
The singer has previously publically spoken about his love of food, telling Magic Radio, 'Food is the big thing for me. I'm moving around all the time, but I just love food. I still love it. It's going to be a battle for the rest of my life.'
'I mean it's not like this horrible diet that kills me. When I want to eat something bad I do it, but I've just got to stay on top of it, which is tough. I just love fried chicken and cheese!'
Don't we all Sam, don't we all.