Calvin Harris thinks Sam Smith should write a weight-loss book.
The 'Stay With Me' hitmaker has lost an incredible 50lb weight loss over the last several months and DJ Calvin is so impressed that he has encouraged Sam to share his secret to diet success.
He tweeted: "Sam smith weight loss is legendary he should write a book big up Sam smith @samsmithworld (sic)."
However, Sam recently revealed the secret to his dramatic weight loss is a diet devised by Prince Charles' ex-assistant Amelia Freer.
And although he has lost a dramatic amount of weight, Sam admitted it has not always been easy.
He said: "It's really difficult. The other night I ordered room service and there was so much food.
"I thought there was going to be this magic remedy where you lose weight and be skinny forever. But you have to work.
"It's a struggle every day and there are McDonald's everywhere. Every time I see one I want to munch down on a McMuffin."
And Sam, who piled on the pounds while promoting his smash hit debut album, 'In the Lonely Hour', admitted slurs about his weight used to get him down.
He previously said: "I went to bed last night dreaming of tuna melts. I love food. My relationship with food has just completely changed.
"During the process of this album, I just was getting bigger and bigger and bigger.
"When someone calls you gay, there's not much you can do about that because I am. Whereas, if someone calls you fat, there is something you can do about that."