Singer Sam Smith lost 14 pounds in 14 days and now everyone is going nuts for his new diet

In February, "Stay With Me" singer Sam Smith took home four top awards at the Grammys.

Since then, the 22-year-old London-native has been increasingly focused on his health, posting his workouts and healthy meals to his 3.2 million Instagram followers.

Today, he is noticably thinner.

And apparently it's all thanks to British nutritional therapist Amelia Freer.

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

Since Smith posted his secret weight loss weapon last week, Freer's U.K. diet book has been in such high demand that publisher HarperCollins International "sent its U.S. division scrambling to get the book on shelves," reports The Wrap.

"Until Smith's post racked up nearly 150,000 likes on the photo sharing app, HarperCollins had no plans to publish the book stateside. But within three days acquired the U.S. rights and rushed the book into print," a spokesperson for the publishing house confirmed to TheWrap.

After Smith's plug, Freer quickly gained her own Instagram following:

"I am beyond thrilled to learn that my book is number one on Amazon and iBooks in the UK - and also hit the top spot on Amazon in the US. Wow! I am having to pinch myself. It was a dream come true for me to just write a book but for it to be so well received is utterly humbling. Above all, it's awesome that Nutritional Therapy is getting the attention it deserves and that Eat Nourish Glow is impacting so many peoples lives and spreading health! This is beyond anything I could ever have wished for. x"

Freer's approach in "Eat Nourish Glow" encourages, clean home-cooking.

"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 told ABC News last week.

And judging by Smith's recent Instagram photos, he seems to be following Freer's rules.

"Hot water for lunch for me!! Thanks @ameliafreer !!!! Love you really x #fastingishorrific"

"Now that is a seriously healthy dinner"

 

"These are saving my life right now during this 12 day detox with @ameliafreer xx"

 

"Tonight's dinner. Steak x @ameliafreer is changing my life x"

"Temptation."

 

"Aubergine BaBa and Mozzarella Salad for dinner x"

 

"Look mum no hands truly do the best custard tarts!! Old street, London!! Don't worry @ameliafreer , It's not me eating it x"

 

"Gym is kicking my ass today."

 

"Eating Clean @ameliafreer x"

 

"Beautiful lunch x"

 

Looks like Smith's hard work is paying off.