The Stay With Me hitmaker has been documenting his path to wellness on, sharing photos of himself in the gym and eating healthier foods over the past month.

On Tuesday (17Mar15), he took the opportunity to thank his London-based nutritional therapist Amelia Freer and her best-selling book Eat. Nourish. Grow. for being the driving force behind his new lifestyle.

He wrote on Instagram, "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 and thank you for making me feel so happy inside and out @ameliafreer."

Freer has a number of other celebrity clients including another British singer Boy George.