Sam Smith admits it's a ''struggle every day'' to stay slim.

The 'Stay With Me' hitmaker has shown off his dramatic 50lb weight loss over the last several months after going on a diet devised by Prince Charles' ex-assistant Amelia Freer, but keeping to healthy habits isn't always easy.

Sam told The Sun newspaper: ''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 for ever. 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.''

The 23-year-old star piled on the pounds while promoting his smash hit debut album, 'In the Lonely Hour', and even recently dreamed of gorging on a tuna melt toasted sandwich.

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.''