Shania Twain thinks "happiness" is the key to good health.

The 59-year-old country music star is a keen advocate of following a healthy diet and exercise regime and just "enjoys" it all but admitted that inner feelings truly have "everything" to do with how she looks on the outside.

She told Fox News Digital: "There is no secret. I take that as a great compliment, I just enjoy good health and I think happiness has everything to do with it."

The 'That Don't Impress Me Much' hitmaker recently came to the conclusion that she "can't change" her body and wants to be satisfied with it rather than feel the need to cover it up as she admitted to walking round naked in her own home so she could embrace herself.

She told The Sun newspaper's Bizarre column: “I decided that wherever there was a mirror and I was naked in my house or hotel, that I would keep the lights on and I would look in the mirror.

“A lot of people as they start ageing — and even young people — they don’t want to look at themselves in the mirror naked, and I think that is such a shame.

“Every month or day that I may notice another sag or another bit of cellulite, I want to know it’s there.

“I want to be OK with it instead of thinking, I have to cover it up or not to look.

“I can’t change it and I don’t plan on changing it superficially."

In terms of diet, the 'You're Still The One' songstress admitted during her gruelling schedule for her 'Come On Over' residency in Las Vegas that she can only drink fluids during the day because she needs to be able to "pace" herself ons tage.

She said: "I am an athlete, I have to breathe, I have to project. I have to pace everything. I only drink fluids all day until after the show.

"I drink my food, so I blend my food. Lots of blended ­spinach and blueberries."