In the 64-page book entitled 'Get Healthy with Heather', the 40-year-old ex-wife of former Beatle Sir Paul McCartney dispenses advice on how to live a stress-free life, including swapping to a vegan diet.

Heather said: "Spring is in the air and this is a time for change, regeneration and new beginnings. We all know sometimes that life's problems can be quite overwhelming so it's really important we learn to relax properly and iron out those everyday stresses and strains."

Packed with motivational quotes and tips from Heather, the book advises on the best way to move to a vegan diet. The tome is not the first time Heather has extolled the virtues of veganism.

Last November, she launched a campaign with vegetarian group Viva - which is also involved with her new book - encouraging people to drink rats' and dogs' milk to help save the planet.

Arguing that livestock creates more carbon emissions than transport, Heather suggested drinking the different milk could help cut global warming. She said: "There are many other kinds of milk available. Why don't we try drinking rats' milk and dogs' milk?"