I don't think there is one unfortunately... I think you can print out your food diaries after filling them on lifeline online but I don't know if you can print blank ones to fill in yourself. How about starting a diary here on the forum in the food diary section? Its great and a huge amount of people share their food diaries there so you can see what everyone else is eating for ideas etc.
If you'd rather have a paper diary to fill, I have a few spare ones so if you send me a private message with your email address, I can scan and email you a copy and you can then print off as many as you want!