She has fed her family for years while keeping the grocery budget low and has decided to spell it out for all Australians in a new book, so others can follow her lead.

Detailed meal plans, buying in bulk and cooking from scratch are just the beginning of a carefully mapped plan contained in the new title called Eat Well, Save More.

Last week the Sunday Canberra Times, decided to put the theory to the test, by challenging two Canberra families to abandon their normal shopping habits and follow the instructions for a full week and report on their progress.

The results were impressive, the two families - which both had a budget of $100 because they each had five people to feed - managed to stay roughly on target.

However, neither was optimistic about their chances of staying on the plan in the long term.

''I call it an 'in the perfect world book','' mother-of-three Dinah Bryant, of Amaroo, said.

''She recommends shopping without taking your children with you, but I can't always do that.

''The book says to make all of the kids' treats and their snacks for school from scratch but I don't always have time to do that.

''I think some of the recommendations are good and can reduce your bill and some things I will keep doing.''

Mother of three Kirsten Maloney, of Holt, said her family was co-operative but her husband drew the line at taking Vegemite sandwiches to work.

''The book recommends taking the same lunches to work each week, like every Tuesday take a cheese and Vegemite sandwiches for lunch,'' she said.

''I think my husband would rather die. He said 'no'. But a lot of the other things worked for us, I think we saved about $50 from our usual weekly shop. I had already done a lot of things to save money but this got the costs down further.''