MANY people hope to beat the post-Christmas bulge and lose weight this year.

And a new book by Exeter personal trainer Simon Lovell, 29, is designed to help them do just that.

He devised The Lunch Box Diet while working at Fitness First in Tudor Street, Exeter.

Simon, from Alphington, chatted to fans and signed copies of the book at its official launch at Fitness First yesterday.

Published on Monday, January 5, the book has already received widespread media attention, featured in Amazon's top 100 books, and has had to be reprinted due to its success.

"It has featured in the Wall Street Journal, so it is getting some major coverage," said Simon.

"It's a really nice feeling to know something I have done can help people lose weight."

The diet was created by accident in 2007.

Simon needed to eat in the gym between clients. So he put different vegetables in a lunch box and grazed throughout the day.

The diet involves people picking from three food groups: vegetables, proteins and fats such as seeds and dressings.

The food is picked from the lunch box throughout the day, so people are "grazing and not gorging".

Diet followers eat a normal breakfast and evening meal.

Simon shared it with clients, who reported that not only were they losing weight but their hair and skin felt better and they had more energy.

He also put it on the internet, where it was discovered by national magazines and newspapers.

Publisher HarperCollins then came forward and offered Simon a deal — the precise value of which has not been revealed — for two books.

The Lunch Box Diet is an expanded version of his 10-page e-book and includes a 28-day plan and recipes.

The second book will probably be a recipe book. "I have got clients who have been on the diet for two years," said Simon. "It's a diet, but it's more of a way of life for people. It works because it balances your blood sugar and you are less likely to snack.

"It's in a lunch box, so people can have it in the office, have it in their car and are less likely to make uninformed choices."

He hopes the book will have a wide appeal.

"I have made it fun. It's colourful and written with passion and from experience," he said.

"I know it will change the way people think about food so they are able to maintain a healthy weight once they have dropped down to it. It's just so easy."