In the face of a spate of restaurant closures, he's urging his peers to ''forget about competition; we need to look after each other''.

To that end, he has signed up to the Appetite for Sydney, a Herald campaign to support restaurants that has seen more than 50 sign up to offer special diners' deals (details at smh.com.au/appetite).

Venues taking part include Glebe Point Diner; Oliveto Ristorante and Bar, Rhodes; Morena, Surry Hills and Sake Restaurant and Bar, The Rocks.

Deals include Greek yum cha for $30 at Xanthi, city; a $35 main course and drink lunch deal at Aria and a main course and drink for $20 at Sailor's Thai, ivy.

As the fallout from restaurant closures continues, the spotlight is turning to why. Experience beyond the kitchen is a factor.

Peter Lew is the modern face of the restaurant business. He's a chartered accountant, with a law degree who worked at Macquarie Bank and was chief financial officer at fashion company Sass & Bide before he and partner Nicole Galloway opened Cantonese diner Fei Jai in Potts Point.

It's a far cry from Matt Kemp's experience. He learnt to cook, but not much else, when he became a chef 25 years ago. His business Montpellier Public House is part of the spate of restaurant closures.

University lecturer Stephen Shaul identified the biggest pitfall of many failed restaurateurs.

''They don't take account of all the expenses … they may have done a profit and loss projection but haven't arranged to be paid themselves,'' he said.