Most restaurants like customers with big appetites, but waiters at the Tsui Wah restaurant chain have been instructed to advise them not to order too much. The reason? It's the latest chain in Hong Kong to join a global campaign not to waste food. 'We want our customers to enjoy their food and be able to finish everything,' Tsui Wah chairman Lee Yuen-hong said. 'It is actually far more enjoyable to just be 70 to 80 per cent full. And we want this campaign to start from the root, which is changing the mentality of consumers.' Waiters at its 18 branches have been trained in a new campaign launched yesterday to reduce food waste by chefs and customers. The size of portions will be adjusted based on day-to-day measurements of food waste and staff will advise customers on how to order a sufficient amount of food. 'If customers still can't finish their food, we will see it as a problem with our portions and we will rethink our recipe,' Lee said. 'We used to have huge store rooms to keep our foodstuffs, but now we don't need to. We use fresh ingredients and try to keep as few foodstuffs overnight as possible. 'This means we do not have to store large mounts of food that may be tossed out because it's expired.' One of the first steps of the campaign is staff will be using a smaller ladle when scooping rice. Christy Lee Sin-ying, Tsui Wah's corporate planning manager, said: 'We have always had the option for customers to order less rice, but it was just based on our staff's rough estimate of what less rice is. Now we can be consistent.' The campaign, led by Unilever Food Solutions, has so far been launched in the US, the Britain and on the mainland.