Zizzi's staff have had their perks cut as the National Living Wage puts a strain on the business.
The private-equity owned restaurant chain has become the latest business to respond to changes in the minimum wage.
Waiting staff have had their free meal choices limited while a cap has been imposed on how much they can earn from tips.
Staff will now be offered a margherita pizza or bowl of spaghetti, while they can keep just 50 per cent of credit card tips and the service charge, with the remainder to be split among supervisors and kitchen staff. Previously the split was 70:30, according to the Financial Times.
More than 1.8m workers were given a pay rise on 1 April after a new minimum wage came into force, requiring employers to pay at least £7.20 per hour to staff aged 25 and over. It is expected to rise to £9 an hour by the end of the current parliament.
Last week chancellor George Osborne warned firms not to cut perks due to the National Living Wage, arguing that it would hurt their reputations.
"It's not the spirit of the law. Companies should be much more careful about their reputation," he told ITV.
Tesco and Caffe Nero, along with the John Lewis Partnership, have all reduced some perks.
Caffe Nero said it wouldn't be giving staff a free lunch anymore when they are on shift as part of a "pay review", while John Lewis said it would stop paying higher hourly rates for overtime or work on Sunday.
Tesco, for its part, announced that from 3 July all staff who work on Sundays and bank holidays will be entitled to pay at time-and-a-half, instead of the double rate of pay currently received.
Meanwhile, it was reported earlier this month that nearly 60,000 companies hit by the national living wage were already in "financial distress".