The Restaurant Business Association expects more than 200,000 workers to lose their jobs after the government imposed new measures that prohibit dining in at eateries.
New restrictions prevent dine-in services in six provinces -- Bangkok, Chiang Mai, Chon Buri, Nonthaburi, Pathum Thani and Samut Prakan -- effective from May 1.
Ladda Sampawthong, the association's president, said the new restrictions will have a huge impact on medium to large restaurants because all targeted provinces have many such outlets.
"Since the government reduced service hours to closing at 9pm, dine-in customers at restaurants are 65-70% of normal levels. However, with a ban on sit-in dining, I wonder how many will still want to come," Mrs Ladda said.
She said customers are more panicked with the fresh wave of the pandemic compared with previous outbreaks because of the high number of infections.
During the first two waves, customers ordered food via delivery services or take-away, but now some customers have changed their behaviour, said Mrs Ladda.
More people are also opting to cook at home, resulting in fewer restaurant orders.
Some 55,000 restaurants are association members, with about 80% of them providing delivery.
She forecast 200,000 restaurant workers are likely to lose their jobs, both in the short term and long term, because the pandemic requires time to improve.
"This new restriction on restaurants has been enforced too soon. We understand the purpose is to stop the virus spread and are willing to follow it, but our main concern is the employees," said Mrs Ladda.
She said 2% of restaurants across the country have closed permanently because of the previous outbreaks. She predicts the third wave will add another 1-1.5 percentage points to the closure rate.
However, some new owners are entering the restaurant segment despite the pandemic.
In Chiang Mai, representatives of the Chiang Mai Restaurant and Entertainment Venue Association on Friday called on the government to reconsider its order to close dine-in services, saying the ban would seriously affect more than 80,000 workers.
According to Kasikorn Research Center, if the government does not enact a lockdown, the food business in 2021 is valued at 410-415 billion baht. In 2020, the segment generated 405 billion baht, down 6% from 2019.
The centre suggests food operators convert to a smaller operation such as pop-up stores, food trucks or cloud kitchens to access customers.