GUANGZHOU - Kang Shaozhe took out her plastic lunch box after 12 o'clock on Thursday. The young white-collar worker then had her lunch in her office after heating it in a microwave oven in the tearoom.

In addition to rice, Kang's lunch box included fish, an egg, water spinach and cucumber.

"The lunch was cooked by my mother in the morning," Kang told China Daily. "It was delicious, convenient and hygienic."

The 29-year-old, who works in a logistics company in the city's Tianhe district, said she has been bringing lunch from home for about a week.

"Now most of the Chinese fast food restaurants near my office have raised their prices, and bringing food from home for lunch can save money," said Kang, who earns about 8,000 yuan ($1,230) a month.

"I used to spend about 15 yuan for lunch, but now I have to spend more than 20 yuan at a fast food restaurant near my office," she said.

"Now many colleagues who used to eat out at noon have joined me in bringing lunch to reduce daily expenses," added Kang.

Liu Zhaoxiong, another white-collar worker, said he could hardly find a fast food restaurant in Guangzhou where he could pay less than 10 yuan for lunch.

"Now I have to spend more than 500 yuan a month to visit fast food restaurants for lunch alone, up at least 15 percent from previous months," he told China Daily.

"Many women colleagues have begun to bring food from home for lunch, but men usually find it difficult to do that," he said. He added he sometimes had no choice but to buy bread and cakes for lunch.

According to the Guangzhou Association of Catering Industry, most of the Chinese fast food restaurants, including Kungfu Catering Management, and Ducheng and Huangpeng Roast Goose, in this Guangdong provincial capital, have secretly raised their prices by 10 to 20 percent in recent weeks.

Some Chinese fast food restaurants even raised their prices twice in June alone.

Many small restaurants, which mainly sell porridges, noodles, dumplings, buns and other local snacks, have also raised their prices recently.

An official from the catering association expressed concern that the price rises at Chinese fast food restaurants would affect their business and force some diners to visit McDonald's, KFC and other Western-style fast food restaurants.

"Chinese fast food restaurant bosses should improve their management to reduce costs, instead of transferring their rising costs to diners," said the official who declined to be named.

But a Chinese fast food manager in the city's Yuexiu district said many restaurants had to increase their prices amid a surge in the cost of raw ingredients, employees' wages and shop rents in Guangzhou.

There has been a big increase in the cost of meat in recent months and the trend is continuing, said the manager who wanted to remain anonymous.

"And the prices for rice, vegetables and edible oil have also increased by at least 10 percent in recent months," said the manager.

The production cost for a set lunch, including two types of meat, two vegetables and a cup of soup, has increased to more than 15 yuan, while the restaurant has to sell the set lunch for 20 yuan to cover the cost of operating the restaurant, he said.

Meanwhile restaurants have to further raise workers' wages to attract employees. A worker's monthly salary has grown to about 3,000 yuan, up at least 10 percent from the previous year.

Rents for restaurants have also grown from 5 to 10 percent since the beginning of the year, the manager said.