Visitors to Shanghai Disneyland cannot bring any food to the theme park.
The park's operator said it has updated its rules, which are now consistent with other Disney operations in Asia.
Before, food kept in sealed commercial packing was allowed, while instant noodles and food in containers requiring reheating or home-cooked meals were prohibited.
Water bottles are also being monitored by the theme park. Beverages with volumes larger than 600 milliliters are forbidden, as is alcohol.
"Our park policy around outside food and beverage is consistent with our other destinations in Asia and many theme parks across China's mainland," according to the Shanghai Disney Resort.
Customers, however, have complained on social media that eating in the park is more costly than doing so outside.
The resort's response is that visitors can enjoy their own food and beverages and dine outside the park in a convenient setting in Disneytown or the Wishing Star Park. They can then re-enter the park after their meal.
Shanghai Disney Resort features a variety of dining options that it said suits every taste and budget. The resort's culinary team constantly reviews the menu and incorporates feedback from guests, the resort added.
Shanghai Disneyland said that in recent months it has expanded its selection of affordable food offerings, including fresh fruit and vegetables.
"We regularly review our park rules and from time-to-time make adjustments to meet the needs of our operation," the resort said.