Officials from the Shanghai Consumer Council raided 29 popular eateries and reported those using too much oil or fat or the amount of certain indicators exceeding the national standards to the city's Food and Drug Administration.

Five were closed by the FDA for not having a business license, while another five were ordered to come up to code.

One of store in Pudong New District was selling products containing nearly 10 times the allowed level of aluminum residue, which is 100 milligrams per kilogram.

Nine restaurants, including two branches of Xinya Dabao, were blacklisted for not changing the cooking oil regularly.

Tests also showed youtiao from a KFC outlet in Yangpu district contained the highest levels of saturated fatty acid — the excessive intake of which can lead to cardiovascular disease and obesity.

The average amount of saturated fatty acid contained in samples taken from the 29 restaurants was 3.5 grams, but the KFC product contained 6.8 grams.

In addition to KFC and Xinya Dabao, branches of McDonald's, Yonghe King and Taoyuan Village were also inspected.