To examine the extent and characteristics of food and beverage (F&B) promotion in Hong Kong mass transit railway (MTR) stations in districts with different socioeconomic statuses (SES) and school density.

All advertisements located in the eight selected MTR stations were recorded by photographs or videos, and classified into F&B and non-F&B. The percentage of F&B advertisements and unhealthy F&B being promoted, and common persuasive marketing strategies used in F&B advertisements were compared between low v. high SES districts and school zones v. non-school zones.

MTR stations in Hong Kong.

Not applicable.

Of the 8064 advertisements documented, 861 (10·7 %) were F&B advertisements, promoting 1860 F&B items. More than half of the these were unhealthy foods. Stations in high SES districts or school zones tend to advertise more unhealthy items (high v. low SES: 55·8 v. 50·8 %, P = 0·049; school v. non-school: 60·8 v. 49·3 %, P < 0·001). More than one-third of the F&B advertisements recorded did not utilise any of those persuasive marketing techniques that were examined, and using models (13·9 %) or providing discounts (8·8 %) were the two most frequently used non-festival-related persuasive marketing strategies.

Unhealthy F&B advertising in MTR stations is prevalent regardless of SES and school density, and persuasive marketing strategies were infrequently used. These suggest that a ban on unhealthy F&B advertising around schools or the use of persuasive marketing strategies alone would be ineffective in Hong Kong. To align with the recommendation from WHO, a universal ban of junk food advertising should be enacted.