Table 1.

Items captured by the survey instrument for assessing stores

Item	Rationale/how measured
Date	Essential food establishment data that allows for identification, geocoding, and time stamping.
Survey start time, survey end time
Food establishment name
Street address
GPS reading
Hours of operation
Type of store	For classifying the stores (13 possible types). Categories are modified from those developed by the North American Industrial Classification System (NAICS) [29] used by the United States to classify food establishments. Specifically for Chinese context, even though both are selling cooked or prepared food, a deli is attached to a restaurant, and a take-out store is a stand-alone store. Check all that applied.
Wet market, supermarket, small market, convenience store, convenience store attached to a gas station, deli, take-out, bakery, street stand/cart, dessert/fruit juice, tobacco/alcohol shop and others
Store size	Possibly a proxy for food variety. Estimated by assessing the length of a single floor tile and counting the number of perimeter tiles of each rectangular section of a store. (All stores had tiled floors)
Length and width
Types of items sold	For assessing the availability of basic food items. Nine basic food items were assessed. Food item categories were determined by in-person store visit and consultation with local collaborators.
Soy products (raw), packaged foods, frozen meals, fresh cooked/prepared foods, basic grain products, processed/preserved dried meat and seafood, cooking oil, cleaned/easy-to-cook/combo meals, and cold desserts/ice cream
Indicator food items	For assessing the availability of specific food items that are indicative of either a healthy or unhealthy diet. Fourteen indicator items were assessed. If available, shelf space and product location were further assessed (see below).
Salty snack, sweet snack, sweet drinks, alcohol, milk/yogurt, bottled water, powdered drinks, tea, instant noodles, pastry/baked goods, tofu products (packaged snack), fruits, vegetables and fresh meat/poultry
For indicator food item that is present:	Shelf space assesses whether the indicator item occupies a significant amount of shelf space (significant or not). If certain products occupy more than half of the shelf space, it is counted as significant.
Shelf space and product location	Product location assesses whether the location of the item is in the front, middle, or back of the store.