There are more than 10 different foods or drinks found in the game:
Fish Dumpling Skewer
Chicken On A Stick
Curry Chicken Balls (Next to the undercover HQ in North Point, next to Spicy Squid in Aberdeen)
Spicy Squid (Next to the Massage Parlor by Fish Market in Aberdeen)
You can find most of these in the Night Market. There are plenty of food stands, drink vending machines, and tea shops all around Hong Kong. I suggest making a check list of the foods and drinks you have consumed already.
Here is a great video guide by Predni showing you all different location of food & drinks.
LOL. Just 1000G'd the game and this was my last achievement. I was missing the Waffle Eggs. Look at North Point's Waterfront, then go north to the car dealership and car park, the Waffle Eggs are just outside the building north of those two.