For this achievement you need to consume every food item in the game. There seems to be a bit of confusion surrounding this achievement and I hope I can clear some of that up with this guide.
• You do not need to purchase anything extra that is not a food item, they do not count toward this achievement.
• For items to count make sure you actually consume them. So when you purchase them from a store do not take the food "to go", eat it there and then.
• You do not need to complete that level for the food to count, once you've consumed it you can quit back to the map.
Now with that out of the way, here's a list of the food you need to eat, where you get the food from and how much it costs.
Level: The Shopping District
The first 4 stores in this area are at the start of this level, they're in a line at the top of the street.
Delicious Cup
• Tea - $1.40
• Coffee - $1.60
• Espresso - $1.60
• Hot Chocolate - $2.50
• Iced Latte - $3.75
Dee's Tex Mex
• Nachos - $7.75
• Tacos - $9.85
• Burrito Grande - $11.25
• Quesadilla - $13.50
• Fajitas $17.95
Mini-Marts
• Chewing Gum - $0.95
• Chocolate Bar - $1.25
• Cola - $1.80
• Grape Juice - $2.25
• Energy Drink - $2.95
Sushi Bar
• Miso Soup - $2.50
• Avocado Hosomaki - $2.50
• Salmon Nigiri - $3.85
• Ikura Don - $4.60
• Rainbow Maki - $8.75
Continue through the shopping district until you enter the tunnel. Once you've entered the tunnel walk down the sloped entrance and keep an eye on the wall, one of the wall blocks will have a black star on it. Walk up to that section of wall and an entrance will reveal itself.
Wallace's Mystery Shop
• Tlaloc's Feast - $49.95
• Ambrosia - $59.95
Level: Casa Loma's Film Set
This store is right at the start of the level. Once you've defeated the immediate enemies that start on the screen with you progress a little and enter the wagon.
Fancy Chip Wagon
• French Fries - $1.80
• Poutine - $3.50
• European Hot-Dog - $3.80
• Buffalo Burger - $5.80
• Croque-Mineieur - $6.50
Level: Leo's Place
From the start of this level fight your way through the enemies until you see something at the top of the screen that looks like a merch stand. There's a curtained doorway and a sign above it that says "Leo's Store", enter the doorway for the next shop.
Leo's Place Stand
• Carbonated Water - $0.60
• Classic Potato Chips - $0.95
Level: The Frying Tengu
For this store you'll need to progress quite a bit into the level. Keep working your way through the level until some ninja's burst through the floor, from this point keep working your way forward but keep an eye on the top of the screen. The store is quite obvious, the doors are wide open and there's a rug in the doorway.
The Frying Tengu
• Ramen - $5.95
• Udon - $5.95
• Tempura Vegetables - $5.95
• Tempura Shrimps - $5.95
• Kushiyaki Moriawase - $14.95
Level: Fire Escape
From the start of the level you need to move forward a screen and you'll see a welcome mat on the floor, walk through the sliding doors for the next store.
Scott's Dad BBQ
• Iced Tea - $0.95
• Tropical Punch - $2.25
• Kebab - $4.95
• Hamburger - $4.95
• Filet Mignon - $18.95
Level: The Park
This is the most hidden shop in the game. Progress through the level and pay close attention to the top of the screen. Not long after picking up the key you'll see 4 NPC's standing around, Walk up between them and you'll be transported to a brick room with a doorway on the other side of the room, through that doorway is the store.
Mobile's Secret House
• Herbal Tea - $1.60
• Wild Blueberries - $2.95
• Ginkgo Biloba - $9.95
• Sautéed Shiitake - $9.95
Level: Techno Base
You'll need to progress quite a bit into the level to reach this store. Once you've defeated the 4 blue haired girls and the 2 flying guys keep an eye on the top of the screen. As you move forward you'll see a big metal door with a "F" to the left of it and 2 lights above it. Approach and walk through the doors to enter the store.
Techno Shack
• Food Pill - $2.50
• Beef Jerky - $2.95
• Energy Tank - $3.95
• Microwave Chicken - $3.95
Once you've consumed each of those items at least once the achievement will unlock.