They weren't just there for window dressing, either. The game's designers (and the products' PR departments) wanted to make damn sure you associated these endorsements with peak health of both body and mind. To that end, they turned chips and soda into power-ups that could restore your health and psyche, the latter being the game's measurement of how quickly your body can naturally heal itself. So they're essentially saying you will die if you don't rabidly consume those chips and soft drinks, but they don't stop there: Should you actually die with Doritos or soda in your inventory, they will bring you back to life. As far as Peace Walker is concerned, junk food is the new Jesus Christ.
That one bag can feed 5,000 mercenaries.
Then there's AXE Body Spray, which improves your psyche gauge by making you smell better. That's how they reconciled including a product that wasn't even around in the '70s (when Peace Walker takes place). Pretty thin justification -- but not as thin as you'll look in this slimming black AXE T-shirt!
Perfect for repelling any female enemies.