Food paste appears as a cafeteria tray with a blob of pink paste on it. It replaced all forms of food at Suffolk County charter school as an experiment to help fund the school through a program called the Nutritional Alternate Paste Program (NAPP).
Holotapes found in the school suggest that the paste is completely devoid of flavor, turns skin pink with regular consumption, and has psychological effects such as irritability.
The area that this consumable is found has a unique population of "pink" ghouls, which supports the observation of the paste turning the skin pink.
One can find dead raiders with a letter on them regarding the paste as a random encounter. This note mentions that one of the raiders has become addicted to the food paste, and that they are having an intervention. This suggests that the food paste has some addictive qualities.
No matter how much paste is consumed by the Sole Survivor, they will never experience any of the side effects of food paste consumption.
Possible relation to Thin red paste from the Big MT. Similar effects of 60 heal and +5 Max HP.
The food paste as a whole is a reference to Pink Slime, a food additive consisting of low-fat meat which was ground into a paste. It's particularly infamous after being widely used as a meal alternative in American school lunches during 2012, which resulted in major controversy.