Eating Jellybeans gives the character 2 and 5 upon consumption and then starts the regenerating effect of 2 every 2 seconds for 2 minutes, for a total of 122 Health. Eating multiple Jellybeans will not stack the healing effects.
Wigfrid is capable of eating Jellybeans, despite it not being meat.
Jellybeans are a good upgrade to common healing foods such as Pierogi or healing items such as the Bat Bat and Healing Salves, as each Bee Queen kill yields between 2160 to 3240 HP worth of jellybeans depending on if the crown is deconstructed or not.
Wormwood is capable of healing from Jellybeans, minus the first small initial health bonus.
The other food he's able to eat in order to regain health is the Grim Galette.
Jellybeans can be Seasoned by Warly, creating useful buff consumables that do not spoil.