While holding the food item in your hot-bar/hand hold right click.
Hold Right Click.
right click + hold
Carry the food and then right click.
Chose it in your usable inventory and right click.
Right click the food item and hold it.
Tap and hold on the screen.
Right click without anything it will eat.
Right-Click with the food in your hand.
You don't click, you hold the right mouse button down.
Hold your food, an apple for example, and right click (and hold).
You right click
Same as other drinks and food. Right click, and hold.