A "monomeal" is a meal that consists of just one type of food. Usually raw fruit or veg.
Like a load of orange slices.
Or a pile of bananas.
Or half a watermelon.
There's also a thing called "banana island" where you eat nothing but bananas for days.
It's huge on Instagram. Thousands of photos tagged #monomeal have been uploaded.
So what's the justification for monomeals? Some people think eating a meal with more than one food in it overtaxes the digestive system by making it multitask.
And that this can cause something called "leaky gut syndrome". (The NHS says there is "little evidence" for leaky gut syndrome and it is not a recognised medical diagnosis.)