Europeans considered the natives who did not have meal time as uncivilized. Civilized people ate at meal time, differentiating them from animals where grazing is the norm.
Pre industrial revolution, breakfast was cold dishes, lunch was a heavier meal, cooked, dinner was similar to breakfast
Post industrial revolution, people work away from home, so lunch became a more casual affair and dinner was the cooked meal
Folks were still easting as much as when they were farming so nutritionists began advising for a lighter breakfast, Kellogs jumped onto this an introduced corn flakes
Then fruit-growers associated sized the opportunity to market fruit juices which contains the newly discovered vitamins
Breakfast is the most important meal of the day, no scientific backing, no effect on metabolism or weight loss
3 v 6 meals, 2 v 5 meals, no weight or hormonal differences
periodic fasting seems to have some positive benefits