I feel there is the wrong attitude around the quantity of food.
First off, food should be appetizing and the amount of food on your plate that feels appetizing will be determined by your appetite (read: appetizing).
Food either matches the fire, or it puts on some theatrical masks and becomes your mother, partner, loneliness, frustration, insecurity, boredom. In that case what we need to do is resolve those relationship issues separately, outside of food.
We need less food than we think since the sense of satisfaction comes from the digesting ability of the body, not the quantity of food. However, restricting the amount of food on our plate (under the crucifixion of dieting), WITHOUT attention to increasing digestive fire, will cause such a vacant hole in the body it will panic and want to fill it more than before.
Repeat: your sense of satisfaction comes from the ability of the body to digest your food into stable tissue, not the quantity of food on your plate.
And for those that need to put on weight (I have personally be here at times), I would like to suggest that it's not more food you need (perhaps the type of food is important) but more rest, more letting go, more fun, more surrender.
Every time to sit to a meal, look at it and think on how you feel inside. Are they a good match?