A square meal
Definition 1 of 1
Pro Tip 1/3Satisfying Meal
The phrase goes beyond quantity to imply a meal that leaves you content and nutritionally fulfilled. 
The small portions at the fancy restaurant didn't make for a square meal, so I was still hungry.
Pro Tip 2/3Colloquial Use
Primarily used in casual conversation rather than formal writing or speeches. 
I can't wait to get home and have a square meal; airport food just doesn't cut it.
Pro Tip 3/3Not Just Fullness
A large quantity of food doesn't necessarily constitute a square meal; balance is key. 
Eating a whole pizza may fill you up, but it doesn't count as a square meal.