My parents were married in 1956. Aside from being college students and dirt poor, they ate very modestly. We lived in the Upper Midwest. This sample menu would have been when they moved to an apartment where they actually had a stove. They started out married life with a hot-pot, an electric frying pan and a coffee maker. They cooked on the floor.
For breakfast, they would have toast with butter, a doughnut and some black coffee, maybe a piece of fruit, like a banana. Sometimes oatmeal with raisins. The doughnut was dipped in the black coffee for taste--um, yum?
For lunch, my mom would make a fried egg sandwich, soup, or a piece of fruit. She was pretty skinny back then. My dad would have brought a bag lunch to his office job consisting of a sandwich (whatever was on sale, like bologna, liverwurst/braunschweiger) on buttered bread, a piece of fruit and a canister of juice or coffee. Sometimes he would be expected to take business lunches and would have had something like liver and onions for dinner. He STILL orders liver and onions when he has the chance. My mom won't touch that now!
For supper, they might have had a small roast, pork chops, or baked chicken, potatoes or rice, and a small salad or a side vegetable. They'd also been "introduced" to pizza and might have had that once or twice a month, along with spaghetti. My paternal grandma used to send my mom recipes to try, things my dad would enjoy.
As the kids came along (there were 6 of us altogether), our meals didn't change much. In the early 1970s, my mom was still preparing breakfast and lunch much as she did in the '50s. Dinners became a little more elaborate as she experimented with gourmet cooking and Julia Child's TV program. She always served a variety of foods. I know some families from the '50s and '60s that did not vary from their weekly fare (cold ham sandwiches on Sunday, pork chops on Monday, liver on Tuesday...) Can you say BORING?
We always ate dinner together at the family table, and we always prayed before eating.
Sure hope this helps.