I eat my breakfast in the morning.
I eat my lunch at 1 pm each day.
I have my dinner at 8 pm on the dot!
I don't like skipping a meal.
I have my morning tea at 10:30 am.
I enjoy having a cup of tea at 3 pm each day.
I usually eat late morning
Just before midday
Of cour5se, you could say: "I eat a meal in the morning,' but the time just before midday is 'late morning,' and 'in' is not required here: "I usually eat late morning."
You could also say, "I eat just before midday."
'AM' describes 'morning' as opposed to 'PM' but as this period covers 12 hours, you could better pinpoint the time you eat by just stating the approximate time at which you eat:
"I eat a meal around 1130 am."
am = ante meridiem. :being before noon —abbreviation a.m. First Known Use: 1563.