The phrase 'hearty eater' is correct and usable in written English.
You can use it to refer to someone who eats large or plentiful amounts of food. For example, "Jill was a hearty eater; she could always finish one large plate and still ask for more."
From "Old Mr. Flood": "I love a hearty eater, but I do despise a goormy".
It still survives in phrases such as "trencherman," describing a hearty eater.
Two thin, rather skimpy, pan-roasted trout fillets ($18), though, left a hearty eater wanting more.
If you're a hearty eater, you'll need at least four dishes to fill up, especially because the lone dessert, mochi ice cream, may not tempt you.
He orders clams Posilipo and the waiter brings him calf's liver, or a small steak and the waiter brings him a large one — which my friend, a hearty eater, devours rapturously, congratulating himself on having found a restaurant with such generous ideas of smallness.
Mr. Clutter enjoyed the chore, and was excellent at it — no woman in Kansas baked a better loaf of salt-rising bread, and his celebrated coconut cookies were the first item to go at charity cake sales — but he was not a hearty eater; unlike his fellow-ranchers, he even preferred Spartan breakfasts.
Appetizers and desserts will each fill two hearty eaters and most entrees are enormous.
Gina Marie's move from its longtime spot in Mount Vernon could have been bad news for hearty eaters.
AMERICANS are known as hearty eaters, so a string of recent food-safety scares has shaken them to their rather wide cores.
The bears -- hearty eaters and intelligent, adaptable animals -- have come to rely on people to broaden their diet of berries, acorns, skunk cabbage, rabbits and other small mammals.
Maisen, 4-8-5 Jingumae, Shibuya-ku, (81-3) 3470-0071, fax (81-3) 3470-6689, specializes in tonkatsu, the breaded and fried pork cutlets popular with children and hearty eaters.
