I think the food in coop is dependent on keeping arrangements.
If you have a secure coop and run (I'm thinking rats and mice) then leaving food 24/7 is probably fine.
I can't do that here. I can't even leave food down during the day. The coops are open during the day and everything here it seems will eat chicken food.

Another aspect to this is being hungry in the morning isn't necessarily bad, or abnormal for any creature. I'm hungry in the mornings.

My view is if the chickens go to roost with a full crop then that is good enough.
The pullets here metabolize their food fastest which is to be expected; they're growing.
The senior hens tend not to show being particularly hungry most mornings.
Then these is also a marked difference between what is considered underweight in the US for example and what is considered underweight here.
Another aspect to this is that if you feed free range chickens they tend not to forage as much. There is a balance when free ranging. My view and the view of most free range keepers here is that assuming forage is decent the chicken is healthier eating what it finds foraging than it is eating the commercial feed. I think Centrarchid has a similar view with his flocks.
The down side is a foraging chicken is often more obvious to predators.
In the Spring and some of the summer I only feed commercial feed twice a day. In the winter months I feed three times a day.