Hi,
as I'm often in JFK:
In the late afternoon the swiss lounge in JFK offers a warm dinner starting 4 or 5 pm.
Whole day there are a salat buffet, a selection of nice cheese and other snacks available, additional full bar self service.
In terms of food I prefer LX over the LH lounge in T1 (SEN compartment), as LH mostly offers only snacks, although there are warm snacks in the evening, but not a full dinner. The bar with bartender is a plus for LH, also the restrooms and showers.
But since the A380 is operating to JFK the staff lacks to keep the buffet fully maintened because of the large number of guests.
A few days ago for the LH401 (departs at 3.40 pm) only vegetables and some sandwiches where available.
Regards,
taigatrommel