Forlong of Gondor, and Barliman Butturbur are described as fat and it is only the humans and Gollum (to whom everyone else no doubt appeared fat ) who are disparaging about fatness. In fact the wordt offender is Aragorn who is really quite offensive to Butturbur.
A degree of roundness was clearly considered normal and healthy in a hobbit - as a selfsufficient community vulnerable to the vagaries of harvest an efficient metabolism was an advantage....
And the elves did work according to LACE...... and apart from bread making the cooking was done by men in the main ( some strange intuition tells me barbecuing featured heavily - maybe that is the reason Celebrian shipped out early.... she grew and washed the salads, gathered up the ingredients , cutlery, crockery, made sure there was enough charcoal, rounded up the the kids and later did the washing up - and Elrond just prepares his "special" marinade using every bowl and chopping board in the kitchen), throws the meat on the grill and wonders why Celebrian isn't grateful for him doing the cooking ....
). In fact the reason that elf women developed Lembas as a complete source of nutrition was probably as a necessary response to male elf cookery.....