I was a nurse, often overweight, mostly stressed, usually very tired, often had cancelled/non existent mealbreaks, changes of shift without notice, cancelled leave, study to do when off duty, own family to service, traffic to contend with, 2 sets of older, ill parents to nurse - because you're a nurse the rest of the family expect it, low pay, high mortgage interest, couldn't afford holidays or even days out.
Did I ever let my patients down- NO.
Did I eat the wrong things - YES.
Sorry but its not a job you can do on 1000 calories a day. Health professionals put their patients first not their own health.