Connected on LinkedIn to a PT that I used to use back when I was clueless. She just started a discussion asking about a nurse client that has trouble getting food in while working. Some of her trainer buddies' responses are lulzy:
She needs to change her attitude about eating at work, so that she doesn't end up binging when she gets home. She is a nurse, so you may want to appeal to her with information about basic nutritional science she may not be aware of.
During an 8-hour shift she probably should consume a full meal in addition to plenty of healthy snacks.
As we all know the body's reaction to not being fueled properly is to slow metabolic processes so that the body runs on less calories. This will result in her body holding onto fat and metabolizing muscle. When she binges in this state she will store more calories as fat. She will continue to change her body composition in the wrong direction (less muscle, more fat) if she doesn't start eating regular nutritionally balanced meals.
She may not be able to control her work/ sleep schedule, but she can control her eating.
Processed foods and supplements are not the answer unless it is the only way to get her to eat due to time/convenience concerns. In this case steer her towards healthy options.
And for gods sake absolutely don't let her eat based on a low-carb/no-carb diet, or fasting! Unless you want to get Uber-fat and have greater weight control issues in the long term. She needs all the carbs she can get running around on a long shift for both her body and her brain!
Focus on getting her to eat; when she begins to have the energy to exercise, you can start to think about shaving 250 calories a day from her diet for weight loss if she needs it. If she exercises in the state she's in right now she probably will cannibalize her own muscles. She needs to EAT!
If you're able to fix the eating problem get her on a resistance training regimen so that she can build some muscle and raise her resting metabolic rate.