I was basically looking for some proof of this. She has used the app (myFitnessPal or something) for 6 months and has lost a lot of weight, so she swears by it. I've told her "look, I am pretty sure you are at a threshhold that you aren't supposed to go below ever to function." I thought I read before on some website where it listed absolute minimum calories that regardless or any information people told you never to go below. I thought it was 1200 for women, but I can't be sure and my work is blocking weird websites.
If I have proof and make her look she might listen. Right now, even though she's hungry and is skipping lunch - she's still following the 1200 to an exact amount every day. If she goes 100 over she gets upset.
The kicker is, at this point she's wanting to maintain her weight because she just got her dress finished and we get married in ~1 month. Even though she's trying to maintain, she's still eating only 1200. I'm not sure the algorithm, but I'm pretty sure what the app is doing is going "she needs 1700 to maintain, to lose weight you need to cutout 500 calories each day = bam 1200". Or it might even be actually lower for her maintenance, something like 1500 would make sense, and since you don't want to go below 1200 that's what it's setting it at.
Sorry, long post. Just looking for a study or some kind of information on this.