I wouldn't call 1500 calories a day barely eating, unless you're extremely active (several hours of high intensity exercise a day). It's on the lower end of normal for a normal/ fairly active lifestyle, a smack dab in the middle of normal for a sedentary lifestyle (working in an office or sitting in school or similar, driving or catching a ride to&from most places, mainly sitting during off hours; most exercise about 20 minutes a day).
Nutritional needs do vary hugely depending on activity levels, medical conditions, age, & sex. The 1500-2500 kcal per day is a maintenance level for the majority of people with a moderately active lifestyle. So I'd very much recommend working with a nutritionist to figure out what your personal caloric & nutrient needs are.
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Personally, when I'm at my healthiest I'm generally eating 5-6 small meals a day... But -just looking at calories, which is only a small piece of overall nutrition- that ranges from 500-1,000 to 20,000-30,000. The difference? 500-1,000 are days spent at home playing with the kids & watching movies, and the 20k-30k are 10+ hours a day doing snow sports in winter (yay 6,000 kcal winter ration meals :wtf: ). I can very easily be gaining weight on 500 kcal per day, and be struggling to keep weight on at 30,000 kcal per day. The difference is primarily activity level (the demands I'm placing on my body); but also metabolitic aka if I'm not meeting my expenditure needs my metabolism slows way down, very very quickly; as well as content (I've had kwashiokor a few times, eating more than enough calorically, but not complete proteins, I've ravaged my bones not meeting mineral needs, lost my eyesight due to vitamin deficiencies, etc.); and also temp. One burns a lot more calories staying warm or cooling off. Homeostasis isn't difficult to maintain in temperature controlled environments, but ones body has to work very hard to stay at temp in cold/hot environments. People who spend all day outside in below freezing temps and in above 100 degrees, again, have very different nutritional needs than those who spend all day in houses & buildings.
When I'm deep in disordered eating, I may only be eating a once or twice a week, and only a few hundred calories, tops. But just as destructive -although with a longer reaction arc- is when those numbers aren't matching my activity levels. It might look good on the surface, but getting down to brass tacks is an entirely different story. Starving during high activity, and/or overconsuming during low activity levels wrecks my system. Which is super touchy due to years of misuse. Ditto various forms of malnutrition.
So, yes, this is something I've dealt with a lot over the years... For a lot of different reasons. Some trauma related, some disordered eating related, some lifestyle, some medical.
