For those of you wonder: Who would do something like this? I have a possible explanation.

People who suffer from Binge Eating Disorder (which is characterized either by binging without purging through laxatives or vomiting) sometimes engage in this form of behavior when their illness is extreme. Behavioral addiction isn't something we as a society like to talk about. We think that everyone who overeats has as much control over their consumption as we do, and in a lot of ways that might be true, but that's not the way mental illness works--and this is a mental illness.

Addiction and mental illness go hand in hand, and in the case of eating disorders, the two can be inextricable. As with any psychological disorder, there's a lot of shame involved in behaviors like stealing, lying, and being secretive about one's actions. It isn't that they don't know what they're doing is wrong, it's more so that they feel powerless to stop it. In many cases, the compulsion to overeat might be as strong as the compulsion for someone with OCD to engaged in behaviors that they "have to" engage in in order to feel "comfortable". Think of it as an itch that has to be scratched, and you can't necessarily predict when that itch will hit. Maybe this person IS bringing their own lunches, but then a binge episode comes on, and they believe they are powerless to stop it, even if it means being a thief. The cycle of shame and guilt thus repeats itself endlessly until they get help. Frankly, putting laxatives in food might not even deter them. People with BED have been known to pull food out of trash cans to eat it, and that step usually comes prior to stealing.

So yeah, this person might have the means, and they might have the money, but a better question is: do all people that do bad things do them because they're assholes? Probably a lot, but not all...