Actually there is some research that says 1200 calories per day will increase longevity.
Citation what? I provided a link to the article.
There is no magic number. Whatever it may be, this figure works out to an equilibrium with one's basal metabolic rate accounting for age, sex, general health, and physical exertion level, just to name a few. One does tend to "stay hungry" when they are in that "zone", whereever it may be. For example, for me at one time, maintenance was over 4000 calories a day. That's not counting the midnight snacks needed to satisfy hunger pains that'd wake me up. Now, things have changed, and I'm hovering between 2000 and 2500.
The article is long enough without taking into account 'every' inividual situation and has already factored in gender at least. The general premise seems to be that reducing calorie intake .....
"Her daily calorie count hovers around 1,200 if she's not exercising; 1,600 to 1,800 if she runs 5 or 10 miles on the treadmill. She's also on a local roller derby team. When she's in training for that, she might help herself to a few extra morsels."
...... increases longevity.
According to the article, the average male couch potato is taking in 2500 calories per day. Of course age and activity level come into play ... this is both explicit and implicit. It is up to the reader to make inferences.
And I am curious .... what the heck were you doing when you needed to take in 4000 calories per day? If it was a fire-breathing dragon you were slaying .... well, I guess you slayed it inspite of midnight snacks when dragons are most active?