For some time I have lived on around 1000 calories, so after slowly losing weight, I increased calories to 1200 per day.
At that point, I also changed the way I drink water.
I used to drink water often in smaller amounts.
Now I drink water twice a day in larger amounts at once.
After doing those 2, I stopped losing weight.
Apparently, 1200 calories is enough for me.
And my mood has been good ever since I reduced amount of food I eat.
It seems that my bad mood in the past was result of eating more food than I need.
Now, there were certain flaws in this experiment.
The most obvious flaw is amount of calories in food.
Only certain foods have exact calorie number on them.
For other foods, I had to rely on data about it from internet.
The other flaw is that I wasnt able to keep up with one meal per day, but often I practiced one big meal per day and one much smaller one later.
But regardless, this experiment yields fantastic results.
It stands as opposition to overeating.
I stated before that overeating also makes person happy, which is true because if you eat way more food than you need, you feel happier.
But this experiment seems to be more effective because not only I feel better than when overeating, but I enjoy food more.
So to sum it up, there is:
1. Eating 1200 calories, which feels better than overeating
2. Eating a lot, but not overeating (causes bad mood)
3. Overeating, which feels good
It seems that the option 2 is the worst, option 3 is second best, and option 1 is best, as conclusion of the experiment.