This will seem really controversial, but it's the truth, hear me out for a second: You don't get to decide how MUCH you eat! I know this sounds crazy, but it's absolutely true. Every living being whether it's a human or animal takes in precisely the amount of calories that the body says it needs.
here's the mathematical evidence: Over a 30 year period, this intake has to be incredibly precise. In 30 years, you take in about 22 million calories (assuming 2k per day). Now, if you're off by even 5%, say 1m calories then you would gain or loose 300 pounds!! (at the well known 3400 calories per pound) The vast majority of humans and even animals, don't count their calories, so how can they eat exactly the precise amount of calories to be able to sustain roughly the same weight. The reason of course, is because while you may not be counting your calories, your body certainly is, and counting them much more precisely than you or I can. IT adjusts the amount of calories you consume to reach the target weight. Now that target weight is decided by your body's set point - YOU can not change it. If you're body tells you to eat, you must eat. And you can't just trick it by eating a ton of super low calorie spinach.
Now, you may be able to reduce your caloric intake with sheer willpower, for a day or a week, or a month or even a year. But, the body will always be trying to compensate for this. And unlike you, who will grow weary of fighting this war, biological processes don't get tired. They fight and fight just as effectively 1 year later, 5 years later or even 20 years later.
Try this experiment: just once, try to eat half the lunch you ordinarily would eat. I bet you can't do it. Just try it. And if you could do it, you would quickly realize how miserable the rest of your afternoon would be.
Everything we've done: trying to reduce our caloric intake to excessive exercising as far as loosing weight is concerned is sort of a hack. What you really want is to reduce the set point. Once you reduce your set point, loosing weight will be completely effortless. If you look at all the normal sized people, all the epdimelogical studies show: they don't excercise more and they don't eat better, their bodies simply have the correct set point.