There are infographics and whatnot out there detailing the caloric density of different kinds of food, that make it clear that, depending on the diet you already eat, you can reduce your calorie intake by vast amounts just by switching up what kinds of food you eat. But it's potentially a more expensive way to eat, and probably a more time-consuming one if you don't already enjoy cooking.
It does NOT work well at all. Don't get me wrong, it helps a little, but your stomach is extremely smart and it knows alot more about calorie counting than we do. Like it or not, it keeps it's own account of your calorie intake and adjusts your hunger and appetite accordingly.
If you're like me and you're already eating a very healthy diet and you exercise regularly and your still gaining weight, you only have one option: go hungry. Very hungry. Right now, it's the only way. You could exercise a lot more, but either way, you're going to suffer.
Even with not microwaved but easily made, pre-made soups or veggies are easy to heat and more filing.
Even eating only snacks I can stay under 1.5k per day by just not eating anything on the side.
The trick for most people starting is to not drink your calories: switch to 0% calorie sodas and replace sugar in coffee and tea with aspartame. No fruit juice and check calories as "0% added sugar" usually mean there are a lot of calories.