>>213007447It's an equation. You need to calculate how many calories you need to eat a day to maintain your current weight, then subtract like 300-500 calories from that amount. You can track your weight if you want. It will fluctuate a bit, so don't worry about that, but look at overall trends. If you haven't lost anything after a month, subtract 100 calories and keep going.
Look into nutrition macros. People who try to "diet" tend to not feel full after meals and by the end of the day they feel like they're starving so when they eventually crack, they binge eat the most calorically dense foods possible. Balancing protein, fat, and starch will help keep meals feeling satisfying, and keep you energized.
https://www.healthline.com/nutrition/how-to-count-macros#step-by-step
You don't have to use the above website. There are tons of them out there that give you a run down and all of them vary slightly, but it's essentially all the same crap. You can fine tune your macros to your lifestyle. Just start somewhere and figure it out.
Once you establish your macros, you'll need to track everything you eat. There are apps out there that help you do this. Some allow you to scan barcodes on labels so you can enter things into your tracker easier. MyNetDiary is pretty good and its free (although they'll annoy you with ads to subscribe to their premium tier every once in awhile). Weigh everything with a scale in grams. It's easier to cheat when you're eyeballing volumes, so weigh everything and don't let yourself cheat. The extras here and there are what get you. Log everything.
It kind of sucks at first, but you fall into the pattern and it gets easier. Doing meal prep ahead of time or pre-cooking ingredients so you can throw things together helps.
All the people who bitch about metabolism are full of shit. Everyone can lose weight, but it's fucking hard and it takes effort.