It’s very easy. Just eat only when you’re hungry. And try to eat till your satisfied. I’m 5’8+ but weigh 52-55kg depending on the diet I’m on

. My sister as tall, is 75kg.
I’ve changed from eating everything my parents cooked back in the day to twice a day (very small breakfast, usually full of eggs) with 14+hours between eating, drink loads of water and just eat a low carb diet full of nutrients. 30 minute a day run as well. I recommend fasting as well.
This is actually also good at keeping you feeling young. Humans were never meant to eat 3 meals a day. That’s always been pushed for the sake of consumption. Just think back to the healthiest, peak human condition. It was when our forefathers hunted for their one meal a day or even one meal for 2-3 days.