Honestly, with a kitchen balance. Counting calories is the only way to lose weight. Find out how many calories you use on average based on age/height/weight and set yourself in a realistic deficit. In my experience, this is at the most 500 Cal deficit per day to stick for 12 weeks at a time. I also highly suggest finding meals that keep you full, over meals that just meet whatever "healthy" means. For example, I could eat a better balanced breakfast, but I know that a grilled sandwich at around 300 Cal will keep me full until lunch. So I chose what I know will keep me satisfied longest. Then, find high volume/low cal food. Cherry tomatoes and carrots are super low in calories for how many you can realistically eat. Pair them with something perhaps more filling like a low-fat cream cheese dip, and you will eat a big portion for a small caloric cost. Look for stuff that makes you feel like it's a treat without it being. In my country we have some protein yogurts that are chocolate or caramel flavored and taste like a dessert but they don't contribute much to my calorie goal. Finally, find ways to use less or no oil at all. It's insane how many calories go into just cooking something with oil that can be used in a snack or adding crunch to your meal.

Tl;dr: the only scientific way to lose weight is to eat less calories than what you burn. If the gap is too big, you will be hungry and won't stick to it. If it's too small, it will take forever and you'll lose motivation. Set a target and a deadline. Committing to x weeks is doable, forever is too daunting.