One work around for this is to eat lower calorie variants of food you already enjoy. Butter alternatives with significantly less calories are a great start. Low calorie or calorie free drinks are an amazing alternative to shaving off unnecessary calories from your daily meals.
The volume of food you eat doesn't always necessarily have to correlate with how many calories you're consuming. For example, you dont even have enough room in your stomach to accomodate for 1000 calories worth of celery. But you could easily accomodate for that amount of calories if they were consume in french fries or something equally unhealthy.
"liquid calories" as they're called are so often the cause of unnecessary weight gain. They're also one of the first things you should look out for if you're encountering issues losing weight.
Spreads and drinks aren't the only things you can replace if you're looking to cut down on calories, though. There are lower calorie versions of flour and various different cooking and baking ingredients.
You don't even need to explicitly use lower calorie variants. There are some common sense and simple switches you can make to your cooking processes to work towards a healthier diet. You can make "diet pizzas" by preparing a pizza on tortilla bread instead of working from a thick dough base, for example. Increasing the volume of vegetable based fillers in various meals will help work towards ensuring meals remain incredibly filling without the extra calories.