Use a calorie counting app like lose it. Log everything you eat. It's very tedious at first but pretty soon you get really good at judging how many calories are in things. Don't stop logging! Track your weight. When you hit plateaus zoom out on the time scale and look at your trend line going down and feel good about yourself.

The trick is being honest with yourself. There are no free calories. Those 2-3 little cookies you had at work? They count. The extra scoop of rice? That counts. Most people have no concept of how many excess calories they're really taking in.

Over COVID lockdown my wife and I both gained 10-15 pounds and I was already a good 20 pounds over where I wanted to be. We both started this and never stopped. I lost 40 pounds in about 9 months (230 to 185) , she lost 20, 155 to 134, and we've both kept it off for the last three years. We log all our meals and we exercise. Exercise becomes rewarding because burning extra means you can cheat! Did you bike twenty miles today? HAVE YOU A FUCKIN DONUT THEN!