Is there a food or drink that you have often? Something you have every day, or several times a day? Something "you can't live without?"
Is that repeat item healthy? Or unhealthy? If it's not so good for you, then you may want to consider cutting down on it, or eliminating it altogether. (Sodas, desserts, fatty snacks, a lot of meats, cheeses are some potential candidates.)
I used to have desserts several times a day. Cakes, pies, cookies, and tons of ice cream. That pattern of consumption alone put hundreds of pounds on me over time. When I stopped the negative habits, the weight poured off and has stayed off.