Food doesn't matter, it's the macros that do (protein/carbs/fat) and how much of them you eat. What type of food you eat and how much of it depends more on what portion sizes you enjoy, subjectively and how full you'd like them to make you. If you still wanna eat a lot, you'd wanna stay away from calorie dense foods.
Losing weight (vs gaining weight) is a matter of overal CALORIES. A caloric deficit creates a situation where your body burns mass. This deficit can be created by either eating less, or excerting more energy (exercising, or any activity for that matter). This mass can be mostly fat or muscle depending on how you approach it. If you want to KEEP muscle, you should just lift heavy the way you are and eat a lot of protein. Lifting heavy signals yoru body that it needs those muscles and eating lots of protein will help spare your muscles from being burned up.
Essentially, to lose weight, you should do EVERYTHING you're doing now, except eat less calories. Except, you should still eat enough fat to stay healthy (0.40/0.45 grams per lb of bodyweight) and enough protein to keep your body from burning muscle from workout (a little more than 1 gram per lb of bodyweight). So you'll wanna decrease your carb intake, any carb, until you're in a caloric deficit.
Read this carefully and calculate how many calories you need. Using the numbers I gave you for fat and protein, you need to eat around 76 grams of fat and 190 grams of protein each day. The rest should be filled up with carbs. You should be losing no more than 1 lb and no less than half an lb per week. If it's more or less than either, adjust your calories! And weigh your progress once per week on an empty stomach (and an empty colon :p) at the same time to gauge how you're doing.
There's no specific fattening or trimming foods. Protein does help raise your metabolism slightly, as do fibers, but generally it's more about what macronutrient you eat (protein/carb/fat).