One tip that I have found to determine what I should and should not eat, is to record what I eat during a given day. I actually hate doing this, so it takes dedication to make sure it really happens. But it will reveal what kind and how many calories you are consuming. What I found was shocking and scary and it revealed that some drastic changes needed to be made. It's all about choices. If you want to lose weight you need to choose good food that will fuel your body, not just fill it. And believe it or not, once you make the right choices for a while, you will naturally crave the right choices. Those salty, fatty, sweet, calorie laden choices won't taste as good and they used to. I am living proof of that. God will change your taste buds. I know that sounds a little ridiculous, but if he is leading you to lose some weight, don't you think he will take care of that detail too? He can and He will, if you LET HIM!!
There are many websites that help you calculate how many calories you should consume for your height, weight, and age. So do some research and get a plan. If you have a plan and know your right food choices, you will have a better chance at succeeding. I know if I have a plan, and prepared for the snack attack or the perpetual question, "What's for dinner?", I am less likely to make an unhealthy choice.