The first thing you need before a diet plan can be planned out is to find out what your caloric needs are based on your current height, weight and age. Start by going to this site and plugging in your information to find your current BMR (Basal Metabolic Rate).
As an example I will use my stats. I'm 33 next month, 185lbs, and 5'11". My BMR came out to ~1896. This number is essentially the amount of calories my body burns with an activity level of 0, or completely sedentary. Now I will apply the Harris Benedict Equation to my BMR which will determine how much I truly need to consume in order to maintain, I say again, just to maintain my current weight.
Once you figure all this out, then we can get into more details on what to eat, and when to eat.