1) You need to be in a calorie deficit. (consuming less calories than you use)
2) Use a calorie calculator to find out roughly what your maintenance daily calorie allowance is. (eg http://www.freedieting.com/tools/calorie_calculator.htm)
3) Eating less calories than this will result in you being in a calorie deficit and losing weight.
4) Every ~3500 calories under maintenance will result in 1 lb weight loss (so eating 500 less calories than maintenance per day will result in 1 lb/week)
4a) Likewise when bulking 500 calories per day above maintenance will mean you put on 1 lb/week (approx).
4b) 250 calories under maintenance per day, 1750 per week and you'll lose 0.5 lbs in that week. (You get the idea..)
5) A slightly higher protein diet will help hold on to muscle mass while cutting this weight.
6) Muscle mass helps loss weight because the more of it you have the more calories your body consumes.
7) Some general recommendations on macros (protein = 4 calories/gram, carbs = 4 cals/gram, fat = 9 cals/gram)
- protein: 0.6g-0.8g/lb of body weight - fat: 0.4g-0.6g/lb of body weight - carbs: fill in the rest of your calorie allowance
Example for 200 lb male trying to eat 2200 calories;
protein: 200 x 0.8 = 160 gram | 160 x 4 cals = 640 cals
fat: 200 x 0.5 = 100 grams | 100 x 9 cals = 900 cals
carbs: 900 cals + 640 cals = 1540 | 2200 - 1540 = 660 | 660 / 4 cals = 165 grams
Therefore the 200lb male will consume 2200 calories by eating 160g of protein, 100g of fat and 165g of carbs.
When and how these calories are consumed doesn't really matter unless your really care about athletic performance.(1-2% to be gained maybe in meal timing and nutrient partitioning) So eat how and whatever you prefer. If that means 1 huge meal or 5 small ones no problem.
I'd recommend a balanced diet consisting of fresh natural foods. Also 1 hour of exercise per day (some days cardio, other days weights(focus on compounds; squat, deadlift, bench press, shoulder press, pullups, rows)).