Glad to see you're taking steps to improve your health! To begin with, I'm not a doctor or nutritionist so YMMV.
The first thing you should do is throw out any books or magazines that promise quick results or tell you not to eat X and only to eat Y. Very few people can stick to such a restricted diet for the rest of their life and as soon as you go off, chances are it'll all come back. Or you'll feel guilty every time you indulge in forbidden foods and that's no way to live!
How many meals do you eat in a day and what size of meals.Generally it's best to eat 5-6 smaller meals a day. The reasoning behind this has to do with how your body processes the foods we eat. When you eat a meal, your body will turn carbohydrates into blood sugar. Your body regulates the blood sugar levels very tightly. In order for your body remove sugar from your bloodstream, it wants to store the sugar in the muscles as a form of energy called glycogen. (More on how that gets done in a second) There is however, a finite limit to how much glycogen your body can store in the muscles. The problem with this is finite limit is most people already have their glycogen tank filled up! Meaning, the body can't store anymore glycogen in the muscles. So your body has to find another way/place to store that sugar. In this case, the sugar is turned into fatty acids which is stored in fat cells around the body. So, basically it's stored as fat. But wait, it gets worse!!
As I said above, the body wants to remove sugar from the blood stream to stabilize blood sugar levels. The way this removal and transportation is actually done with insulin created by the pancreas. A high blood sugar level results in lots of insulin being produced. When lots of insulin is being produced, our body thinks that plenty of energy is available and that it should
stop burning fat and start storing it. But wait, it gets worse!!
Eventually these insulin levels have to come back down. And normally they drop below where they should be. Feel tired after eating a big meal? That's because your insulin levels are too low. When insulin levels are too low, you feel tired and hungry and you crave....high sugar foods. And if you go grab that chocolate cake or Snickers bar, the cycle starts allll over again.
So, how do we break the cycle? Well, the best way to do this is to eat five or six smaller meals throughout the day. This will keep your blood sugar levels at a more stable level and you wont have the blood sugar "spikes" that occur when you have 3 larger meals and that cause your body to overreact as described above. You can also avoid, as
aevans176 said, cokes. (I lived in the south for 7 years) Foods high in sugar is obviously bad so try and stick with a piece of chocolate cake instead of the super triple fudge brownie chocolate cake al a mode. Also, sometimes "low fat" or "no fat" foods will increase the level of sugar in order to make them taste better so read those labels!
What do you think is the best intake for yourself based on your observations?Now, the next important part of the question is, "how much do I eat?" Obviously 5 or 6 big macs a day isn't going to do the trick. Here everyone is different so you'll have to experiment and possibly get your doctor involved. The best way I've found to determine my meal size is to base it off my Basal Metabolic Rate (BMR) or your Resting Metabolic Rate (RBR). To keep it simple, we'll just say that BMR is how many calories your body burns just to stay alive...breathing, digesting, thinking etc.
You can get a quick calculation of your BMR or RMR here. Now class, find your BMR and I'll show you how you can use that to lose weight. Your doctor can probably get you a more accurate number but I used the website and it works for me.
Now, it's not healthy to lose a lot of weight really fast. So we're going to shoot for 1 or 2 pounds per week. To keep things simple, let's say we want to lose 1 pound per week and 1 pound of fat ~= 3,500 calories.
Now, I'm 6'8, 210 pounds, age 24 (blue eyes, male, and have a job with a 401K ladies

....republicans need not apply

) Based on the BMR calculator, my BMR is 2,230 calories. That means if I sit on my butt all day I'll burn 2,230 calories a day or that I'll need to eat 2,230 calories to keep my current weight. In a week I'll burn 7 times that which is 15,610 calories.
So, for those of you following along at home, take your BMR and multiply it by 7.
Now, as I said, I want to lose a pound a week. So I'm going to take my total calories for the week and subtract one pound. That'd be 15,610 - 3,500 = 12,110. That gives me how many calories I'd have to eat per week if I wanted to lose one pound. Now let's divide that out by 7 days which gives us 1730 calories per day. Now since we're going to eat 5 meals a day, we'll divide that by 5 which gives us, 346 calories*. So each one of my 5 meals should be around 346 calories. Ideally I would separate these meals by about 3 hours. When I have to drop weight for racing season I'll follow this plan fairly strictly and I'll start to feel hungry about 30 minutes before my next meal. However, corporate America and our lives get in the way so it doesn't always work out so well. These are all just guidelines. Try to keep it around 3 hours and try to keep the meals around 350 (or whatever your number is) calories. In the end as long as you're at or below the total calories needed per week (12,110 in the example) you're good to go! Here's the same thing in a formula:
QUOTE
BMR * 7 = calories per week (CPW)
CPW - 3,500 = calories per week to lose a pound (LAP)
LAP / 7 = total calories per day (CPD)
CPD / 5 = calories per meal
Now, of course everyone is different and things aren't always so nice and neat so you're going to have to see what you can tolerate in terms of the size of meals. I can barely handle 400 calories per meal so I jacked it up to 550 and just added an extra 30 minutes on the bike. If you exercise you can eat a power bar or whatever every 30 minutes to an hour while you exercise or just increase you calories per meal. You want to make this something you can live with an don't hate. After awhile you want even notice it. You'll have a pretty good idea of what calories are in foods and how much you can have per meal.
Final tips:
1. Drink water. The more the better. I shoot for half a gallon each day.
2. Exercise. It raises your metabolism, good for the heart etc etc etc.
3. What you eat is still important! 400 calories of french fries isn't as good as 400 calories of carrots. (though you should still lose the weight) I go by the 1/3rd rule. Look at the label of the food. Look at total calories per serving. Then look at calories from fat per serving. If the calories from fat is at or below one third of the total calories, you should be ok.
4. If you want to raise your BMR, lift weights. More muscle increases the BMR/RMR, it's like burning calories constantly for free!
5. The above program assumes you don't exercise (thus violating tip #2

) so you'll have to figure in how many calories you burn from exercise and increase them in your meal or add another or do what you want.
Anyone feel free to send me a PM if you have questions!
Resources:
BMR/RMR calculatorblood sugar and weight lossArticle explain why BMR and RMR don't go far enough A good calorie count page that also ranks food nutrition wiseCalories burned per exercise*This is a low number! 346 calories is not a large meal but the reason for this is because I'm a little below a normal weight for my height because it's racing season and I just finshed a stage race this past weekend, so if your number is a lot higher don't worry!