I just wanted to put in my $.02. I've been counting calories off and on since college and have learned a few things. First, the bigger you are, the more calories your body needs to consume just to keep it running. The smaller you are, the fewer calories you need to consume. So, the theory that someone who is obese needs to consume fewer calories than someone who is just slightly overweight, really doesn't hold true. And it can lead to frustration and binging over time. Someone who is obese and starts dieting will probably need to eat more calories in the beginning and then start to reduce their daily calorie intake as they lose weight if they want to continue to lose weight.
The best way to lose weight by counting calories is to spend a couple weeks just eating normally and keeping track of your calories. Then find out the average amount of calories you ate. That is probably what your body needs to keep it running. Once you know that number, lower it by a hundred or 150 calories. Between meals you want to feel slightly hungry but not so much that you are ravenous. You want to feel hungry but not so much that you can't ignore it. If you allow yourself to get so hungry that you just can't stop thinking of food, you will binge. What you dont' want is to get in a cycle of eating fewer calories one day because you pigged out the night before. That's just not healthy. And it could lead to binging and purging.
The other thing you really need to do is keep a running average of daily calories consumed in the last 7 days. The truth is, if you stay below your calorie limit all week but then on the weekend have a piece of birthday cake, your weekly average shouldnt really change that much. Everyone knows that one piece of cake isn't going to ruin your diet. What will ruin a diet and put weight on is by consistently eating more than your body can use. I find that when I only look at that day's calorie totals and it's over by a hundred calories, I get frustrated and start feeling like a failure. But if I add that day's calories into the weekly average, I don't feel bad at all because an occasional splurge wont really change the average much (unless you are doing it several days per week).
I've lost over 25lbs three different times in the last 20 years- once after college and then after my first 2 babies. I did it by only lowering my calories a little bit, taking it slowly and exercising. Losing it slowly is the only way to make sure you don't gain it back. I found that after a few months, you start to recognize after meals when your stomach is satiated and you've eaten the right size meal. At that point, you really don't even need to count calories anymore. You get used to eating the amount your body needs to function because you've been eating just under that amount for months. After a few months of counting calories, you also start to recognize when you've put too much food on your plate because after a few months you get used to reduced portion sizes. And you get used to eating healthier and I noticed my tastes changed. I didnt' crave the same things I did before I started counting calories.
Anyway, that has been my experience. I started counting calories about a month ago and I've lost 8 pounds. I'm a little hungry right now but it's not so bad that I can't ignore it. I really think that's key. I'm hoping to lose 20 lbs by October, slowly but surely.
"The so-called right to abortion has portrayed the greatest of gifts- a child- as a competitor, an intrusion, an inconvenience." ~ St. Mother Teresa of Calcutta
"It is not 'progressive' to try to resolve problems by eliminating a human life." ~ Pope Francis