I am getting discouraged! I haven't lost a single pound!

I can't view your diary but based on what you're saying, you're eating too few calories per day and you're putting your body in 'starvation mode' which slows up your metabolism and makes you hold on to stored fat. You need to increase your caloric intake to at least 1200 calories per day.

A few questions:

How long have you been at this?
Are you logging everything you eat?
What is your CW?
How much are you trying to lose a week?

The answers could help people answer your question better.

Men arn't supposed to dip below 1200 cals ..not sure about women tho. Find out what your Basal metabolic rate is or BMR..which basically is a number of cals you burn a day just by living and breathing...after all your body needs energy just to survive. Factor in what you eat and the difference between the two should be 500 or greater..any exercise needs to be factored in as well..but 800 cals a day does seem low and counter productive

800 to 900 calories are less than what my 36 pound 5 year old eats in a day.

Simply put you are eating too few calories.

I just started a week ago, so I know it hasn't been long. The only days I didn't log were Saturday and Sunday. We had a wedding and went out to eat twice on Sunday. My current weight is 165 and I want to be down to 120. I really want to lose about 2-3lbs a week.

Seriously? It's been one week and you ate out twice and went to a wedding. I'm sure you had a bit more than 800-900 calories a day. Get serious about dieting and eating less.

First, that is a lot of weight to loose per week. And only being at it a week, you need to give yourself more time.
Second, you do need to eat more calories. I once ate less than a thousand calories and this program yelled at me telling me that it would slow down my metabolism if I kept at it. I don't eat less than 1200 now.
Third, If you are walking and exercising, you could be putting on muscle weight first, then you will see the weight drop after that. the first thing you will notice is a change in your body shape.

I hope this helps, and good luck! It is a slow process, but it works, I have lost 6 pounds now in about 5 weeks. It takes time, but it is worth it.

It has only been a week and you may want to increase your calories a little. If your workouts aren't that hard then you won't see a dramatic lose in weight. Keep at it and losing a 1lb every few weeks isn't bad either. Or increase your workouts and what you are doing. Maybe a bike ride or running...Just a suggestion!

Good luck!

I just started a week ago, so I know it hasn't been long. The only days I didn't log were Saturday and Sunday. We had a wedding and went out to eat twice on Sunday. My current weight is 165 and I want to be down to 120. I really want to lose about 2-3lbs a week.

Seriously? It's been one week and you ate out twice and went to a wedding. I'm sure you had a bit more than 800-900 calories a day. Get serious about dieting and eating less.

And realize that you are NOT likely to be losing 2 to 3 pounds a week....

You also have to get realistic with your goals.

READ THIS:

http://www.myfitnesspal.com/topics/show/833026-important-posts-to-read

800-900 isn't going to be sustainable in the long run, and doesn't leave you any room to move if you ever get to the point of needing to adjust your calories again.

Start with the HIGHEST amount you can lose weight on and work down from there; do not start at the very bottom. Your first couple of weeks should be spent logging 100% HONESTLY what you NORMALLY eat so you can see the problem.

I just started a week ago, so I know it hasn't been long. The only days I didn't log were Saturday and Sunday. We had a wedding and went out to eat twice on Sunday. My current weight is 165 and I want to be down to 120. I really want to lose about 2-3lbs a week.

1st: You won't be able to lose 2-3lbs a week. Sorry, it just isn't possible. You don't have much to lose - set your MFP settings to losing 1lb a week and eat back the calories you burned in exercise. You aren't eating enough. 800-900 calories a day isn't enough for a child, let alone you.
2nd: Patience. It's only been a week. It took me 2 full years to lose 45 pounds. Slow and steady teaches you how to keep it off. Develop new habits so that you'll never have to do this again. I've been at this long enough to know that eating really low and exercising like a fiend won't make the weight come off any faster.
3rd: Great job changing the way you eat. Reducing soda, refined sugars and processed foods are a great start - but I can tell you from experience NO ONE has the willpower to never eat/drink something like that EVER again. I follow the 80/20 rule, 80% of the time I eat well, 20% I eat things I shouldn't. Keep the portions small, if it fits in your daily calories and isn't affecting your macros, eat it and don't feel bad about it.

I just started a week ago, so I know it hasn't been long. The only days I didn't log were Saturday and Sunday. We had a wedding and went out to eat twice on Sunday. My current weight is 165 and I want to be down to 120. I really want to lose about 2-3lbs a week.

A week isn't long enough to be sure of results really. Your body isn't going to go into starvation mode after three or four days of eating 800 calories. I would be more concerned about the days that you didn't log. Restaurant food can be very high in calories and sodium. You could have made up for your calorie deficit eating out, so you maintained. Or you could have just gotten way too much sodium so your body is hanging onto water weight.

I would suggest eating the number of calories that MFP suggest for you, every day, but being careful about weighing and measuring stuff, and tracking as best you can when you go to a restaurant.

I would recommend a goal of 1 lb loss a week - that would be a deficit of 500 calories a day. The easiest way is to use the MFP goal tool to set it, then be sure to eat back your exercise calories. Note that you may want to eat back only 75% of the calories rather than all of them to account for error, and/or look into a getting Heart Rate Monitor or FitBit to get more accurate calorie counts from your activities.

Get a kitchen scale and weigh your food as much as possible. If you cannot weigh it, measure it (my wife always gets annoyed that I either weigh or measure everything she cooks...) If you ever have to estimate, it is better to guess high (especially for restaurant food). If you go out to eat, don't plan eat more than 1/2 of your meal (although if you have the calorie count you can decide what fits into your daily goal.

Hide the bathroom scale for at least a month and concentrate on a balanced diet and exercise. After that month, try not to weigh yourself more than weekly, and always at the same time of day (morning before eating is generally best). Don't let weight ups and downs discourage you either.

Consider taking your measurements (neck, chest, waist, hips, etc.) once a month to gauge fitness in more than one way... even if you don't lose lbs fast, you can lose inches.

Good luck on your journey.