DO NOT EAT BACK EXERCISE CALORIES!!!!!

I'm not sure why the OP is yelling at us.

If you aim for 1200 calories a day, do a half hour of moderate cardio exercise, burn 200 calories, and eat them back, that's THE SAME as eating 1400 calories and not eating calories back.

It's the same math. It all depends on when you add the deficit and when you add the activity level. The dietitian is taking into consideration what you'll burn through exercise before you do it. MFP just waits until you have done it.

The only difference is that if you hit snooze one too many times, or get home from work too late, and don't do any exercise, you'll still lose at the same rate following MFP's calculations.

I just want to explain a couple of things about training for doctors, dietitians, and the basis for standard recommendations. Typically speaking, doctors do not have any education on exercise and nutrition. At most they may have taken a single basic nutrition class. Dietitians coursework focuses on the average person (IE: sedentary) with various metabolic diseases. They are not typically given education in exercise or how to fuel for it. The average client that either doctors or dietitians work with are sick, sedentary people who need to lose weight. For this type of patient, there is a standard recommendation so that it is easier on doctors and dietitians to work with large numbers of people. Doctors are usually the ones who stick to the 1200 or 1500 calorie recommendations because they haven't been taught how to calculate individual calorie needs. Dietitians have those formulas and can determine individual calorie needs which is why the OP's dietitian said 1400 instead of a standard 1200 calories. Unfortunately, the formula they are taught doesn't usually take into consideration any form of exercise because their standard client is sedentary or in some cases completely bed ridden. They don't need to know how exercise effects calories because they don't usually work with people who exercise. There are specialty courses that can be taken to expand on the knowledge of dietitians into more of a sports nutrition scope of practice so that they can handle the needs of exercising clients or athletes. Unless your doctor or dietitian has taken coursework in sports nutrition, they will say not to eat exercise calories because they are sticking to the recommendations and formulas they know, not realizing the effects of exercise on calorie needs. Sports nutritionists are taught that the 500, 1000, etc. calorie deficits aren't correct for most people who exercise because of having to fuel the activity. We're taught to eat a minimum of 80% of the energy expended, including exercise, so that the body will want to maintain it's muscle mass and release fat stores.

So, while I applaud you for getting advise from a professional, I'd recommend asking the professional you choose about their nutrition and exercise education. If they haven't taken some course work in exercise physiology or sports nutrition, they need to step back and work with the clients they are trained to work with and leave the exercisers to those of us who specialize in their specific needs. Each individual should base their choice of professional on their individual needs. If you aren't going to exercise, then by all means a standard dietitian is the way to go. But if you are going to focus on diet AND exercise, please find a professional in your area that can meet your needs.

I just want to explain a couple of things about training for doctors, dietitians, and the basis for standard recommendations. Typically speaking, doctors do not have any education on exercise and nutrition. At most they may have taken a single basic nutrition class. Dietitians coursework focuses on the average person (IE: sedentary) with various metabolic diseases. They are not typically given education in exercise or how to fuel for it. The average client that either doctors or dietitians work with are sick, sedentary people who need to lose weight. For this type of patient, there is a standard recommendation so that it is easier on doctors and dietitians to work with large numbers of people. Doctors are usually the ones who stick to the 1200 or 1500 calorie recommendations because they haven't been taught how to calculate individual calorie needs. Dietitians have those formulas and can determine individual calorie needs which is why the OP's dietitian said 1400 instead of a standard 1200 calories. Unfortunately, the formula they are taught doesn't usually take into consideration any form of exercise because their standard client is sedentary or in some cases completely bed ridden. They don't need to know how exercise effects calories because they don't usually work with people who exercise. There are specialty courses that can be taken to expand on the knowledge of dietitians into more of a sports nutrition scope of practice so that they can handle the needs of exercising clients or athletes. Unless your doctor or dietitian has taken coursework in sports nutrition, they will say not to eat exercise calories because they are sticking to the recommendations and formulas they know, not realizing the effects of exercise on calorie needs. Sports nutritionists are taught that the 500, 1000, etc. calorie deficits aren't correct for most people who exercise because of having to fuel the activity. We're taught to eat a minimum of 80% of the energy expended, including exercise, so that the body will want to maintain it's muscle mass and release fat stores.

So, while I applaud you for getting advise from a professional, I'd recommend asking the professional you choose about their nutrition and exercise education. If they haven't taken some course work in exercise physiology or sports nutrition, they need to step back and work with the clients they are trained to work with and leave the exercisers to those of us who specialize in their specific needs. Each individual should base their choice of professional on their individual needs. If you aren't going to exercise, then by all means a standard dietitian is the way to go. But if you are going to focus on diet AND exercise, please find a professional in your area that can meet your needs.