TDEE vs. MFP Calc?

MFP does not include calories for exercise. TDEE does. MFP gives you a lower target calorie goal, with the expectation that you will eat extra calories to fuel your workouts.

So, either go with MFP calculations for NET calories, 1410 + calories earned through exercise.

Or, set your own goal as TDEE - 20% and do not eat any extra calories for exercise.

TDEE = Total Daily Energy Expenditure - TDEE is the amount of energy (in calories) that your body is using each day. (BMR plus the additional energy used in your daily activities including exercise.) To lose weight, you generally want to eat under your TDEE, but over your BMR. To gain weight, eat over your TDEE. (See calculators to figure out good targets within that range.)

BMR = Basal Metabolic Rate - BMR is the minimum energy that your body needs to sustain itself at rest. This amount, measured in calories, would be necessary for basic functions like breathing, heart beats, renewing tissue, etc. Eat above your BMR except under very special conditions and with medical supervision.

Since MFP doesn't have a TDEE calculator, I think you may be getting the two numbers confused.

Headaches can be caused by low blood sugar. I used to get them in the early afternoon, if I hadn't eaten by then. You may be right that you aren't eating enough or maybe you need to eat at different times. Headaches can also be caused by other changes in your diet. Are you eating things you didn't eat before? You may be mildly allergic or having a reaction to them. Many "diet" foods have artificial sweeteners or MSG; both of which can trigger headaches for many people. Or it could be something you dropped from your diet. Rapid drops in caffeine intake can cause headaches; they'll go away after a few days or you can slowly have less and less caffeine to lower the level your body is used to having. If you're tracking what you eat, it may help to track when you have headaches in the notes, then look for patterns.

Congratulations on the weight loss so far. Good luck figuring out what works best for you long-term!

Edited to add this link to other terms and the links to calculators: http://www.myfitnesspal.com/blog/Robin_Bin/view/mfp-terms-introductory-274185

Also, the TDEE-% or MFP calculation with deficit based on your goals and then adding back calories for exercise as you record it (many other sites add calories based on what you say you will be doing) are both good ways to calculate an initial target. Don't go under 1,200/day without medical supervision. Try to eat healthier than you were before. Either method of calculation gives you a starting calorie target and then you can adjust after you see how well it works for you. (Try it at least 1 month first, because there may be some initial changes based on water weight, time of the month or other temporary factors.) Since you're on the MFP site, I recommend starting with the MFP guidelines based on your entries here. As you learn more and see how your body reacts, you may switch plans or mix and match. Oh, and whichever plan you use, make sure you eat healthy, including fiber and drink plenty.