who really knows their tdee? and who just thinks they do?

As an exercise physiology student, I used the metabolic cart at my university to measure my RMR and also my VO2 while exercising and compared those numbers to the various formulas for determining BMR, RMR (EER), and TDEE. I then picked the formula that gave me the closest estimate to my measured readings to use for my clients, and luckily for me it was also the simplest for doing the math. You can see how I figure it for my clients on my blog at: http://www.myfitnesspal.com/blog/TrainingWithTonya

---

16 years Certified Personal Trainer and Group Exercise Instructor
9 years Certified Sports Nutritionist
Bachelors in Exercise Physiology with a Minor in Nutritional Science
ACSM Certified Clinical Exercise Specialist
NSCA Certified Strength and Conditioning Specialist

They are all ESTIMATES. You have to adjust based on real world changes. All the more reason to stop counting/eating back exercise calories and just stick with a moderate absolute deficit.

I haven't got a clue what my TDEE is, all I do know is that just because figure **** suits one female, 51, sedentary job, who runs three times per week, does not necessarily mean that exact same figure will suit me.

I stick to 1200 calories per day, go into my exercise calories by 50 or 100 and leave the rest alone. 1.2lbs to go to my goal, my method seems to be working for me, but for somebody else, it may not.

I got tested at the gym to determine my VO2max and TDEE. I know they're not laser-accurate, but they're better than guessing completely.

http://scoobysworkshop.com/calorie-calculator/ <---- this is how I figured out mine. I set mine at sedentary, then I set my mfp to the TDEE # on MFP didn't calculate any exercise - eat back exercise calories on the days I do exercise (some not all)

All of the online calculators for BMR and TDEE are based on formulas that ESTIMATE the values. They are APPROXIMATIONS, nothing more. The only way to know exactly what your TDEE is every day would be to constantly measure it. This would be unrealistic since you would need to live in a lab to do so. The good news is, you don't need to know exactly what your TDEE is, you just have to get fairly close.

Here's what has been working for me: I started by using the value that the online calculator gave me (1800 calories) as a daily base. I then add in the calories I burn doing cardio (bicycling) every day. Since the cardio numbers vary so much (600 on easy days to near 2000 on race days) I add those daily as a discrete amount. Then, I make sure I log everything I eat, and I mean everything. If you don't you're only making it more difficult for yourself.

After doing this for a week or two, you can compare the numbers (calories consumed vs. calories burned) and see where you are. Are you still losing weight? Is it at the rate you expect? If not, your estimation for TDEE may be high. For me, it was too low. I had to increase it so that I could keep up with the amount of cardio I do. Good luck!

I'm wondering whether I've been way under on my TDEE and my BMR. Using the MFP calculators and leaving my settings at sedentary, I have a BMR of 1,750. MFP estimates that I burn 2,130 every day from normal activities. It is recommended that I eat about 1,200 calories a day to have a loss of 2 lbs. a week.

Here's the thing: For the past three weeks, I have been over on my calories -- last week I was almost 2,000 over for the week, roughly 250-300 a day. Yet I still lost 3 lbs. in each of the past three weeks. I'm thinking I maybe set my activity too low, but I do eat back my exercise calories -- especially if I deliberately go to the Y to walk the track or treadmill.

Today, I'm roughly 100 calories over my maintenance. Oh well, I'll have to get some exercise in this week.