So this TDEE-20%, does it work?

Yes TDEE method does work. With the tdee method your exercise calories are already including in your daily deficit. Therefore you would not eat back exercise calories. The reason why the daily caloric intake is higher. Unlike the MFP method, exercise calories are not including, therefore you eat back exercise calories.

It averages out to be the same amount usually between the two methods. However with TDEE you eat the same amount everyday.

ETA: For your height and weight....yes that is about right IF you are not working out. If you are exercising your TDEE would be higher than that.

What about calculating the number of calories as sedentary and then using exercise cals from MFP? Sorta like a hybrid?

It works. As long as you eat less than your TDEE and count accurately, you should lose, although you may need to experiment a bit to get your TDEE, as the calculators are just estimates.

You should know that there are two reasons it differs from the MFP recommendation. The first is that it includes exercise calories, whereas MFP expects you to eat back exercise. The difference is much less once you factor that in. The second is that if you ask MFP for a 2 lb loss/week, it will deduct 1000 calories or as close to that as it can without going below 1200. If you deduct 20% from the TDEE of a typical woman, especially one who is not that active, you won't be deducting anywhere near 1000 calories. For example, if your TDEE is 2000 and you deduct 400 for a total of 1600, you are aiming for a loss of just under 1 lb/week. It might end up being higher--IME, more calories can result in bumping up activity and thus overall TDEE--but the weekly goal you are seeking is less than when you ask for 2 lbs/week, the usual reason people get the 1200 recommendation from MFP.

I think TDEE works best when you're consistent AND realistic about your exercise.

If you put a higher activity level into the calculator because you really-totally-definitely plan to get to the gym 5 times a week, and then you don't go more than once or twice, then you're definitely going to be overeating with the TDEE method. Whereas the MFP method will give you the extra calories to eat back on the days you actually do work out, and not on the days you don't.

So yeah. Be realistic, not aspirational.

On the other hand, TDEE, when used correctly, does allow you to eat a more consistent calorie level each day, rather than yo-yoing from low to high based on workouts.

Also, this isn't inherent to the TDEE method, but the calculators most commonly used by people on this forum tend to give you a calorie count based on a 15-20% deficit, which is probably more realistic and healthier than the 1-2 pound/week pace that most people target in the MFP calculator. Sure, I'd *like* to lose 2 pounds per week... but realistically, that ain't gonna happen at my height, weight and size. The TDEE calculator tells me I can probably manage to lose about 0.7-0.8/week on average if I stick with it, so that sets up my expectations for a slower, more sustainable pace.

One thing: Recalculate your TDEE calorie goals after every 5 pounds lost. Since it's calculating deficit as percentage of caloric intake, if you want to keep up a 20% deficit, for instance, then you have to reduce caloric intake as you go along.

Oh cool thanks for clarifying!

Also, the 1200 floor that MFP gives you won't generally amount to 2 pounds per week. If you've input 2 pounds per week, but eating 1200 calories only gives you a ~250/day calorie deficit, then it will tell you that this adds up to more like 0.5 pounds per week.

Sure, you could eat less than that to attempt a 2 pound/week loss, but it probably means that you're a fairly small person, and 2 pounds per week simply isn't realistic given percentage of body weight. But that means that when you 'eat back' your exercise calories, you have to be pretty careful not to overestimate calories burned or underestimate calories consumed, lest you wipe out that pretty small deficit.

by definition it will work. The only problem you may have is accurately predicting your TDEE Practice makes perfect though :-)

I am 5'7" and started here at 245 and have been losing about 1.8 lbs/week on 1500-2300 per day (averaging in the 1800-1900 range).