Mary is losing fat. There is nothing wrong with her.

because she's gaining muscle, which not only is replacing some of the fat weight, it weighs more than the same amount of fat would. If you're lifting it makes more sense to judge by your measurements than it does by the scale because you're going to be gaining muscle weight.

She ignores her relativity to gravity and goes off of bodyfat, clothing fit, measurements, strength, and endurance... takes a sledgehammer to scale.

Then how can she get at her desired weight if she is gaining muscle at the same time.

By stopping strength training, eating at a huge deficit and losing muscle. Is this really what Mary wants?

Who cares what the scale says if Mary is losing body fat??

Scale weight is an arbitrary number. It cannot take into account LBM, water, etc etc on any given day. It will always fluctuate.

So I no longer understand this hypothetical scenario.

Once again, if Mary (for whatever unreasonable psychological reasons are at play) HAS to be at a particular number on the scale, she should eat at a large deficit and stop bothering to strength train or maintain muscle. That would be the easiest way to "control" the number on the scale without having to deal with muscle mass and fluid retention from lifting. Not the healthiest, though.

I don't want to play anymore. Unless you're trying to teach people what NOT to do, in a round-about way. But I think there are better ways to get this message across.

Then how can she get at her desired weight if she is gaining muscle at the same time.

You could gain perhaps, if male, almost a lb a month of LBM if eating at maintenance. Not muscle mind you, LBM, which of course includes some muscle, and everything else that is not fat.

http://www.myfitnesspal.com/topics/show/778012-potential-muscle-gain-lifting-and-metabolism-improvement

But good news - LBM causes an increase it metabolism too, even if just stored water, because it takes energy for the body to mess around with the water. Well, not in your gut though.

So, the TDEE estimate is likely off, or since it is based on the BMR, that is likely off.

If you want to maintain current LBM and start dropping the fat weight without just trading it, you need more deficit. Or rather, get your TDEE correct because it's not. Then when you take the deficit, you'll actually be losing.

BMR issue - if you used the Harris BMR estimate and not the Katch BMR based on BF% - that could have been easily inflated by 200-400 calories. Times a multiplier of 1.55 for Moderately Active mary may have selected with that routine, that's 310-620 at TDEE level, and with 15% deficit, still inflated by 264-527 calories.
See that range, even with a deficit taken, the inflated BMR and TDEE has left the eating goal ABOVE her better estimated TDEE.

That means eating at TDEE, and doing the body a great service to gain LBM from great workouts while burning fat, but terrible for losing more fat that could be had.

TDEE issue - was Moderately Active selected on basis of working out 5 days a week? Is 60 min of walking equal to 30 min of HIIT equal to 45 min of heavy lifting? No way. Lifting actually requires less energy during the workout, but more fat is burned during the recovery. I doubt the vast majority on MFP need to replenish fat stores. Just carb stores. HIIT is the same thing, despite high HR, burn is not as much because it's more like lifting, anaerobic efforts.

Activity issues - lifting 3 times and 2 days doing HIIT? I sure hope Mary isn't doing HIIT with the same muscle trying to repair the day after lifting heavy. Actually, do that enough times and you aren't doing either as well as you could. If the muscle can't repair and get stronger from rest, and HIIT just used it again, you killed the repair process. And if lifting the day after HIIT, same thing, killing the repair if same muscles used, and you can't really do the lift as well as you could rested.
That's just a whole lot un-useful stress on the body, where it's can't even really get stronger from the workouts. It'll feel like you are pushing yourself sure, but not nearly as much as you could if done properly.
All that stress, even if eating at maintenance, is going to cause bad effects.

So those are the 3 things I'm seeing more and more discover as they continue on this journey of eating correctly for their level of activity.

And I doubt to that bodyfat% estimate. If done with measurements, I hope something like the following calc's with many measurements and avg.

http://www.gymgoal.com/dtools.html

I would question that Mary actually has 21% bodyfat at 5'4" and 205 pounds. Unless Mary has an unbelievable amount of muscle - like body builder amount. I would also like to see how her measurements have changed.

My initial thoughts exactly. Very unlikely Mary has gained that much muscle in a short space of time while eating at a deficit.

If she started at 210 lbs and 30% BF then she was carrying 63lb of fat and 147lb LBM. Then at 205lbs and 21% BF she was carrying 43.05lb fat and 161.95 LBM. Therefore she's lost 19.95 lbs fat and gained 14.95 lbs of LBM in just a few months. Obviously some of this will be water etc but it seems highly unlikely.

because mary desires to be at this particular number. Mary should be able to achieve her goal so hoe is mary going to get there. Again this is a scenario not me at all. I'm just interested in the response my personal opinion if she desires this weight she needs to decrease her calories still do the strength training make sure her protein intake is intake. Cardio can stay the same.

I don't understand why it's so important to be a specific number that merely represents Mary's relationship with gravity. But to play along, in order to lose weight she may as well quit exercising altogether and eat at a large deficit. While continuing to strength training scale weight is unlikely to drop drastically. But she should remember this will result in decreased LBM as well as fat loss. Seems a strange goal to me.

Perhaps she should try the 'catabolic diet' I saw posted on here this week - eating mostly fruit and veg, avoiding carbs and protein.