Well, OBVIOUSLY, BOTH! ;-)
I'm not 100% sure how you can get from where you are to where you want to be, though.
So, let's talk about ME, because I can make points without sounding nasty.
Start point: Born male, so far as we know - no genetic checks.
5'9" (almost)
240#, with weight varying from 180 - 240 a few times over the last 10+ years, call it.
Diet doesn't do squat for me so far. I eat like a bird, I lose nothing. I eat like a pig, I MIGHT gain a bit.
So for me, it's a question of (in order), EXERCISE, then, Good Diet.
I've been looking at things like Banting (ketogenic diet), high protein/low carb (Atkins being poster child, Paleo close second). But again, up until VERY recently - if I ate a lot, I didn't gain much (on a per-week basis); if I starved myself... Well, ate a bit less? No losses.
The only way I've been able to reliably lose weight and keep weight off is to be active - which is a MAJOR accomplishment for an IT specialist. ;-)
You sound like you're doing a lot to make the exercise part of the equation part of life. So you got the tough part (for me) down... You could tweak it by adding High Intensity Interval Training, or just High Intensity Training for strength training - be cautious what and how, but build the muscles you need (I'm guessing, gluteals especially gluteus medius; quads, since many women are quad-dominant; lower back, mostly erector spinae, IIRC; and some ab work, meant to cause toning, not mass gains. And nothing for arms, mostly - they'll probably get all you'd want from changing weights. ;-) )
For me, I loved weights. LOVE being strong - I was the "wimp" in grade school, so... Yeah, no details, just - I like being physically strong. Not BIG - just STRONG.
But I blew out BOTH shoulders about two months ago - not sure how, if it's rotator cuff or deltoids or some combination. But it means essentially, NO arm activities with weights. So I went to doing some yoga every other day... And I'm down to 221 as of this morning (from 240 two months back). No muscle atrophy I can see; 0.5% body fat reduction... And doing a high-fat approach, which is nice and filling. Bulletproof coffee (Use salted butter, and don't bother with the brand-name beans and such) makes for a great filler...
So, coming back to your questions:
- if you don't want muscles to atrophy, use them.
+ Biking, walking will keep tone
+ Lifting (heavy squats, esp, front squats to emphasize quads; butt exercises to target gluteal group, esp
gluteus medius, to get more of a "hippy" shape; MAYBE a set of deadlifts, depending on your back strength,
and ab/core exercises to pull in the obliques. Use hooks for the deadlifts so your forearms don't grow too
much. Figure high intensity exercises for maybe half an hour? that means heavy where you need to build
size, in sets of 10; and then lighter stuff as needed for balance, toning, weight management.
Can't say enough good stuff about Yoga. Been doing Ashtanga, and one called "yoga for weight loss" (target and Walmart have the disk), which is REALLY good for sweating out the excess, apparently.
diet-wise, EAT MORE / EXERCISE MORE. What has worked best for me is keeping a calorie count and eating count, and ignoring the desire to snack. I get frustrated, I want cookies. They're downstairs, a short elevator trip away...
So, instead, I eat more fat - cheese, for example, or cream or full-fat milk. I track that carefully.... I'm not hungry if I've had enough fat in my diet. Bulletproof coffee, again. Lots of fat, keeps the body burning fat for energy. NO carbs, essentially, and NO grains. That includes cookies, crackers, pasta, rice, and sugars - all of which do bad things to insulin... More insulin = store fat. control insulin = keep body in fat-burning state (low insulin.)
:-)
Also, when you do a strength workout - don't do post-workout nutrition "right." No shake, no sugar. the body will be in a catabolic state (burning muscle). Let it sit there for a little bit. Half an hour or an hour later, have your shake or real food, and keep going from there. And lots of stretching, too. Stretch whatever you were working. :-)
I figure if I can keep that approach up for three weeks out of every month, I should be down in the 190# range by Christmas. :-D And hopefully get down into the 20% BF range, too.
Now, the first time I lost the fat, it took two years, and I remember being on the treadmill thinking I was starting to look good... "Man, I'll look hot when I put on a bra now!" ;-)
Yeah, you know you're Trans when.... ;-)
20 years later, life really got in the way of life, but we just keep going, right? :-)
Good luck, keep a journal, and post back with success! :-)