The EM2WL starter kit suggest doing two HIIT training sessions for 20-30 minutes twice per week alternated with strength training sessions. And you may also try to increase your daily everyday movement. Like Parking further away, taking the stairs instead of the elevator. Increasing your NEAT (non exercise activity thermogenesis) will aid in your fat/weight loss. Neat calories just like exercise calories are in your TDEE!

I know I just messaged you...but I wanted to add something since I had time to read your post! Adding in cardio won't cause you to lose weight as long as you increase your TDEE to match your increase in activity. Weight loss comes from burning more calories than you take in. So if you burn more by adding in cardio, eat more so you don't gain. Or don't eat all of those calories back to create a deficit. HIIT is not a requirement, it just helps with fat burning and cardiovascular health. I prefer an hour long Spinning class which includes some HIIT and Tabatas instead of two HIIT sessions. You just have to find what works for you and your body!

Example.

TDEE with lifting only workout - 2000
2000 - 15% = 1700
300 cal deficit

TDEE with lifting and cardio workouts - 2200
2200 - 15% = 1870
330 cal deficit

You do increase your TDEE 200 if you add exercise.
Which makes your deficit 30 bigger, and you get to eat 170 more.
Shoot - do more lifting and increase your TDEE too.

That's actually the best bet if you enjoy doing it and don't just feel an overwhelming desire to do cardio.

I agree with many other trainers you'll find out there, if you want to do lifting for all the positive benefits it gives you, make it your focus, and don't do anything that takes away from best possible results.

Some things are obvious, don't get drunk and then try to go and lift. Don't run for 2 hrs and then try to go do squats and deadlifts. Don't swim hard for an hour and then try to do upper body.

And this is nothing new, truth been around for awhile. But a lot of stuff lately has been pushing people to jump on bandwagons based on recent studies, to do all the best fat burning type things together, thinking that is better. These same sources also jumped on the cardio fat-burning HR zone when that was a fad years ago, now the swing is to the other extreme.

You get the best benefit from lifting when you progressively overload the muscles, forcing your body to repair and become stronger, if starting out and extra fat, even growing some muscle. Reasonable deficit enhances that, obviously eating in surplus really does.

But you cannot, and especially not in a deficit, progressively overload tired muscles. If your muscles are tired because of what you did the day before, you cannot lift as strong, and increase weights as fast, ect.
In other words, you are not putting the load on them for max benefit of your lifting.
You are not getting the most from your lifting workout.

You cannot, especially in a deficit eating, fully recover muscles from lifting in less than 24 hrs, such that you can put another heavy load on the same muscles. If you want the best recovery and repair to get the max benefit from your lifting, you need to allow the muscles to rest.
Repair and rebuilding requires rest, nothing happens during the exercise except tear down.

Those 2 facts combined mean that any meaningful lifting program of 3 x weekly has no place to stick a HIIT routine.
Now, you could do 2 x upper and 2 x lower a week, and get one routine in there, if you just loved the cardio and needed to do some and had little time.

But lets be honest why HIIT is recommended. Because compared to straight cardio, it burns more fat during recovery.
Why? Because if done correctly (which frankly it rarely is) it can have a very similar, though not as good, response from the body as lifting does.
It's the cardio-only version of lifting.

But if you don't need it, then do upper 3 x and lower 3 x weekly, and just get full benefit from the lifting, don't screw it up.

The sites that recommend HIIT and lifting together will either give a routine that is correct, or will caveat the fact it will impact your lifting if done wrong.

And don't think of reset as any different than deficit, except in amount to eat.
But since it takes energy to do best repair from exercise, you do take longer to repair in deficit. And it is harder to make progress in deficit.
But the focus is weight loss, not performance improvement.
You can push for improvement obviously, and merely accept it can't be the same as when eating at maintenance or above.

Your increased NEAT is another great fat burner actually. The elevated metabolism from lifting, and slightly less from HIIT, is more than equaled by your list of increased daily activity.

But keep doing the lifting, and when you reach point it's not hard, time to increase the weights.
I'm betting it won't take long at all.

And for your joints sake, don't worry about the cardio, your lifting right now is improving your aerobic condition too. Higher reps than higher weight.

Oh, why only 200 cal deficit? That could accidentally be wiped out with some bad measurements or estimates in food logging.

WOWZERS Thanks Heybales this was awesome!!! Sticking to my 3 x a week and doing upper and lower body those days....I am doing a 200 deficit only for 2 weeks per Lucia. Then I will likely come down more. I was eating above my TDEE remember for 4 weeks by mistake, then back down to my TDEE for 2 weeks making my reset 12 weeks. Now I will eat in deficit 200 cals for 2 weeks. I am actually eating in a 267 cal deficit right now (2467TDEE to 2200 cut). In 2 weeks I will drop down another 103 cals. Doing a 15% cut. If I am to understand when I see losses I should stop the deficit. I have noticed I lost 2 lbs this week, where when I was at TDEE I maintained well. Any suggestions are appreciated. I know I do this for 6 weeks and then re-evaluate TDEE and eat TDEE 2 weeks and then back to cut and on and on.

When you see a loss you are supposed to stop the deficit?