Hashimoto hypo thyroid & body recomp

Are you taking levothyroxine or similar? This is a condition that has to be treated with meds, you can't fix it with diet and exercise.

Just asking as I didn't see your mention of medication.

I've had the same condition for over thirty years, properly medicated and monitored, and I was able to lose 80 pounds 15 years ago with a reasonable amount of calorie restriction and moderate exercise and I've kept it off. I lost most of my weight at age 54 (female, 5'8") and 1800ish calories (gross calorie intake, including exercise expenditure calories.)

The condition itself is easily treated, and even if your meds are off a little it isn't going to stop weight loss. The calorie difference is negligible, like a hundred calories a day even if you're unmedicated. Heck, I make that number of calories in food logging mistakes every day, I'm sure, and I've been logging food diligently for years. You do have to be monitored with blood tests on a regular basis.

Have you been logging food? Logging everything? Making your own meals? Logging even big eating days?

Your weight lifting could be masking some of it. Recomp, water weight, etc...but you should be losing if you are in fact eating at 1800 consistently. Are you of average height?

I'm going to tag Ann here, she has the myfitnesspal hypo links. Thanks @AnnPT77

I think Riverside is asking me to provide this (very good) link from the Most Helpful Posts area of the Health and Weight Loss topic here in the Community:

https://community.myfitnesspal.com/en/discussion/10767046/hypothyroidism-and-weight-management

It was written by a scientist in the field, himself hypothyroid, who lost weight by calorie counting. It's solid scientific information, a needed counterweight to much of the nonsense it's easy to find on the web.

I've also been hypothyroid for over 20 years, properly medicated (levothyroxine at 175mcg now). I was overweight to obese for a dozen years while training hard, even competing athletically (not always unsuccessfully. I was eating mostly healthy food - had been vegetarian since 1974 (not a typo). I stayed fat, fairly constant weight.

I can readily believe that you're having difficulty losing weight. Nearly everyone does at one point or another. If your doctor hasn't asked for a full thyroid panel (not just TSH) in a while, ask for that.

But, sadly, I'd pretty much guarantee that hypothyroidism isn't why you're not losing weight. At most, even if untreated, you might require somewhat fewer calories than someone of similar characteristics who isn't hypothyroid.

For a long time, I thought I had a "slow metabolism" because I stayed fat despite regular serious exercise and healthy eating. Maybe the reason was my thyroid, maybe it was age (then late 50s), maybe it was menopause. But once I got my calorie needs figured out, and stuck to a number slightly lower than I needed to maintain weight, I lost fat, and kept losing it until I decided to go back up to personal maintenance calories.

I'm 5'5", 132-point-something pounds this morning, female, age 67, severely hypothyroid, and will lose weight ultra-slowly on 1850 plus all carefully-estimated exercise calories. That's high for my demographic, because - I believe - I do have somewhat higher muscle mass than average for my demographic, as you also indicate you have.

Maybe you do need fewer calories than you're eating, because people vary. If your logging tells you you're holding steady at 1800 calories, drop to 1500, keeping everything else constant. You should start losing about half a pound a week at that level. Losing slowly can be a good plan to retain current muscle while losing fat, maybe even gain a little muscle mass very slowly.

Gaining muscle mass is slow. Recomp is a slower way to do it (vs. bulk/cut). Recomp on a calorie deficit will be even slower than that, if it can even happen. (If you're extremely overweight, odds are a little better.)

Get enough protein and good overall nutrition, follow a good progressive strength training program, and reduce your calorie intake. Stay at the new level consistently for a couple of months, then assess progress on average over that time span. If you feel up to it, let us know how it works out?

I'm wishing you success, sincerely!