Weight Gain with Aromatase Inhibitor

MarieG2023

Hello. For breast cancer survivors that have/are using an aromatase inhibitor. Did you experience a gradual weight gain? How did you handle it? I'm very blessed to be a survivor, but I'm noticing an increase in weight despite my calorie counting and exercising (I work our 5-6 days a week). Any input is appreciated!

AnnPT77

MarieG2023 wrote: »

Hello. For breast cancer survivors that have/are using an aromatase inhibitor. Did you experience a gradual weight gain? How did you handle it? I'm very blessed to be a survivor, but I'm noticing an increase in weight despite my calorie counting and exercising (I work our 5-6 days a week). Any input is appreciated!

I think this won't be helpful, but . . .

I did 5 years of Arimidex.

After my basic cancer treatment for stage III breast cancer (surgery, chemo, radiation), which put me into menopause at age 44-45, I took Tamoxifen (not an aromatase inhibitor) for 2.5 years, then Arimidex (which is an aromatase inhibitor) for 5 years. Also, a few months after finishing radiation, I was diagnosed as severely hypothyroid. Getting that properly under control took several months.

Nonetheless, I did not notice a gradual weight gain. I'm not sure why, honestly.

Some things that may've mattered, not sure: After base treatment I started focusing on eating lots of veggies/fruits (my job's wellness program had a "Colorful Choices" education program that helped). I'm sure that improved my overall nutrition, and (speculatively) may've reduced systemic inflammation. Around the same time, I also became very active (including becoming a competing athlete, training 6 days most weeks). Pre-cancer, I had been quite inactive, sedentary. (These things may've had different effects, for me, than in someone who'd long been eating lots of veggies/fruits, long been very active - no way to know.)

Regardless, the net effect was that my weight stayed reasonably stable, at around the line into class 1 obesity, for over a decade. I did lose a couple of pants sizes without much weight change, so I probably did achieve some recomposition (gained muscle, lost equivalent-weight fat to stay same body weight).

I'm sure my calorie expenditure had gone up by a few hundred calories most days (from training) vs. pre-treatment, but I don't know whether my calorie intake was the same, higher or lower: I didn't start calorie counting until a decade-plus later.

Other things that can contribute to creeping weight gain from medications are fatigue (perhaps subtle), and water retention. I think for me the gradual ramp-up in activity, plus resulting fitness improvement, might have cancelled out any fatigue effects along the way - no way to know.

I also know that some people experience joint or muscle pain with any of the hormonal therapies for breast cancer, and that can reduce activity level (in daily life) or reduce exercise intensity, again perhaps subtly.

I've been off Arimidex for a very long time, now - don't recall for sure, probably finished in around 2010. I lost weight pretty straightforwardly back in 2015-16 (age 59-60), 50+ pounds in a little under a year, down to a healthy weight, and have been at a healthy weight since, now age 66. During weight loss, and continuing now, it became obvious that I burn more calories (seemingly, even before exercise is factored in) than MFP's estimates predict. I don't really know why, though I suspect I have relatively more muscle mass than most women my age/size. I do "credit" Arimidex with causing me osteopenia then osteoporosis, since there doesn't seem to be lots of it in my family.

Like I said, I think this is not helpful to you, but it is one Arimidex experience.

One thing I'd ask: How's your protein intake? Sub-ideal protein can contribute very slightly to gradual weight gain, over a long time period, in a couple of minor ways.

II hope you're able to figure out something that works for you!