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Writer's pictureCheryl Hoover

Tamoxifen and Weight Gain - by Cheryl Hoover


Cheryl Hoover is a pharmacist and breast cancer survivor who writes about how food can contribute to health.

The role of tamoxifen in breast cancer treatment


Tamoxifen has been used to treat breast cancer for over 30 years. It is a “SERM” (selective estrogen receptor modulator), that works by attaching to the estrogen receptors in breast cells so that estrogen cannot bind to them. Tamoxifen slows the growth and reproduction of estrogen-sensitive cancer cells. At the same time, it instantly and abruptly puts females into menopause which can be startling to say the least.


There can be an associated weight gain in some women on Tamoxifen but is it the drug, the instant menopause caused by the drug, fluid retention caused by the drug, decreased mobility during treatment, or a combination of any or all of the above that can cause the weight gain?


Weight gain and tamoxifen: unraveling the factors


For the sake of this blog, the answer really does not matter. What does matter is that this weight gain is troublesome and real if it happens to you.

When you get a cancer diagnosis so many things are out of your control. So, let’s talk about something that is in your control- How You Fuel Your Body. I like to tell people to begin to think of eating as an opportunity to nourish your body and not just feed it. Every meal you eat is a chance to lean into this opportunity by eating nourishing food and in my opinion the best way to take control back and begin to tackle that pesky weight gain.


life after cancer changes

Taking Control of Your Health Through Nutrition


So what does properly fueling your body really look like? It is simple really but definitely not how we typically eat in our country. The products that are marketed to us are convenience foods, ultra processed foods, and manmade foods. Rarely do you see any advertisement for natural real foods but that is exactly what we should be eating. These real foods are important not only to fuel our body properly for our best health and healing, but they also will fill us up with natural fiber and therefore we are less likely to over consume empty calories.

A “calorie is not a calorie” for many reasons but in this case because it matters if you feel full after eating those calories or not. Food rich in natural fiber will tell your body that it is full and it will keep you full longer than empty calories. Okinawa, Japan is one of the Blue Zones where a large percentage of their population live very healthy lives well into their nineties. In addition to eating mostly plants, they also have a wonderful tradition of only eating until they are 80% full.


What an easy way to take control of your health, and Michael Pollan says it best when he says, “ Eat Food, Not Too Much, Mostly Plants.”


I agree with his simple statement and propose that this is a good place to start if you are struggling with weight gain from Tamoxifen or the resulting menopause that it has abruptly put you in. If your diet looks very different from this, start slow and take a few steps in this direction and start listening to your body. It will tell you how it feels and you will see the difference.


Stay in touch.


About Cheryl Hoover


Cheryl Hoover is a breast cancer survivor and a nutrition coach at The After Cancer. Her mission is to encourage patients to embrace the opportunity they have to nourish their body for their best health and healing.

Cheryl Hoover


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