Weight gain and prescription drugs: a common dilemma

Weight loss and weight loss maintenance are difficult at the best of times. Finding the right balance of exercise, nutrition and sleep isn’t always easy and sticking with it for the long term can be challenging for many.

But what about when you have a medical condition that requires you to take medications that hinder weight loss efforts? Or worse, cause you to gain even more? Sadly, weight gain and prescription drugs often go hand in hand.

weight gain and prescription drugs

A long time personal training client of mine has recently put on a lot of weight, despite following the exercise routine and nutrition plan I’ve created for her.

We’ve had great success in the past; during the first six months of our training relationship she lost 25 pounds, many inches and made incredible gains in the gym. Clearly, her body is capable of responding positively to weight training and clean eating.

What then has changed over the past year and a half?

Turns out that this client is bi-polar (I knew this, but it hadn’t previously been an issue). She had been stable on her medication for many, many years, but suffered a breakdown last year after the death of her father. Her doctors decided to switch meds in an effort to stabilize her. Over the next six months, they slowly increased her Lithium levels and introduced a new anti-psychotic drug, Olanzapine. While her mood gradually improved and she began to returned to her usual self, she also began to re-gain the weight that she’d previously lost (and more).

Initially it was because the Lithium was making her ravenous. She was eating many more calories than required for maintenance but seemed unable to control the cravings and mindless eating. Her doctors introduced Olanzapine, which helped to control her appetite, but still she continued to gain weight.

A little bit of online research revealed that both drugs have well known weight gain effects; effects that appear to over-ride lifestyle approaches to weight loss and weight loss maintenance. Olanzapine in particular, changes the body’s sensitivity to insulin, and over time, can actually lead to the development of Type 2 diabetes.

Talk about frustrating! Either you take the drugs to control a serious medical condition and live with weight gain and potentially a second serious medical condition or you forsake your mood and sanity in order to keep your body at a healthy weight.

My client are I are currently focusing on the myriad other benefits of exercise and proper nutrition; in particular those related to risk of osteoporosis (she’s menopausal and has had several broken bones in her lifetime), improved sleep (often a challenge for those suffering from mental illness) and mood enhancement (we all need more ‘happy’).

In addition, we’ve done some research and discovered that there’s another drug she might be able to take in place of the Olanzapine.

There are many other classes of prescription drugs that can hinder weight loss and even cause substantial weight gain, including;

  • anti-histamines (including over-the-counter varieties) that increase appetite
  • anti-hypertensives (‘beta blockers’) that cause fatigue and a concomitant reduction in daily activity
  • corticosteroids (used to treat asthma and arthritis) affect metabolism and increase hunger
  • anti-depressants that increase food cravings
  • anti-psychotics that ‘flatten’ your mood, sap your energy and affect your body’s sensitivity to insulin (eventually resulting in Type 2 Diabetes…)
  • anti-seizure and mood disorder drugs can cause as much as a 10 pound weight gain in just a few weeks

Given that many of my readers are likely to have taken, or are currently taking one of the above medications, I thought I’d share some tips for researching the side effects of common prescription medications.

  • start by reading the literature that came with your prescription; sounds simple, but many people don’t bother. Either because they trust their doctor and pharmacist to make the right choice for their health OR they simply can’t read the small print on the accompanying pamphlets (definitely a problem for those of us in our 40’s and beyond…)
  • do some online research; beware of doing a generic Google search. All you’re likely to turn up are anecdotes, message boards and watered-down information, at best. Instead, try a Google Scholar search. You don’t need to be able to read the articles yourself (some scientific writing is hard for even other scientists to comprehend…) ; just scan the summaries and see whether there’s likely to be anything useful in the article. Click on the video below to see how I use Google to find fact-based sources of information.
  • take the results of your online search to your doctor; We always assume that our doctors are apprised of the most recent research, yet the sheer volume of research generated on a weekly basis makes this next to impossible (unless your doctor spends more of their time reading journals, than seeing patients…).

Have you ever experienced weight gain while taking prescription medication?

How did you deal with it?


Disclaimer: While I am a certified Personal Trainer, I am NOT a medical professional. Please see you doctor or pharmacist to discuss concerns about any side effects your medications may be causing.



  1. Great info Tamara! I always get more info before I take any medication, prescribed or not.
    Jill @ Fitness, Health and Happiness recently posted…Ultramarathon Monday – How Far and How Fast GiveawayMy Profile

    • Thanks Jill. I try and read all the fine print too, but what if you need to take the medication despite the side effects?

      • That is why educating yourself is so important. Talk to your doctor about alternatives and ways to minimize side effects. I know too many people that take what the doc says with blind faith and just accept what they are told side effects and all. Of course, I don’t mean life threatening situations. I think sometimes people think that have to just get comfortable with being uncomfortable and never question. A long time ago that was me until I decided to take ownership of my health.
        Jill @ Fitness, Health and Happiness recently posted…Ultramarathon Monday – How Far and How Fast GiveawayMy Profile

        • Agreed! So many people leave their health up to a person they see perhaps once a year. Gotta be proactive!

  2. Great info….way to research so much…I would be lost in it all.

    I have not experienced weight gain from pres. drugs but, I swear sometimes my mind acts as though I am on drugs and it DOES seem as though I eat uncontrollably and mindlessly ….. I say don’t do it and my mind and hands are already grabbing it and down the hatch the food goes. It’s def. a (80%) mental challenge for me and more of a (20%) physical challenge of getting out of the kitchen. 😉
    Kathy recently posted…Tomorrow is June 1st?? How is today going??My Profile

    • Well Kathy, you have actually experienced weight gain from a different drug; food! Uncontrollable eating often stems from the interaction between the components of food and our brain chemistry. Sugar is probably the worst culprit!

  3. Really interesting & informative post!!! I am pretty tired so going to come back & reread it later to digest more – you know me Tamara – always tired right about this time. 😉

    Thank you for sharing this – so many probably have questions but afraid to ask!
    Jody – Fit at 55 recently posted…Gratitude Monday & Plain Gratitude; KindRunner Too!My Profile

    • Thanks Jody! Hope you got a bit of sleep today 😉
      Thanks again for all of your shares and help with my Vancouver Blogging contest!

  4. Great article Tamara! Good info for everyone to be aware of.
    Tiffany recently posted…10 Tips For RV Meal PlanningMy Profile

  5. I stalked your FB post on this as it was something I STRUGGLED with when I was a trainer, too.
    Miz recently posted…I never felt stoppable.My Profile

  6. Thanks for sharing this (and all the research involved!). I always wondered if it was an excuse or a real issue.
    Kim recently posted…Early MorningsMy Profile

    • Perhaps a bit of both, depending on the circumstances and the person? Certainly some of us are more than willing to lay blame on things other than our own choices…

  7. this is a huge issue and i’m glad you covered it. i have a friend who was on seizure meds that made her gain 80 lbs. she’d tried everything under the sun to help her seizures, but that was the only drug that worked. she was able to try a brand new drug a few years later, but still has issues losing.
    calee recently posted…PS I was featured today …My Profile

    • Calee, I feel for your friend. It’s really a nasty position to be in.
      Thankfully drug companies are always coming out with new options. I think the trick is to stay on top of the research and get informed.
      Are you going to Fitbloggin this month? Would love to meet IRL!

  8. Sheelagh says:

    That is really cool I never knew that u could do that

  9. EXCELLENT points! As well, I am impressed with how you shifted your client’s focus to the myriad of other benefits of exercise. Exercise itself helps produce many of the “medications” we need.
    KymberlyFunFit recently posted…Drenched 5K Run is Coming: Ready for Some Summer Fun?My Profile

    • Thanks Kymberly. The mental part of training is always so much more difficult that simply creating programs…

  10. Great post! I gained about 20 pounds in college when I had to go on anti-depressants that helped my heart condition. I still haven’t gotten the pounds off. It’s extremely frustrating.

  11. Yes, I have certainly heard of that issue with the newer atypical anti-psychotic drugs. It disturbs me that they are marketed on TV so heavily, especially Abilify. The NYT had an article about it: http://www.nytimes.com/2012/09/25/health/a-call-for-caution-in-the-use-of-antipsychotic-drugs.html?_r=0
    Mary @ Fit and Fed recently posted…PT for Back-Related Hip Pain- Done!My Profile

    • Mary, thanks for sharing. I hadn’t seen this article before. I am always very skeptical of pharmaceutical companies’ interests. They seem to be largely financially driven…

  12. Since starting my weight loss journey I have been wondering about this. I take an anti-depressant daily. I have read the info that cane with it but I fave been on it for over 3 years now I can’t tell you what it said. Great suggestions. I am

  13. YES!

    I was put on Abilify the same week that my hip died. It is well known for weight gain (about 10# on average) but also can cause high blood sugar. (more weight gain). With my messed up metabolism and the forced lack of exercise, I put on 30# in about a month. It has not gone away.

    (I think when you stop taking a med, the weight gain should go away too).
    deb roby recently posted…Preview of FitBloggin13. Dealing with InjuriesMy Profile

  14. I’m impressed, I have to admit. Seldom do I come across a blog that’s both educative and amusing, and let me tell you, you’ve hit the nail on the head. The issue is an issue that not enough people are speaking intelligently about. I am very happy that I stumbled across this in my search for something regarding this.
    lose weight exercise plan recently posted…lose weight exercise planMy Profile

  15. You fellas have a Facebook fan page? I’m diggin all this, hook me up with a klonopin and clonazepam and anxiety or depression link and I’ll send you a like 😀