Antidepressants and Weight Gain

You or someone you know recently started taking antidepressants. And the most obvious side effect was also noticeable: weight gain.

I’ve observed this effect repeatedly – people on antidepressants have a harder time losing fat, and getting started with an exercise routine.

And more and more clients, readers, and audience members have been asking these questions. Plus, I’ve been giving a lot of seminars on exercise and mental health (HR managers – take note 😉

Original source: here.

But I didn’t know the ins-and-outs of it. After all, I’m not a pharmacist. So I got a pharmacist to help me dig deeper into this area. Her name is Kate Takopoulos, and she’s the only Registered Pharmacist (that I know of) who is also a Certified Clinical Nutritionist. Her unique knowledge in the area of drug-induced nutrient depletions combined with the expertise in clinical nutrition are the focal point of her practice.

So everything that we’re going to cover in this article is from Kate’s research.

Speaking of which, what are we going to cover?

• Do antidepressants really make you gain weight? Or is it just something people blame weight gain on? Like being “big boned”, or having a “slow metabolism”.

• If the weight gain is real, why do antidepressants make you gain weight? What are the mechanisms at work?

• Do all antidepressants cause weight gain, or are some better than others? What are the differences between different antidepressants in terms of their effect on weight?

• If someone is on antidepressants, and has gained weight, what can be done about it? How can they lose weight?

And of course, if you need help on the medication side of things, figuring these things out, feel free to contact Kate. And if you need help on the exercise and behavior modification side of things, you can feel free to see if you qualify to work with us, by filling out this questionnaire.

Do Antidepressant Really Make You Gain Weight?

The answer is a definitive “maybe” (don’t you hate it when I do that?) 🙂

Here’s the scoop: yes, some antidepressants make you gain weight. But not all of them. It’s inaccurate to say that 100% of people who go on any antidepressant gain weight. Whether weight is gained or not is dependent on a few factors, like:

• Which antidepressant is being used. Some cause more weight gain than others

• Duration of treatment. For how long an antidepressant is taken

• Physical characteristics of the person. Are they prone to obesity to begin with? How is their liver function? And more.

• The rest of their lifestyle – diet and exercise

Having said that, yes, many studies (and more importantly, people) observe that effect: often (again, not always) weight is gained while taking antidepressants.

Why is Weight Gained When Taking Antidepressants?

As if depression isn’t bad enough, now there’s weight gain to go along with it. That, in and of itself is depressing. But why? What is it that causes weight gain? Do the laws of calories in / calories out change? That’s what we’ll explore in this section.

Mechanism #1: Increased Appetite

Do you know what controls your appetite? It’s more complex than you’d think, and there are many factors, including the hormones in your stomach, how you grew up, and many others. But one neurotransmitter (brain hormone) that controls appetite is called “serotonin.” You may have heard of it referred to as the “happy chemical.”

When you eat, your serotonin levels gradually rise, and then you get to the point of feeling full (and happy), so you stop eating. That’s what happens when everything is working properly. The problem happens when serotonin doesn’t transmit its “message.” In other words, serotonin (as do other neurotransmitters and hormones) attaches to a receptor. Think of it like a lock and key. Once the key goes in the lock, it opens a door. Same with serotonin. Once it (serotonin – the “key”) attaches to its receptor (the “lock”), you feel full. But antidepressants can block that lock. In other words, imagine breaking a key inside the lock, and leaving it there. Nothing else will be able to get in. And that’s what happens with some antidepressants – they block serotonin receptors, so it decreases your awareness of your full signals.

Mechanism #2: Carbohydrate Cravings

Piggybacking on mechanism #1, carbohydrates can raise your levels of serotonin. But again, if you never get the “pleasure” of carbohydrates, you’ll keep eating them, seeking the pleasure, but the pleasure isn’t there, because serotonin is blocked.

Mechanism #3: Increased Thirst

Some antidepressants (lithium, specifically) causes increased thirst. And the increased thirst, in combination with the carb cravings makes people go for sweet drinks. Not exactly water or tea.

And of course, liquid calories are much easier to overconsume than solid calories.

Mechanism #4: Fluid Retention

Fluid retention is another reason why weight is gained. Yes, it’s not all fat. Often, this fluid is in the lower body, too.

Mechanism #5: Inhibition of Thyroid

The thyroid is the master gland that regulates the metabolism. When that slows down, your body temperature decreases, and you burn fewer calories at rest. Other signs of a slow thyroid are:

• Low energy levels

• Constipation

• Thinning of the outer third of the eyebrow

• Cold hands and feet when other people around you are comfortable

Mechanism #6: Decreased Physical Activity

Some antidepressants act as sedatives, so not only does voluntary physical activity (exercise, active hobbies, etc.) decrease, but also involuntary physical activity decreases. What is involuntary physical activity? That’s things you don’t really think about. Like when you’re sitting at your desk, tapping your finger, or bouncing your foot, and so on.

Small things like that can add up to as much as 900 calories per day. So in that way, antidepressants can really affect the “calories out” side of the equation. That is, even if your eating doesn’t change (which is a big “if”), you’ll be burning hundreds of calories per day fewer.

Mechanism #7: Dry Mouth

Some antidepressants have the side effect of a dry mouth. To combat that, it leads people to drink “richer” drinks, like dairy, or cream-based drinks. Those drinks have hundreds of calories. Water, tea and coffee have 0, or very close to it.

So we’ve identified 2 reasons why people might drink high-calorie drinks when they have depression: dry mouth, and increased thirst.

Mechanism #8: You Were Underweight to Begin With

And mechanism #8: for some people the depression causes them to actually lose their appetite, and with that comes weight loss. But it’s not the good kind of weight loss. It’s losing muscle, fat, bone, water, etc.

So if a person is underweight when they have depression, and the antidepressants make them gain weight, in that case, it’s a good thing.

Weight Gain Differences Among Antidepressants

Not all antidepressants are created equal. Some cause weight gain, and others don’t. As far as the research is concerned, the SSRI (Selective Serotonin Reuptake Inhibitor) that makes people gain the most weight is Paroxetine (Paxil). One study found that the average weight gained is 7% of a person’s baseline. So if you weigh 150, and you start taking Paroxetine, you might gain an average of 11.5 pounds.

Other SSRIs, like Citalopram (Celexa), Escitalopram (Cipralex), Fluoxetine (Prozac and Sarafem) also cause weight gain, but not to the same extent as Paroxetine.

According to one study, the average weight gain with lithium is 5% of your body weight.

Among old school antidepressants (called “tricyclic antidepressants”, or TCAs), the biggest offender (in terms of weight gain) is Amitriptyline. According to one study, people who take it gain 1.5-2.4 kg over a 12-week span.

One antidepressant has actually been found to cause weight loss. That’s Bupropion (Wellbutrin). The average person who uses Bupropion loses 7.1 pounds over a 2-year period.

But again, what I want to emphasize is that these are averages, and the person-to-person variation in weight gain is significant. For example, one person may gain 20 pounds on Paroxetine, and someone else may gain nothing. Again, there are individual factors at work, as was mentioned earlier.

What to Do to Lose Weight on Antidepressants

You might be reading this, and see 8 different mechanisms by which antidepressants make you gain weight. You read the stats for different antidepressants, and how much weight each one makes you gain. So understandably, you might be feeling pretty pessimistic. Well, turn that frown upside down. Because just like every good Hollywood story, we’re going to finish this article on a good note – what you can do if you’re using antidepressants, and they’re causing weight gain.

In Kate’s opinion, antidepressants have their place – to treat the symptoms temporarily, while searching for and addressing the underlying cause(s) of the depression (isn’t it cool to hear a pharmacist say that?). Underlying causes may be:

• Stress

• Poor nutrition

• Physical trauma

• Lack of sleep

• Hormonal imbalances

• Poor digestion

• Other medications

• Inflammation

…and others.

I’ll quote Kate directly, because she says it very eloquently:

By addressing some of these potential underlying factors, it would help prevent the progression of the disease and restore the balance that caused the symptoms of depression to begin with. I believe that people should have access to the tools that would help them understand the root cause of their illness. Every treatment plan should focus on nutrition and physical activity [emphasis is my own] as part of reaching person’s goals for creating their wellness.

If you’d like to get in touch with Kate to help you evaluate your medications, and see what can be done to manage the side effects, you can do so by emailing her here. And if you want some help in exercising properly when you have depression, you can see if you qualify to work with us by filling out this questionnaire.