Weight Loss and Depression: What's the Connection?

Picture this: You bump into a friend you haven’t seen in forever at the grocery store. You ask them how they’ve been doing, and they say they’ve just gone through a bad breakup. They’ve been depressed, making them feel tired and unmotivated for weeks.

They also tell you they’re down three pants sizes and can finally fit into their favorite old pair of Levi’s.

Part of you is concerned — after all, you know depression can be serious — but on the other hand, can’t weight loss be a good thing? And is depression weight loss even a thing in the first place?

As you might’ve guessed, the answer isn’t as black-and-white as it may seem. One of the most common symptoms of depression is weight changes, which can look like weight loss or gain.

Healthy weight loss, especially under the supervision of a healthcare provider, can be good. But weight loss because of a mental illness — even if it’s unintentional — isn’t some kind of “silver lining.” It can lead to potentially harmful consequences to your well-being if it’s not taken seriously.

Still, it’s fair to wonder, Why does depression cause weight loss?

Below, we’ll break down the connection between weight loss and depression so you can have a better understanding of why it might happen and what to look out for.

From major depressive disorder (MDD) to seasonal affective disorder (SAD), there are many kinds of depression. Some people might experience depression temporarily — like if they’re going through a rough breakup — while others may have chronic depression.

Though it looks different to everyone, depression is typically diagnosed after you’ve had persistent symptoms for at least two weeks. 

Emotionally, depression can take a major toll, making you feel sad, irritable, helpless or fatigued, among other symptoms. It can also manifest physically, causing aches and pains, headaches and unintentional changes in weight.

A 2010 study showed a correlation between obesity and depression, with obese adults having a 55 percent increased risk of developing depression. Similarly, 58 percent of those with depression have an increased chance of developing obesity. 

There’s also a connection between weight loss and depression. The numbers you see reflected on the scale can be affected by: 

• Mood changes

• Physical symptoms

• Medication side effects

• Changes in the brain 

Let’s unpack each of these.  

Mood Changes

Changes in mood are often an indication something isn’t quite right. When you’re depressed, you’re more prone to certain symptoms that can cause a shift in eating habits, often unintentionally.

These symptoms can include: 

• Feeling emotionally drained. When you’re depressed, mustering up the mental energy to throw together a quick meal can feel like a Herculean effort. As a result, you might find yourself eating less simply because it feels like too much exertion. 

• Losing interest in things you once enjoyed. Maybe you once looked forward to sharing a large pizza with your partner every Friday night on the couch while binge-watching your favorite Bravo shows. But now, you feel completely disinterested — even when it comes to cravings for your go-to comfort foods, like cheesy carbohydrates.

• Having trouble making decisions. Making even the seemingly smallest choices can feel overwhelming. Am I hungry? Not really, but I should probably eat something. What do I want for dinner? Hmm…cooking feels too hard. Should I order in? But nothing sounds appealing. As a result of this wishy-washy mindset, you wind up feeling defeated and don’t bother eating anything at all.

Other Physical Symptoms

Other physical symptoms of depression can cause a loss of appetite. 

Not only can you feel emotionally drained when you’re depressed, but you might experience physical fatigue too. Your body may feel tired, overriding any desire to put food in your body. Nausea and stomach pains can also contribute to eating less. 

Psychomotor agitation, which involves fidgeting and pacing, is yet another physical factor that may come into play for some people with depression. By burning your energy levels, these movements can eat up calories or reduce your appetite, thereby causing weight loss.

Medication Side Effects

Some medications (including certain antidepressants) are known for side effects like weight gain. But some antidepressants are associated with weight loss, such as:

• Sertraline (Zoloft®) 

• Citalopram (Celexa®) 

• Escitalopram (Lexapro®)

• Bupropion (Wellbutrin®)

Bupropion, in particular, has been strongly linked to small amounts of weight loss as opposed to weight gain and increased appetite. Research shows that people who use bupropion to treat depression generally gain less weight, with others even losing weight.

A 2016 study found that non-smokers using bupropion lost an average of 7.1 more pounds than participants on fluoxetine, though cigarette smokers actually gained weight when using the drug.

Another review published in 2019 found that while the most popular medications used to treat depression caused weight gain, bupropion actually caused people to lose weight instead.

Changes in the Brain

Depression changes the chemistry of your brain, and some experts believe there’s a correlation between these chemical imbalances and weight loss. 

A 2016 study revealed that depression can increase or decrease people’s appetites, indicating that depression has the ability to make you feel more or less motivated by food as a “reward.”

In other words, just like depression can completely derail your motivation to work out or spend time with friends, it can have a similar effect when it comes to your desire to eat (or not eat).

Of course, depression isn’t the only reason you might be experiencing unexplained weight loss. Other factors like emotional eating, eating disorders and other body image-related issues can be contributors.

It could also be because of an underlying illness you’re unaware of. It might be due to grief, stress or a side effect of a medication you’re taking — or something entirely different.

The point is, weight loss can occur for a number of reasons. Regardless, the best step you can take is to speak with a healthcare provider about your concerns. They can help get to the bottom of what’s actually going on in your body (and your mind) and come up with a treatment plan that works for you. 

So, we’ve established that depression can cause weight loss. But if we turn the tables, can weight loss cause depression?

That depends. 

Weight loss can actually be good for your mental health — under the right circumstances. A 2021 review revealed that obese patients who followed calorie-restrictive diets experienced a decrease in depression symptoms. 

It’s important to note, though: Depression shouldn’t be seen as some kind of weight loss technique. In some instances, the weight loss itself is considered a result of malnutrition — which isn’t healthy at all. 

Additional research supports this relationship, pointing to certain vitamin and mineral deficiencies that are common among depressed folks.

If, for example, you have low levels of vitamin D, folic acid or zinc — all of which are important for helping your body function properly — it can have an impact on your mental state. As a result, your nutritional deficiency could indirectly increase your risk of developing depression. 

Let’s recap: Healthy weight loss can be good. But weight loss as a result of depression is not. Depression is a mental health disorder that requires attention, so the sooner you seek help from a healthcare professional, the better.  

Fortunately, depression is very treatable. Depending on your symptoms, your healthcare provider might recommend:

• Medication. Medications like antidepressants are highly effective for treating depression, as they work to balance serotonin and other brain chemicals. However, there’s no one-size-fits-all approach. Everyone has different mental health needs and tolerances, so the right medication is entirely dependent upon the individual. Based on the severity of your symptoms, how long they’ve persisted and factors like other health conditions you may have, your provider can come up with the best plan for you.

• Therapy. Therapy often goes hand-in-hand with medication. Like medication, there are many types of therapy, including cognitive behavioral therapy (CBT) and psychodynamic approaches(aka talk therapy). There’s even online therapy if you prefer talking to someone from the comfort of your home. Not quite ready for therapy? Try opening up to a loved one, like a family member or friend. When you’re honest about your struggles, they can show up and give you the support you deserve.

• Lifestyle changes. Certain substances can have a major impact on your mood, like caffeine, alcohol and drugs. If you’re struggling with depression, your provider may recommend cutting back on daily cold brews or Margarita Mondays. They might also suggest incorporating certain lifestyle changes into your routine, like physical activity or journaling, which are both evidence-based coping strategies for dealing with depression.

Want to learn more about depression and other mental health disorders? Our mental health resources are always available to check out for additional information.