10 Ways Stress Makes You Fat and Diabetic | Chris Kresser
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10 Ways Stress Makes You Fat and Diabetic


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In the first part of this series on diabesity and metabolic syndrome, we “got under the hood” to look at the underlying mechanisms of both obesity and diabetes. We’ve now moved on to discussing the environmental and lifestyle risk factors that drive these conditions. In the last article we learned about the top 3 dietary causes of diabesity. In this article, we’re going to see how stress can independently cause both obesity and diabetes.

A huge – and I mean huge – amount of research over the past two decades shows that stress causes both obesity and diabetes in a variety of ways. Studies also show that stress makes it hard to lose weight. This is one reason why some people just can’t seem to lose weight no matter how well they eat or how much they exercise. I believe stress is one of the most important – yet most often ignored – factors driving the diabesity epidemic.

Stress Is a Bigger Problem Than You Think

Hans Selye, the famous physiologist who coined the term “stress”, defined it this way:

…the nonspecific response of the body to any demand made upon it.

The prominent psychologist Richard Lazarus offers a similar definition:

…any event in which environmental demands, internal demands, or both tax or exceed the adaptive resources of an individual…

Most people only think of psychological stress when they hear the term “stress”. When asked what causes stress, they might say things like losing a job, having a fight with your spouse, driving in traffic or getting audited by the IRS.

While it’s true that psychological challenges like this are major stressors, what many people don’t realize is that stress is also caused by physiological challenges, such as:

  • insomnia
  • chronic infections
  • inflammation
  • autoimmune disease
  • environmental toxins
  • dieting
  • too much exercise

Even if your levels of psychological stress are pretty low, any of the conditions listed above can provoke a chronic stress reaction in your body. And as we’ll see in the next section, chronic stress can make you both fat and diabetic.

10 Ways Stress Makes You Fat and Diabetic

When stress becomes chronic and prolonged, the hypothalamus is activated and triggers the adrenal glands to release a hormone called cortisol. Cortisol is normally released in a specific rhythm throughout the day.

It should be high in the mornings when you wake up (this is what helps you get out of bed and start your day), and gradually taper off throughout the day (so you feel tired at bedtime and can fall asleep).

Recent research shows that chronic stress can not only increase absolute cortisol levels, but more importantly it disrupts the natural cortisol rhythm. And it’s this broken cortisol rhythm that wreaks so much havoc on your body. Among other effects, it:

Each one of these consequences alone could make you fat and diabetic, but when added together they’re almost a perfect recipe for diabesity.

Our Bodies Aren’t Made for Chronic Stress

One of the reasons chronic stress is so destructive is that our bodies didn’t evolve to deal with it. We’re set up to handle short-term, acute stress fairly well. In paleolithic times, this might have been caused by getting chased by a lion or hunting for our next meal. In fact, this type of stress may even be beneficial for our bodies because it improves our ability to react to the challenges of life.

What we’re not adapted for, however, is the chronic, unrelenting stress that has become so common in modern life. This type of stress provokes feelings of hopelessness and helplessness – what psychologists call a “defeat response”. And it’s the defeat response that leads to increased fat storage, abdominal obesity, tissue breakdown, suppression of the immune system, and all of the other effects I listed above that directly cause obesity and diabetes.

A Closer Look at Insomnia, Dieting and Exercise

I’d like to take a closer look at three often stressors that can make us fat and diabetic: insomnia, dieting and exercise.

More than a third of American suffer from insomnia, with 42 million prescriptions for sleeping medications filled in 2007. Several studies show that sleep deprivation elevates cortisol and makes it more likely that you’ll get fat and develop diabetes.

A very recent paper showed that restricting sleep to 5 hours a night for just one week significantly reduces insulin sensitivity. Another study earlier this year showed that even one night of sleep loss increased appetite in young, healthy adults. Sleep restriction is associated with impairment of carbohydrate tolerance, and research has shown that a loss of 3 hours of sleep each night causes a weight gain of 4-5%.

It’s estimated that between 50-60% of Americans are dieting at any given time. That’s a huge number. And while it may seem counter-intuitive that dieting contributes to obesity and diabetes, it makes perfect sense when you understand that dieting is a stressor that disrupts our cortisol rhythm.

A 2001 study showed that “cognitive dietary restraint” (translation: stressing about food or doing overly restrictive diets) raises your cortisol levels. Studies have also shown that caloric restriction – as is common in low-fat diets – increases cortisol levels. And a recent study reported on by Stephan Guyenet at Whole Health Source found that caloric restriction is especially harmful when combined with sleep deprivation.

Finally, although not common in the general population, too much exercise can also predispose you to weight gain and diabetes by raising cortisol levels, breaking down muscle tissue and increasing fat storage. This is especially true if cortisol levels are already elevated or disrupted by other stressors like gut infections, insomnia, food toxins or psychological factors.

It’s not uncommon (in the paleo/fitness subculture, at least) to encounter someone who eats well and exercises their brains out, but cannot lose weight.

In fact, several of my patients fall into this category. They are often surprised when I tell them they need to exercise less if they want to lose weight and recover their health. What they may not realize is that cortisol is a catabolic hormone. It breaks the body down.

While this might sound like a good thing for those trying to lose weight, it’s not. Muscle tissue is metabolically active and actually helps us lose weight. A reduction of lean muscle tissue may drop a few pounds in the short-term, but it will predispose you to weight gain in the future by impairing your metabolism. (This is another reason why caloric restricted diets, which break down muscle tissue, don’t work in the long-term and even make things worse.)

So if you’re struggling with weight or blood sugar control, don’t diet, get plenty of sleep and take it easy with exercise. You’ll be a lot better off.

  1. Talbot, Shawn. The Cortisol Connection: Why Stress Makes You Fat and Ruins Your Health, and What You Can Do About It. Hunter House. 2007. pp. 85-86
  2. Talbot, Shawn. The Cortisol Connection: Why Stress Makes You Fat and Ruins Your Health, and What You Can Do About It. Hunter House. 2007. pp. 85-86
  1. Though not a “hard core” insomniac, I have found that when I drink lots of water, don’t drink alcohol and cut out soft-drinks I sleep much better. I definitely believe that stress makes one gain weight differently to simply over-eating.

  2. Mr. Kesser,

    Another cause of physiological stress in the body is apnea. This cyclical pattern of oxygen saturations initiates the fight or flight response in apneic patients and then the hormone and chemical responses in the body. Insomnia and the lack of sleep related to apnea have the same effects on the body. This is devastating, causing further insulin resistance in the diabetic patient.

  3. I was looking for a reference on stress & health to share on my blog and this is perfect. I can clearly see how stress can make you unhealthy. I had no idea that exercise could increase cortisol. Good to know! Thanks!

  4. I know this is a couple of years since the original blog posting, but I just came across this while searching on type 2 diabetes. Read the blog on being skinny as well. Both were quite interesting.

    I am a type 2 diabetic (5 years now). I am 6′ 2″ and weigh 140 lbs. So I am in the category of skinny diabetic. Have been thin all my life. My father was diagnosed with type 2 at 50, my older brother was diagnosed with type 2 at 50, I was as well, and my younger brother is prediabetic.

    My dr. had told me it was most likely genetic, but I can’t help but to think that stress might be involved as well. I’ve thought this for a long time, so it was nice to read this blog that confirms what I had been seeing in my life. I’ve significantly changed my eating habits since being diagnosed. I tossed all junk food almost immediately. I stopped eating foods that had been highly processed: white flour products, sugar, potatoes, etc. I tested frequently after eating to see how my body handled certain foods. But even with significant diet changes and taking metformin, my HA1C is still at 6.4%. My dr. assures me that this is fine and that I’m managing it well. However, now I’m feeling some numbness in my toes, which I’m guessing is neuropathy. Can’t put on weight and barely can maintain my weight. Before being diagnosed it was work to keep my weight up. Now it is even harder. All my blood tests show things are normal for me. So I have to wonder again if stress is what is going on (and lack of sleep).

  5. I don’t want to devalue the whole discussion around obesity because we know it’s a symptom of several different chronic disease states that will kill you all by themselves, whether or not being fat does anything serious to you besides make it more difficult to fit in clothes and move around. But I’m really, really, really tired of seeing obesity being constantly in the spotlight when, in most cases, it *is* just a *symptom* of other problems, and does not happen in every person who is in a chronic disease state.

    I have linked to a Men’s Health article on this subject; if you click on my name it’ll take you right to it. I didn’t want my comment automatically going to moderation by putting the link in the body of my comment.

    Really though, read it. Because everyone’s convinced being fat makes you diabetic (in much the same way, I would imagine, they probably think that having a runny nose gives you a cold), every little bit of news from health writers about “what causes obesity and diabetes” just plays on this prejudice. Meanwhile, there are slender people running around out there with several of the markers for metabolic syndrome, only they’re not fat so their doctors think it’s “hereditary” and immediately put them on drugs.

    I predict that’ll be the next chronic disease epidemic and that we’ll only start paying attention to it when society finally notices too many people are dying young who weigh too little to be doing so.

  6. Another safe, effective, natural way to lose excess weight is seriously to reduce salt intake. It surprises me how seldom this seems to get mentioned on paleo sites. Clearly paleo people had a much lower sodium intake and higher potassium intake than modern eating tends to provide.

    Reducing sodium and eating fresh vegetables and fruit forplenty of potassium reduces fluid retention and so is an excellent way of reducing weight and lowering high blood pressure and risk of stroke, heart attack, diabetes and a host of other degenerative health problems.

    It is not widely enough known that there are many prescription drugs that cause severe salt sensitivity/fluid retention, and for the unfortunate people who are in this situation – and that includes me – salt restriction is extremely beneficial. These prescription drugs include steroids, HRT, most antidepressants, antipsychotics, anti-epileptics and many others.

  7. Chris,

    This is a great article! Thank you! I have struggled with adrenal fatigue since 2008 and this is so similar to the responses because of its relation to stress. Currently I am struggling with it mildly again. Do you recommend anything for the visceral fat storage? I am struggling with that right now badly and cannot get those stubborn 5 pounds off (I am only 4′ 11″), It seems the scale goes up each week. I started taking digestive enzymes hoping that will get my digestion to be normal again.

  8. Lynn, you give me hope! I also have thyroid problems (Hashi’s) diagnosed about a year ago, but I think was probably there for quite a while. My doctor is violently opposed to natural thyroid and says as a doctor she can *never* give a prescription to a drug that is unsafe! (yet she also has pushed and pushed to try to get me to take a statin – which *I* think is an unsafe drug, and useless for women). So after my run-in again with her today I think I have to go on a mission to find a doctor who *will* give me the natural thyroid, and maybe that will help with the insomnia too!

  9. I can relate to Debbie’s frustration. 🙂

    Most people in my family are night owls and sleep onset insomniacs. Until July 2009, it took me:
    30 minutes to fall asleep on an amazing night
    An hour on an average night
    Two to three hours on a bad night.

    Like Debbie, I had tried everything, but I went off gluten and got to the correct dose of natural thyroid med in July 2009. Everything changed. My lifelong sleep onset insomnia was cured. Sadly, the two variables were confounded, but I have read thst insomnia can be associated with thyroid problems. For me though, I really think it was the gluten. The crazy thing is that I had been eating very little gluten anyway; but to a celiac one crumb will cause issues.

    Just want other insomniacs to know there is hope out there…

  10. You know, statements like this: “So if you’re struggling with weight or blood sugar control, don’t diet, get plenty of sleep” just plain make me crazy. I mean no one WANTS to be an insomniac! I sure don’t, but I have been one for many years, and am also now fat and diabetic. But I don’t know any way to *make* myself sleep! When you takes hours to get to sleep, then wake up 2-3 times every night, and toss and turn for more hours before getting back to sleep it only adds to the stress to be told “get plenty of sleep”.
    I mean I can control what I eat, and scrupulously avoid all grains, sugars, and high-PUFA vegetable oils among other things. I can control if I exercise or not. But I can’t control sleep. Over the years I have tried every “natural” solution I could find such as melatonin, magnesium, meditation …. well no point listing them all. I’ve tried just about everything except hard-core prescription sleeping pills. I don’t even want to go there. So “get plenty of sleep” has been an utterly meaningless phrase to me for years.
    Finally, when nothing else worked, I turned to acupuncture a few weeks ago. Knock on wood, but the last 7-10 days I have slept better than I have in YEARS. I still toss and turn a bit before going to sleep, but maybe 20 minutes instead of 2 hours. I still wake up once or twice during the night, but get back to sleep pretty quickly instead of hours again. Is it the acupuncture? Is it just an anomalous blip and I’ll be up half the night again in another week?
    I don’t know, but this last week I have been waking refreshed, and WANTING to  do some sort of exercise, and feeling pretty much like a “normal” person – most unusual. 😀
    But believe me, any insomniac would dearly love to sleep, so saying “get plenty of sleep” is like waving a red flag! Grrrrr. But other than that I’m loving your blog.

  11. And what is dieting – anything different from eating whatever is meant for eating and tastes good. In present time, any limiting of foods eaten is called a diet. So if somebody does not eat sugar it is a diet.
    And I agree with Jesse – if someone read this blog entry, with no previous knowledge of you writings, or used it as single piece of information, as argument, they can come up with the following conclusion – “Eat as much of anything as you want and just take it easy.”
    Many people blame stress for every health problem (especially diabetes) so that they can lift responsibility off themselves. What is the  contribution of stress to modern health problem relative to eating habits? Could you write in easily taken away message?

    • Stan,

      The studies I mentioned in the article found harmful effects from “cognitive dietary restraint” and caloric restriction. That isn’t the same as your definition of dieting, although if you take it literally avoiding sugar, processed and refined carbohydrates and industrial seed oils would NOT be dieting because we were never meant to eat those foods.

      The contribution of stress to modern health problems, relative to eating habits, is just what I said. Overly restrictive diets – particularly those that involve caloric restriction – can disrupt the cortisol rhythm, which in turn has all of the effects mentioned in the article. The takeaway is to eat nourishing, nutrient-dense, toxin-free foods without restricting calories and take steps to manage your stress.

      The reality is that stress can be blamed, at least in part, for every health problem. And often it plays a primary role. For example, many of my patients already eat a very good diet when they come to me. Yet they are still struggling with chronic health problems. In almost every case, their cortisol rhythm is seriously disrupted by stress. That stress may be psychological, or it may be physiological (chronic illness, infection, inflammation, etc.) as I pointed out in the article. The key to getting well for these people is to address the stress physiology. That hardly lifts responsibility off of their shoulders. On the contrary, it puts responsibility firmly in their hands, because they need to take concrete steps to mitigate the effects stress is having on their bodies.

  12. Sorry, I was unclear. That wasn’t my quote of your statement either. It was my quote of someone taking your statement out of context.

  13. If there’s evidence enough from the present, is there really a need for speculation about how we might have evolved?
    The problem with speculation is that the world is complicated. We could be missing something, or there could be evidence that hasn’t been found yet that suggests the opposite of what we thought. Like that paper in PNAS this week about how paleolithic people eating starchy plant foods that required cooking might’ve been more widespread than was thought.
    As for evidence, I would be cautious about putting forward an article in Medical Hypotheses or an animal study as good evidence for what happens in humans. Also, is a person with Cushing’s disease really comparable to a normal but stressed person? Other than that, it seems okay.
    Though it seems like your concluding statement could be VERY easily taken out of context. “Eat as much of anything as you want and just take it easy.”

    • Jesse: that wasn’t my concluding statement. That was your paraphrase of my statement, which is inaccurate.

      Here is my statement, word for word:

      “So if you’re struggling with weight or blood sugar control, don’t diet, get plenty of sleep and take it easy with exercise. You’ll be a lot better off.”‘

      If you’re going to put something in quotation marks and attribute it to me, please make sure it’s accurate.

  14. What’s your point, Jesse?

    The evidence is clear that dieting, insomnia and over-training contribute to diabetes and obesity.  I presented it in this article.

    There’s plenty of anthropological evidence about paleolithic lifestyle.  Obviously you’re not going to see any double-blind, clinical studies.  But common sense is useful here.  There was no artificial light, computers, television, coffee, etc. at that point.  Our ancestors weren’t stupid enough to sleep where predators would get them, or we wouldn’t be here.

    Of course there were periods of food scarcity.  Of course people had bad nights of sleep. But it’s reasonable to assume that insomnia wasn’t nearly the problem it is today, and that no one was engaging in long-term, voluntary caloric restriction.

    I didn’t say only jogging.  I said any kind of over-training.  Paleo people had light to moderate activity levels in general, punctuated by short bursts of intense activity.

    • About that insomnia thing: I have suffered from it. And from what I can tell it mostly came from diet. If I ate badly, including high amounts of grains (especially wheat) and seed oils (too much omega-6), I had a hard time going to sleep and sleeping enough, and I would wake up groggy. Now I find I get properly tired at night like I’m supposed to, and I wake up early enough to not feel like I have wasted my day. I’m a bit headachy at first but it disappears soon after I get vertical. (Hopefully I will figure that out eventually. Not there yet.)

      I suspect this will be like the assuming that obesity causes diabetes–another getting cause and effect mixed up. If someone is healthy they will sleep better. If they’re eating crap, they won’t be healthy, at least not forever.

      Another problem with sleep issues is too much light in the bedroom. I still need to tackle this one but it doesn’t stop me from getting to sleep. However, it may affect the quality of my sleep; it may even explain my morning headaches. That’s next on the agenda, as I have blackout blinds on order now.

  15. So they didn’t have long-term food scarcity?
    So jogging in particular is the problem? Seems like there are a lot of other activities that should count as exercise.
    I was kinda thinking maybe they just didn’t have a chance to sleep. Predators, hard times, that kind of thing.
    Is there evidence for your description of paleolithic life, or are you just making assumptions about it like I am?

    • How do you get long-term food scarcity when you’ve been taught that all you have to do to have a meal for the day is go out and hunt or pick some? If the food’s that scarce, you’re not stuck sitting in one place–you can follow the herds and *move*.

      The trouble with a lot of these so-called “critiques” of hunter-gatherer life is they’re made by farmers who think like farmers. This is not farming. Think about it again.

  16. Long-term caloric restriction isn’t remotely the same as intermittent fasts.

    And yes, paleolithic people didn’t jog or exercise on Stairmasters and treadmills, and there’s no reason to assume they had trouble sleeping since almost all causes of chronic insomnia weren’t present.

  17. That’s an interesting idea… you’re saying that our paleolithic ancestors didn’t sometimes have periods of food scarcity, that they generally got plenty of sleep, and that they didn’t exercise much?

  18. Yes, I’m familiar with Matt and we’ve corresponded a few times.  I wouldn’t disagree with his approach but I think there are limitations to the Barnes model.  Body temperature is definitely and important marker, and overfeeding seems to work in some cases, but I don’t think it’s an appropriate strategy in others.  Certainly I agree that reducing stress is an important part of healing metabolism, as I’ve written about here.

  19. Are you familiar with Matt Stone of 180 Degrees Health? His idea is that many people have underactive metabolisms due to stress and poor diet and that you should reduce stress and overeat in order to raise the body temperature to 98.6. Overfeeding to raise metabolism is an alternative to manipulating body temperature using thyroid, as advocated by Broda Barnes and followers. Allegedly Barnes et al have a tremendous history of treating and preventing disease. Any thoughts?

  20. One line in particular struck me in this article — that our bodies aren’t made for chronic stress. How true. We live completely out of any semblance of a natural element. For instance, human beings weren’t designed to go 70mph on a freeway while dodging cars and watching for hazards. Other drivers and their rage make it worse. In nature, a cheetah goes 70mph, not a man. There are countless other examples, but they all add up to the kind of stress that is not innate to the human organism. It’s surprising we cope at all.