How Does Stress Affect Appetite?

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This article was written by Registered Nutritionist and Dietetically Speaking intern Sophie Gastman and reviewed by Registered Dietitian Maeve Hanan.

For more information about managing stress eating, check out the Exploring Emotional Eating Online Course.


The majority, if not all of us, have experienced stress at some point in our lives. A UK-wide stress survey commissioned by the Mental Health Foundation in 2018 found that almost ¾ of adults had felt so stressed in that year that they felt overwhelmed or unable to cope (1). Considering the events of 2020, it is unlikely that this statistic has improved since.

We know that stress is often involved in the development of many health issues, but did you know it can have quite the impact on your appetite too?  

Appetite and Stress

Appetite differs from hunger and is defined as ‘the desire to eat food’, sometimes due to hunger signals but not always. It can be affected by many factors, including the environment, lifestyle, physical and mental health, and as mentioned already – stress. 

The effects of stress on appetite are experienced differently by different people.

Various research has shown that about 40% of people eat more and 40% eat less when stressed, whilst roughly 20% don’t change their food intake at all (2).

Other studies have shown the percentage of those who eat more than usual during a stressful experience is as high as 60% (3). 

Another reason for individual differences in our appetites in response to stress could be down to the nature of the stress and whether or not the person is prone to emotional eating. Research has identified ‘restrained eating’ as a predictor of overeating under stress, meaning that those who usually make a conscious effort to restrict their food intake are more likely to overeat as a response to stress (4).

A cross-sectional study from 2000 showed that restrained eaters had an abnormally increased appetite in response to work stress compared to ‘free-eaters’ who didn’t change their food intake at all (5). The reason for this response in restrained eaters is not well documented. However, a suggested explanation is that dieters tend to abandon their inhibitions around food as food control becomes less important under stressful situations.

Physical hunger may also play a role in this along with the ‘scarcity effect’, which means that we may become more obsessed with certain foods if we feel they are off-limits or scarce. 

Changes to Hunger in Response to Stress 

When we begin to experience stress, a cascade of reactions start to occur in the body. The hypothalamus releases corticotropin-releasing hormone (CRH), whilst the pituitary releases stimulating adrenocorticotropic hormone (ACTH) into the circulation. ACTH then binds to a receptor in the adrenal cortex. This binding of ACTH is what triggers the release of glucocorticoids, which includes the well-known stress hormone cortisol. 

In instances of long-term chronic stress, the release of glucocorticoids are one of the reasons why we may feel the urge to overeat. Once they are released, they act on different appetite-regulating hormones, such as leptin, ghrelin and neuropeptide Y (6). 

Hunger Hormones 101:

  • Leptin, released by fat cells, is sometimes referred to as the ‘satiety or ‘fullness hormone’ as its role is to inhibit hunger and regulate energy balance. 
  • Ghrelin is often called the ‘hunger hormone’ as it stimulates appetite and increases food intake. 
  • Neuropeptide Y is known as an orexigenic peptide. This essentially means it is an appetite stimulant and will increase the motivation to eat and delay the feelings of satiety (7).

Glucocorticoids stimulate leptin release, which you would be correct in thinking should suppress appetite, but instead, they contribute to leptin resistance by reducing the sensitivity of the brain to leptin, meaning the appetite suppressing effects of the hormone are reduced (8). Similarly, glucocorticoids can also contribute to insulin resistance, which affects the ability of insulin to inhibit neurotransmitters, such as Neuropeptide Y (9).

In addition to all of this, chronic stress causing increases in glucocorticoid secretion also raises circulating ghrelin levels (10) – a triple whammy on our appetite and feelings of hunger. 

The opposite is true for short-term, acute stress, which tends to decrease appetite (11).

This is due to the release of CRH from the hypothalamus, which can act to inhibit appetite via a huge network of cells that modulate energy metabolism (12). The appetite suppressing effect in response to acute stress physiologically makes a lot of sense, as energy may need to be diverted to more important tasks, such as responding to the stressful situation (e.g. escaping from danger), rather than seeking out food. 

Another factor that may alter our hunger signals in response to stress is the prefrontal cortex. The prefrontal cortex is in charge of regulating our thoughts, actions and emotions and several human studies have shown that stress can impair the function of the prefrontal cortex.

One study demonstrated that moderate psychological stress induced by watching emotionally upsetting films reduced activity in the prefrontal cortex of women (13). Another study in healthy, young men found that acute stress disrupted working memory processing, which is related to the functioning of the prefrontal cortex (14). This helps us to understand why some people turn to overeating when exposed to stress as there is an element of a loss of self-control when the functioning of the prefrontal cortex is reduced (15). 

Hyper-Palatable Foods and Stress 

How many times have you turned to a bar of chocolate or your favourite comfort food when you’re feeling stressed out? Well, this phenomenon is more common than you think and there is accumulating evidence for a proper scientific explanation. Research has suggested that highly palatable food, (i.e. foods high in sugar, salt and fat), can activate the brain reward system in a similar way to drugs, such as opiates (however this isn’t the same as drug addiction) (16).

One study showed that women who reported greater stress in their lives felt a greater drive to eat and specifically ate more hyper-palatable foods, such as chips, hamburgers and fizzy drinks (17). This explains why we are inclined to use highly palatable foods in an attempt to make us feel better during stressful times. Fat and sugar will activate the brain reward pathways and are also an inexpensive way of experiencing short-term pleasure. 

We can also develop a habit of turning to food as our main coping mechanism in response to stress, especially if we have not developed other coping strategies or have learned this in childhood from observing those around us. It isn’t wrong to use food as a coping mechanism, but this can become an issue if it’s our only way to cope or if this feels chaotic. 

Other unhelpful coping mechanisms such as relying on alcohol can also impact our food choice; for example, some people feel less control around food when drunk, whereas in other cases food intake can be neglected when drinking. 

Stress, Sleep and Appetite 

About 1 in 3 people in the UK suffer from sleep deprivation or insomnia and the most common causes are normally stress-related. It may seem like the main side effect of lack of sleep is feeling a bit tired and groggy the next day, but not getting enough shut-eye can inadvertently impact your appetite too.

The Wisconsin Sleep Cohort Study found those habitually sleeping for only 5 hours a night had lower levels of leptin and higher levels of ghrelin compared to those who slept for 8 hours (18). Another study found that adults who slept 5-6 hours a day had significantly lower circulating leptin levels (19).

Essentially, this means that you are more likely to feel hungry after not getting enough sleep because your levels of ghrelin, aka the ‘hunger hormone’, increase and signal to your body to eat more food.

Numerous studies have highlighted this, identifying a link between short sleepers (<5-6 hours) and increased irregular eating (i.e. eating more snacks than meals). These studies also identify that short sleep is associated with a higher calorie intake but a lower diet quality (20). 

Interestingly, another piece of research has found that increased daytime sleep in adolescents was associated with greater food cravings and increased caloric intake (21). This means that even those compensatory midday naps might not be doing much to help regulate your appetite either. 

Tips for Stress Management 

  • Identify the root cause – think about what’s actually causing you to feel stressed and see if you can do something to take control of the situation. 
  • Have a support system – make sure you have a good network of people, whether that’s with friends, family or a therapist, who can help you to relax or enable you to see things in a different light. 
  • ‘Me time’ – make sure you’re creating space in your life for ‘me time’. This doesn’t necessarily always mean taking an hour out of your day to put on a face mask and have a bath (although it can be), but it might also mean going for a walk, taking a break from your phone or even just going to bed earlier. 
  • Try to avoid relying on alcohol, smoking or caffeine as a way of coping through stress. It may help you feel better in the short-term but it won’t solve your problems and can lead to other issues. 

If you are struggling with stress you can seek support from your GP or a mental health professional. 

Click here for information and resources about stress from the NHS and here for information from the UK mental health charity Mind

Strategies for Eating During Stressful Times

As much as we might try and use the above tips to manage our stress, it is inevitable that some periods of our lives will be stressful. Here are some strategies for eating during these stressful times: 

Reduce Food Overwhelm:

Go back to basics and focus on convenient options. Handy options include: ready meals, frozen fruit and vegetables, cereal with milk, yogurt, eggs, tinned beans and pulses, nuts, cereal bars etc. 

If You Have a Poor Appetite:

Try eating smaller meals and snacks more often throughout the day. Perhaps try fortifying your meals without adding volume by adding calorie-dense foods such as cheese, butter, oil, cream, nut butter, sugar, jam, eggs etc. It’s important to remember that your body still needs fuel even if your appetite is low. Nourishing drinks may also go down easier as well, such as milky drinks, smoothies and milkshakes. 

Consider a Micronutrient Supplement:

Although it is best to get most of our nutrients from food, taking a vitamin and mineral supplement can help in the short term if you are off your food or not eating as well as you usually do. 

If You Feel Nauseous:

Focus on eating little and often. Dry, bland starchy foods are your friend but try to avoid strong smells and greasy or spicy foods. Eating foods or drinks with ginger may also help. 

If Stress Wreaks Havoc on Your Gut:

Focus on eating little and often may help, along with chewing your food properly and trying to relax at mealtimes. It may also feel more comfortable to avoid too many fried or greasy foods, sweeteners, spicy and acid foods, caffeine, alcohol or any other food or drinks that are ‘gut triggers’ for you. A dietitian can help you with this so that you don’t unnecessarily cut out too many foods, which in itself can contribute to stress. 

If You Experience Increased Comfort Eating or Binge Eating:

First of all, it is important to be as compassionate with yourself as possible, as food is playing a role during a difficult time. It can be helpful to focus on eating every 2-4 hours, and seeing whether you can identify your triggers and unmet needs. At this point, you can think about whether there are additional coping mechanisms, forms of self-care and stress management that you can add in without taking food away. And of course, please seek support from health professionals if you are struggling to manage this by yourself.

If you are struggling to eat well due to stress, don’t forget that you can seek one to one support from a Registered Dietitian

For more information about managing stress eating check out our Exploring Emotional Eating Online Course

References 

  1. Mental Health Foundation. (2018). Stress: Are we coping? London: Mental Health Foundation Available at: https://www.mentalhealth.org.uk/sites/default/files/stress-are-we-coping.pdf   [Accessed July 2021].
  2. Yau, Y. H., & Potenza, M. N. (2013). Stress and eating behaviors. Minerva endocrinologica, 38(3), 255–267.
  3. Weinstein, S., Shide, D., & Rolls, B. (1997). Changes in Food Intake in Response to Stress in Men and Women: Psychological Factors. Appetite, 28(1), 7-18. 
  4. Adam, T., & Epel, E. (2007). Stress, eating and the reward system. Physiology & Behavior, 91(4), 449-458.
  5. Wardle, J., Steptoe, A., Oliver, G. and Lipsey, Z., 2000. Stress, dietary restraint and food intake. Journal of Psychosomatic Research, 48(2), pp.195-202.
  6. Takeda, E., Terao, J., Nakaya, Y., Miyamoto, K., Baba, Y., Chuman, H., Kaji, R., Ohmori, T. and Rokutan, K., 2004. Stress control and human nutrition. The Journal of Medical Investigation, 51(3-4), pp.139-145.
  7. Beck, B., 2006. Neuropeptide Y in normal eating and in genetic and dietary-induced obesity. Philosophical Transactions of the Royal Society B: Biological Sciences, 361(1471), pp.1159-1185.
  8. Zakrzewska, K., Cusin, I., Sainsbury, A., Rohner-Jeanrenaud, F. and Jeanrenaud, B., 1997. Glucocorticoids as Counterregulatory Hormones of Leptin: Toward an Understanding of Leptin Resistance. Diabetes, 46(4), pp.717-719.
  9. Sominsky, L. and Spencer, S., 2014. Eating behavior and stress: a pathway to obesity. Frontiers in Psychology, 5.
  10. Lutter, M., Sakata, I., Osborne-Lawrence, S., Rovinsky, S., Anderson, J., Jung, S., Birnbaum, S., Yanagisawa, M., Elmquist, J., Nestler, E. and Zigman, J., 2008. The orexigenic hormone ghrelin defends against depressive symptoms of chronic stress. Nature Neuroscience, 11(7), pp.752-753.
  11. Charmandari, E., Tsigos, C. and Chrousos, G., 2005. Endocrinology of the Stress Response. Annual Review of Physiology, 67(1), pp.259-284.
  12. Richard, D., Lin, Q. and Timofeeva, E., 2002. The corticotropin-releasing factor family of peptides and CRF receptors: their roles in the regulation of energy balance. European Journal of Pharmacology, 440(2-3), pp.189-197.
  13. Qin, S., Hermans, E., van Marle, H., Luo, J. and Fernández, G., 2009. Acute Psychological Stress Reduces Working Memory-Related Activity in the Dorsolateral Prefrontal Cortex. Biological Psychiatry, 66(1), pp.25-32.
  14. Luethi, M., 2008. Stress effects on working memory, explicit memory, and implicit memory for neutral and emotional stimuli in healthy men. Frontiers in Behavioral Neuroscience, 2.
  15. Arnsten, A., 2009. Stress signalling pathways that impair prefrontal cortex structure and function. Nature Reviews Neuroscience, 10(6), pp.410-422.
  16. Adam, T. and Epel, E., 2007. Stress, eating and the reward system. Physiology & Behavior, 91(4), pp.449-458.
  17. Groesz, L., McCoy, S., Carl, J., Saslow, L., Stewart, J., Adler, N., Laraia, B. and Epel, E., 2012. What is eating you? Stress and the drive to eat. Appetite, 58(2), pp.717-721.
  18. Taheri, S., Lin, L., Austin, D., Young, T. and Mignot, E., 2004. Short Sleep Duration Is Associated with Reduced Leptin, Elevated Ghrelin, and Increased Body Mass Index. PLoS Medicine, 1(3), p.e62.
  19. Chaput, J., Després, J., Bouchard, C. and Tremblay, A., 2007. Short Sleep Duration is Associated with Reduced Leptin Levels and Increased Adiposity: Results from the Québec Family Study*. Obesity, 15(1), pp.253-261.
  20. Dashti, H., Scheer, F., Jacques, P., Lamon-Fava, S. and Ordovás, J., 2015. Short Sleep Duration and Dietary Intake: Epidemiologic Evidence, Mechanisms, and Health Implications. Advances in Nutrition, 6(6), pp.648-659.
  21. Landis, A., Parker, K. and Dunbar, S., 2009. Sleep, Hunger, Satiety, Food Cravings, and Caloric Intake in Adolescents. Journal of Nursing Scholarship, 41(2), pp.115-123.

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