Guest post written by Chiara Toscano, recent Dietetics Graduate from the University of Ottawa, and Miriam Bendayan, Dietetics Student from the University of Ottawa, edited by Jennifer Neale, Registered Dietitian and Certified Intuitive Eating Counsellor.
In our first post, we broke down what cortisol actually is, what it does in the body, whether you should be worried about high cortisol levels, and why its connection to stress is often misunderstood online. We also talked about true cortisol disorders, such as Cushing’s and Addison’s disease; How they are uncommon and require proper medical testing and management.
If you haven’t read it yet, you can start here.
So where do food and lifestyle fit into the picture?
Since high cortisol is closely tied to stress, it’s completely reasonable to wonder whether what we eat can affect cortisol levels and whether cortisol can influence how we eat.
The answer to both is yes, but probably not in the way TikTok or Instagram suggests.
In Post 1, we discussed how cortisol increases when stress is high. The brain tells the body to release cortisol → the cortisol increases the amount of sugar in our bloodstream so that it can travel to the brain → the brain uses that additional sugar as fuel to help it think and move to respond to the stress.
This means that when you’re stressed, your body uses more energy and burns through certain nutrients faster. Stress is metabolically demanding, and some research suggests it’s linked to lower levels of minerals like magnesium, zinc, iron, and calcium. What we don’t really know yet is whether taking supplements actually fixes this or if stress itself is the main issue.
This is where the internet tends to oversimplify things. You’ve probably seen “cortisol mocktails” on social media, drinks with lemon, ginger, cinnamon, or orange juice that claim to lower cortisol. The truth is, there’s no solid evidence that a single drink can meaningfully change your stress hormones. These ingredients aren’t bad, and staying hydrated or taking a moment to slow down can help you feel better, but that’s not the same thing as lowering your cortisol.
If you like the taste of a cortisol mocktail, by all means, go for it. Just don’t expect it to fix your hormones. The same goes for expensive supplements marketed as “cortisol-lowering.” Nutrition matters, but there’s no magic pill, and no magic drink either, to reduce your stress and thus reduce your cortisol.
Carbohydrates get blamed for a lot online, including high cortisol levels, but research doesn’t really support that idea. In fact, very low-carbohydrate diets can temporarily increase cortisol levels. From a physiology standpoint, that makes sense. When the body is under-fueled, it experiences that as a form of stress. The brain is fueled by carbohydrates. If you are eating a low-carbohydrate diet, the brain still needs fuel, so it will release cortisol to help increase the amount of sugar getting to the brain so that you can still do the things you need to do in your day.
The same idea applies to time-restricted eating or intermittent fasting. These approaches may work well for some people, but for others, it adds more stress, both mentally and physically. Ignoring hunger cues, feeling pressure to eat “perfectly,” or consistently under-eating can all work against healthy stress hormone regulation. If a way of eating feels stressful, it probably isn’t helping your cortisol, even if it’s popular online.
Instead of chasing “cortisol-lowering” foods or supplements, it’s more helpful to focus on simple nutrition habits that support energy and reduce physiological stress. Eating enough is a big one. Chronic under-eating is stressful to your body and can increase cortisol levels. Adequately fueling your body helps signal safety rather than stress. Remember that your body’s job is to keep you alive; it really hates to be starved.
Fibre also fits into this picture. Some research suggests fibre may support healthy cortisol levels through its effects on the gut. When we eat fibre, gut bacteria ferment it and produce short-chain fatty acids (SCFAs), which provide energy and support overall health. More fibre means more SCFAs, which means better energy availability for the body.
Does that mean you need a fibre supplement to help manage cortisol levels? Probably not. Eating a diet that contains an adequate amount of high-fibre grains, starches, fruits and vegetables should be enough to give your body the carbohydrates and fibre that it needs.
Taken together, the goal isn’t to micromanage cortisol through rigid rules or restriction. It’s about nourishing your body in a way that feels supportive, adequate, and sustainable. When nutrition helps reduce stress instead of adding to it, it’s far more likely to promote balanced cortisol levels over time.
Of course, getting there is often easier said than done. If you find yourself caught up in diet culture or struggling to move away from restrictive habits, extra support can make all the difference. A dietitian can help you untangle which behaviours are no longer serving you and which ones are genuinely supporting your health, so you can build habits that feel both nourishing and realistic. If you’re in Ontario and looking for support from a Registered Dietitian to navigate stress, eating, and cortisol concerns without restriction, you can book a free call here.
Short answer: Yes, it can.
Research suggests cortisol influences how much we eat by acting on the brain’s reward system and interacting with appetite-regulating hormones such as leptin and insulin. Higher stress and higher cortisol levels have been linked to a stronger drive to eat, particularly foods higher in sugar and fat, aka the classic “comfort foods.”
This increased desire to eat when stressed has also been seen in children. Higher long-term stress and cortisol levels are associated with greater intake of sweet and high-fat snack foods, as well as more difficulty eating mindfully. While research on mindfulness, cortisol, and eating is still limited, early studies suggest mindfulness-based approaches may help improve stress levels and eating patterns.
Physiologically, this all makes sense. Cortisol increases energy needs and increases the availability of glucose (sugar) to the brain, so cravings for quick energy (like those high in sugar) or energy-dense foods (like those that are high in fat) aren’t a lack of willpower; they’re a biological survival mechanism that evolved with us over thousands of years.
If you’re curious about the science behind emotional eating, why it happens, and how to deal with it, we have a full blog post dedicated to that topic! You can read about that here.
There has been talk on social media that you should avoid certain types of exercise because they increase cortisol levels. But should you?
Exercise, specifically high-intensity interval training (often abbreviated to HIIT), does temporarily raise cortisol, and that’s normal. Your body needs energy to move, and cortisol helps make that energy available.
Does that mean that you should avoid HIIT? No. Once your training session is over, your cortisol levels return to normal because you no longer need the extra energy for your brain and muscles. This is part of cortisol’s normal daily rhythm. It rises when it’s needed and falls when it’s not.
The good news is that regular movement is associated with lower baseline cortisol levels over time. We know that regular activity can actually reduce overall stress and increase mood (thank you endorphins). Therefore, moving your body consistently can help your stress response become more resilient.
The best kind of exercise for keeping cortisol levels low isn’t a specific workout or intensity level. It’s simply doing the kind of movement you enjoy enough to keep doing, without it becoming another source of stress.
If you hate the movement that you’re doing, or if it’s causing you stress, then change it. Experiment and try new things until you find something that you enjoy. Enjoyable movement is a lot more sustainable than forcing yourself to engage in movement that you hate.
Sleep and stress have a two-way relationship. Poor sleep can increase stress, and stress can make it harder to sleep. It is a vicious cycle!
Instead of trying to “optimize” cortisol levels through rigid routines, focusing on the basics like consistent sleep schedules, putting your phone down an hour before you’re planning to go to sleep, regular movement, and stress reduction is often far more effective and much less exhausting.
Small, realistic changes matter more than perfect habits.
Cortisol isn’t the enemy. It’s a necessary hormone that helps your body function, adapt, and survive.
While nutrition, sleep, movement, and stress management all play a role in supporting healthy cortisol patterns, extreme diets, restriction, and fear-based wellness trends often do more harm than good.
The take-home message that keeps coming up is to ditch the all-or-nothing mindset!
Reducing your cortisol levels naturally isn’t about doing more, adding more to your routine, restricting yourself, or spending money on expensive supplements and cortisol cocktails. It’s about doing less.
I know that it seems counter-intuitive and we always feel like we should be doing something to optimize our health. BUT nourishing your body consistently, eating enough, moving in ways you enjoy, prioritizing rest, and reducing stress where you can, all support your body’s natural ability to regulate cortisol.
If you want help navigating nutrition without restriction or cortisol panic, working with a Registered Dietitian can help take the stress out of food. And sometimes, lowering stress around food is one of the most powerful things you can do for your health.
Need a quick summary of this blog post (or maybe you skipped to the bottom…no judgment), here are 6 commonly asked questions about lowering cholesterol with food, exercise, and sleep.
Cortisol is supposed to fluctuate during the day. Healthy cortisol regulation is supported by getting enough sleep, eating enough food, engaging in regular movement that you enjoy, and managing your stress. Extreme diets, supplements, or “cortisol mocktails” are unlikely to meaningfully change cortisol levels in otherwise healthy individuals.
There is currently no strong scientific evidence that a specific drink can significantly lower cortisol levels. While hydration and slowing down may help you feel calmer, they do not directly “fix” stress hormones. If you like them and they make you feel good, go for it, but they are unlikely to have any impact.
I think social media misinterprets what is actually happening when blood sugar is high while cortisol is high. Eating sugar does not increase your cortisol. Cortisol increases the amount of sugar in the blood to create fuel for your brain.
In addition to this, eating a very low-carbohydrate diet can actually increase cortisol because the body interprets under-fueling as stress. Eating adequate carbohydrates helps provide energy to the brain and may reduce physiological stress.
Intermittent fasting can be stressful for some individuals, especially if it leads to under-eating or ignoring hunger cues. When the body experiences restriction as stress, cortisol levels may rise.
All exercise temporarily increases cortisol during the workout. However, regular enjoyable movement is associated with lower baseline stress levels over time. The best exercise for cortisol regulation is one you can do consistently without it becoming another source of stress.
Cortisol follows a natural daily rhythm, rising in the morning and falling at night. Poor sleep can disrupt this rhythm and increase stress. Consistent sleep habits support healthier cortisol patterns.
At the end of the day, micromanaging your cortisol levels is likely to cause more stress and thus increase cortisol rather than lower it. The most helpful way to manage high cortisol naturally is to reduce your stress, eat a balanced diet, move your body, and get enough sleep. Yes, I know that is completely unsexy advice, but sometimes simple is best. If a wellness influencer is trying to sell you their “proven” supplement, drink, or miracle cure, I would be highly skeptical of the “proof” they have gathered.
Allen, M. J., & Sharma, S. (2019, March 3). Physiology, adrenocorticotropic hormone (ACTH). StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK500031/
Burek, K., Rabstein, S., Kantermann, T., Vetter, C., Wang-Sattler, R., Lehnert, M., Pallapies, D., Jöckel, K.-H., Brüning, T., & Behrens, T. (2024). Altered coordination between sleep timing and cortisol profiles in night working female hospital employees. Psychoneuroendocrinology, 166, 107066. https://doi.org/10.1016/j.psyneuen.2024.107066
Chen, Y., Xu, W., Chen, Y., Gong, J., Wu, Y., Chen, S., He, Y., Yu, H., & Xie, L. (2024). The effect of acute sleep deprivation on cortisol level: A systematic review and meta-analysis. Endocrine Journal, 71(8), 753–765. https://doi.org/10.1507/endocrj.ej23-0714
Cole, J. L. (2020). Steroid-induced sleep disturbance and delirium: A focused review for critically ill patients. Federal Practitioner, 37(6), 260–267. https://doi.org/10.12788/fp.003
Hirotsu, C., Tufik, S., & Andersen, M. L. (2015). Interactions between sleep, stress, and metabolism: From physiological to pathological conditions. Sleep Science, 8(3), 143–152. https://doi.org/10.1016/j.slsci.2015.09.002
Kairys, N., & Schwell, A. (2020). Cushing disease. StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK448184/
LeWine, H. (2024, April 3). Understanding the stress response. Harvard Health Publishing. https://www.health.harvard.edu/staying-healthy/understanding-the-stress-response
Lightman, S. L., Birnie, M. T., & Conway-Campbell, B. L. (2020). Dynamics of ACTH and cortisol secretion and implications for disease. Endocrine Reviews, 41(3), 470–490. https://doi.org/10.1210/endrev/bnaa002
Moeller, S. J., Couto, L., Cohen, V., Lalazar, Y., Makotkine, I., Williams, N., Yehuda, R., Goldstein, R. Z., & Geer, E. B. (2016). Glucocorticoid regulation of food-choice behavior in humans: Evidence from Cushing’s syndrome. Frontiers in Neuroscience, 10, Article 21. https://doi.org/10.3389/fnins.2016.00021
Munir, S., & Waseem, M. (2024). Addison disease. StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK441994/
Nicolaides, N. C., Vgontzas, A. N., Kritikou, I., & Chrousos, G. (2020). HPA axis and sleep. In K. R. Feingold et al. (Eds.), Endotext. MDText.com, Inc. https://www.ncbi.nlm.nih.gov/books/NBK279071/
Sarnes, E., Crofford, L., Watson, M., Dennis, G., Kan, H., & Bass, D. (2011). Incidence and US costs of corticosteroid-associated adverse events: A systematic literature review. Clinical Therapeutics, 33(10), 1413–1432. https://doi.org/10.1016/j.clinthera.2011.09.009
Steiger, A. (2007). Neurochemical regulation of sleep. Journal of Psychiatric Research, 41(7), 537–552. https://doi.org/10.1016/j.jpsychires.2006.04.007
Thau, L., Gandhi, J., & Sharma, S. (2023, August 28). Physiology, cortisol. StatPearls. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK538239/
Walvekar, S. S. (2015). Study on serum cortisol and perceived stress scale in police constables. Journal of Clinical and Diagnostic Research. https://doi.org/10.7860/jcdr/2015/12015.5576
Wright, K. P., Drake, A. L., Frey, D. J., Fleshner, M., Desouza, C. A., Gronfier, C., & Czeisler, C. A. (2015). Influence of sleep deprivation and circadian misalignment on cortisol, inflammatory markers, and cytokine balance. Brain, Behavior, and Immunity, 47, 24–34. https://doi.org/10.1016/j.bbi.2015.01.004
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