Blood Sugar & Mental Health

Most people know that blood sugar is important for physical health, but it also plays a role in how you feel and think. Research shows that high blood sugar (hyperglycemia) and big swings in blood sugar levels (glucose variability) can affect mental health—even in people who do not have diabetes.[1-16]

- Mood and Emotions: People with higher blood sugar or more ups and downs in their blood sugar are more likely to feel sad, anxious, or stressed. Those with the highest blood sugar swings have a greater risk of developing depression and anxiety, even if their levels are not high enough to be called diabetes.[1,2,4,7,10]

- Thinking and Memory: Frequent changes in blood sugar can make it harder to think clearly, remember things, and focus. This has been seen in people whose blood sugar is usually in the normal range but goes up and down a lot.[2,6,11,14]

- Long-Term Effects: Over many years, people with higher blood sugar or more swings are more likely to develop depression, anxiety, and stress-related disorders. These risks are seen in both men and women, and at all ages.[2,3,7]

- Quality of Life: Feeling down or anxious can make it harder to manage your health, which can lead to more blood sugar problems—a cycle that can be tough to break.[9,12,13]

Why does this happen?

The brain needs steady blood sugar to work well. When blood sugar is too high or changes a lot, it can cause stress and inflammation in the brain, which affects mood and thinking. Even if you do not have diabetes, keeping your blood sugar steady may help protect your mental health.[1-7,10,14]

What can you do to better manage your blood sugar?

1. Exercise after meals: 

Going for a walk or doing light activity after eating helps lower blood sugar spikes. This is true for people with and without diabetes. The sooner you move after a meal, the better the effect—try to walk for at least 15–30 minutes after eating.[13,17-21]

2. Limit snacking and try time-restricted feeding: 

Eating meals within a set window of time (for example, 8–10 hours each day) and avoiding late-night snacks can help keep blood sugar steady. Time-restricted eating (TRE) and limiting snacking have been shown to improve blood sugar control and may help with weight loss.[10,22-24] Pay attention to how long you go without eating. If you get shaky, irritable, or foggy, long fasting windows may not work for you.

NOTE: Fasting or TRE may not be appropriate for diabetics; always discuss with your medical provider, before considering dietary changes.

3. Decrease carbohydrates: 

Eating fewer foods high in sugar and starch (like white bread, rice, sweets, and sugary drinks) can help lower blood sugar. Focus on whole grains, vegetables, and fiber-rich foods. Low-carbohydrate diets can help with blood sugar control, but the best amount of carbs depends on your needs and what you can stick with long-term.[10,13,17,25-30]

4. Prioritize protein and healthy fats: 

Including more protein (like beans, fish, eggs, nuts, and lean meats) and healthy fats (like olive oil, nuts, and avocado) in your meals can help you feel full and keep blood sugar stable. Adding protein to meals with carbohydrates can lower blood sugar spikes, especially in people without diabetes.[10,31] Starting your day with protein + fiber can help keep your energy steady.

5. Other helpful habits: 

- Get enough sleep—poor sleep can make blood sugar harder to control.[19]

- Eat most of your calories earlier in the day and avoid large meals late at night.[26]

- Try to keep meal times consistent from day to day.

- If you notice changes in your mood, memory, or ability to focus, talk to your health care provider. These symptoms can have many causes, but blood sugar may be one of them.

The Bottom Line

Stable blood sugar doesn’t just influence physical health — it supports emotional stability, motivation, focus, and overall wellbeing.

Remember: 

You do not need to have diabetes for blood sugar to affect your mental health. Taking care of your body can help you feel better emotionally and mentally, too. If you have diabetes, working with your health care team to keep your blood sugar steady can help support your mental health. If you do not have diabetes, healthy habits and regular check-ups are still important for your mood and mind.[8,9,11,13,14]

Disclaimer:

This content is for informational purposes only. It is not intended to replace professional medical advice, diagnosis, or treatment from your healthcare provider. Always consult your physician or qualified health provider with any questions you may have regarding a medical condition. Use of this content does not establish a patient-provider relationship.

References

• Kim, H. J., Kim, S. M., Lee, G., et al. (2022). Association between visit-to-visit fasting glycemic variability and depression: A retrospective cohort study in a representative Korean population without diabetes. Scientific Reports, 12(1), 18692. doi:10.1038/s41598-022-22302-0

  
  

• Chourpiliadis, C., Zeng, Y., Lovik, A., et al. (2024). Metabolic profile and long-term risk of depression, anxiety, and stress-related disorders. JAMA Network Open, 7(4), e244525. doi:10.1001/jamanetworkopen.2024.4525

  
  

• Geraets, A. F. J., Köhler, S., Muzambi, R., et al. (2020). The association of hyperglycaemia and insulin resistance with incident depressive symptoms over 4 years of follow-up: The Maastricht Study. Diabetologia, 63(11), 2315–2328. doi:10.1007/s00125-020-05247-9

  
  

• Mishra, S., Singh, A. K., Rajotiya, S., et al. (2023). Exploring the risk of glycemic variability in non-diabetic depressive individuals: A cross-sectional GlyDep pilot study. Frontiers in Psychiatry, 14, 1196866. doi:10.3389/fpsyt.2023.1196866

  
  

• Gudonytė, J., Žukauskaitė, I., & Norkus, A. (2025). Linking glucose swings and mental health to cardiovascular outcomes and mortality in general practice. Scientific Reports, 15(1), 39045. doi:10.1038/s41598-025-26281-w

  
  

• Bancks, M. P., Carnethon, M. R., Jacobs, D. R., et al. (2018). Fasting glucose variability in young adulthood and cognitive function in middle age: The CARDIA study. Diabetes Care, 41(12), 2579–2585. doi:10.2337/dc18-1287

  
  

• Watt, C., Sanchez-Rangel, E., & Hwang, J. J. (2020). Glycemic variability and CNS inflammation: Reviewing the connection. Nutrients, 12(12), 3906. doi:10.3390/nu12123906

  
  

• Wolf, T., Tsenkova, V., Ryff, C. D., Davidson, R. J., & Willette, A. A. (2018). Neural, hormonal, and cognitive correlates of metabolic dysfunction and emotional reactivity. Psychosomatic Medicine, 80(5), 452–459. doi:10.1097/PSY.0000000000000582

  
  

• Kwon, M., Lee, M., Kim, E. H., et al. (2023). Risk of depression and anxiety disorders according to long-term glycemic variability. Journal of Affective Disorders, 343, 50–58. doi:10.1016/j.jad.2023.09.017

  
  

• American Diabetes Association. (2025). Facilitating positive health behaviors and well-being to improve health outcomes. Diabetes Care, 48(Suppl. 1), S86–S127. doi:10.2337/dc25-S005

  
  

• Tenreiro, K., & Hatipoglu, B. (2025). Mind matters: Mental health and diabetes management. The Journal of Clinical Endocrinology & Metabolism, 110(Suppl. 2), S131–S136. doi:10.1210/clinem/dgae607

  
  

• Chamseddine, Z. M., Nasrallah, M. P., Tamim, H., Nasreddine, L., & Elbejjani, M. (2024). Glycemic indicators and mental health symptoms: Results from the Greater Beirut Area Cardiovascular Cohort. Frontiers in Endocrinology, 15, 1347092. doi:10.3389/fendo.2024.1347092

  
  

• Davies, M. J., Aroda, V. R., Collins, B. S., et al. (2022). Management of hyperglycemia in type 2 diabetes: 2022 consensus report by the ADA and the EASD. Diabetes Care, 45(11), 2753–2786. doi:10.2337/dci22-0034

  
  

• Penckofer, S., Quinn, L., Byrn, M., et al. (2012). Does glycemic variability impact mood and quality of life? Diabetes Technology & Therapeutics, 14(4), 303–310. doi:10.1089/dia.2011.0191

  
  

• Chung, W. K., Erion, K., Florez, J. C., et al. (2020). Precision medicine in diabetes: ADA/EASD consensus report. Diabetes Care, 43(7), 1617–1635. doi:10.2337/dci20-0022

  
  

• American Diabetes Association. (2025). Comprehensive medical evaluation and assessment of comorbidities. Diabetes Care, 48(Suppl. 1), S59–S85. doi:10.2337/dc25-S004

  
  

• Kanaley, J. A., Colberg, S. R., Corcoran, M. H., et al. (2022). Exercise/physical activity in individuals with type 2 diabetes: Consensus statement from the ACSM. Medicine & Science in Sports & Exercise, 54(2), 353–368. doi:10.1249/MSS.0000000000002800

  
  

• Gillen, J. B., Estafanos, S., & Govette, A. (2021). Exercise-nutrient interactions for improved postprandial glycemic control and insulin sensitivity. Applied Physiology, Nutrition, and Metabolism, 46(8), 856–865. doi:10.1139/apnm-2021-0168

  
  

• Yao, J., Brugger, V. K., Edney, S. M., et al. (2024). Diet, physical activity, and sleep in relation to postprandial glucose responses under free-living conditions. International Journal of Behavioral Nutrition and Physical Activity, 21(1), 142. doi:10.1186/s12966-024-01693-5

  
  

• Engeroff, T., Groneberg, D. A., & Wilke, J. (2023). Acute postprandial glycemic response to exercise before/after meals: Systematic review and meta-analysis. Sports Medicine, 53(4), 849–869. doi:10.1007/s40279-022-01808-7

  
  

• Kang, J., Fardman, B. M., Ratamess, N. A., Faigenbaum, A. D., & Bush, J. A. (2023). Efficacy of postprandial exercise in mitigating glycemic responses in overweight/obese adults and individuals with type 2 diabetes: Systematic review and meta-analysis. Nutrients, 15(20), 4489. doi:10.3390/nu15204489

  
  

• Nam, T., Oh, H., Kim, A., & Oh, Y. (2025). Time-restricted eating improves glycemic control in type 2 diabetes: Systematic review and meta-analysis. International Journal of Molecular Sciences, 26(15), 7310. doi:10.3390/ijms26157310

  
  

• Cienfuegos, S., McStay, M., Gabel, K., & Varady, K. A. (2022). Time-restricted eating for prevention of type 2 diabetes. The Journal of Physiology, 600(5), 1253–1264. doi:10.1113/JP281101

  
  

• Tsitsou, S., Zacharodimos, N., Poulia, K. A., et al. (2022). Effects of time-restricted feeding and Ramadan fasting on weight, body composition, glucose responses, and insulin resistance: Systematic review of RCTs. Nutrients, 14(22), 4778. doi:10.3390/nu14224778

  
  

• Ahmad, E., Lim, S., Lamptey, R., Webb, D. R., & Davies, M. J. (2022). Type 2 diabetes. The Lancet, 400(10365), 1803–1820. doi:10.1016/S0140-6736(22)01655-5

  
  

• Papakonstantinou, E., Oikonomou, C., Nychas, G., & Dimitriadis, G. D. (2022). Effects of diet, lifestyle, chrononutrition, and alternative dietary interventions on postprandial glycemia and insulin resistance. Nutrients, 14(4), 823. doi:10.3390/nu14040823

  
  

• Astbury, N. M. (2024). Interventions to improve glycaemic control in people living with and at risk of type 2 diabetes. Diabetes, Obesity & Metabolism, 26(Suppl. 4), 39–49. doi:10.1111/dom.15855

  
  

• Blonde, L., Umpierrez, G. E., Reddy, S. S., et al. (2022). AACE clinical practice guideline: Developing a diabetes mellitus comprehensive care plan—2022 update. Endocrine Practice, 28(10), 923–1049. doi:10.1016/j.eprac.2022.08.002

  
  

• Janssen-Aguilar, R., Vije, T., Peera, M., et al. (2025). Ketogenic diets and depression and anxiety. JAMA Psychiatry, Advance online publication. doi:10.1001/jamapsychiatry.2025.3261

  
  

• Sindler, D., Kastovska, B., Dostal, T., Cipryan, L., & Elavsky, S. (2024). Effects of carbohydrate-restricted diets on psychological outcomes: Systematic review of randomized controlled trials. Nutrition Reviews, 82(2), 228–239. doi:10.1093/nutrit/nuad053

  
  

• Wolever, T. M., Zurbau, A., Koecher, K., & Au-Yeung, F. (2024). Effect of adding protein to a carbohydrate meal on postprandial glucose and insulin responses: Systematic review and meta-analysis. The Journal of Nutrition, 154(9), 2640–2654. doi:10.1016/j.tjnut.2024.07.011