I’m all too familiar with that 7-a.m. feeling following 3 night shifts in a row with only fractured and fitful rest in the days between. I’m in a mental haze, able to take in little and process even less. The world gradually slips away and the only thing I can focus on is the malaise that has overtaken my body. Every muscle aches, begging for rest and a return to a normal circadian rhythm.
I’ve worked nights both as a CNA at a hospital as well as a military service member at tactical operations centers or guard posts. Currently, I’m a dietitian. While I don’t work nights anymore, there are some key dietary strategies I wish I would have known and implemented when I was a shift worker.
It may seem obvious, but stick with me. Obesity, cardiovascular disease, and diabetes are more prevalent among night or mixed shift workers than among day shift workers. In a large population of nurses spanning 25 years, researchers estimated that an unhealthy diet was responsible for nearly 75% of all diabetes cases. About 10% of the cases, however, were attributed to an interaction between night shift work and lifestyle. Translation: it’s especially important for shift workers to eat healthily. The combination of an unhealthy diet and shift work puts you at a greater risk for disease than an unhealthy diet alone.
Shift work may disrupt the ratio of healthy to unhealthy bacteria in your digestive system, potentially increasing your risk of diabetes and heart disease. Although more research is required to determine what role, if any, probiotics have in improving health outcomes among shift workers, prebiotics and probiotics are generally regarded as a healthy addition to most diets.
Shift work causes circadian misalignment, a condition where your body behaves hormonally and metabolically like you’re asleep during normal sleeping hours even though you’re awake. Studies show that late-night meals among shift workers result in elevated blood triglyceride and glucose levels as well as reduced insulin sensitivity, a metabolic state similar to diabetes. Nighttime eating is thought to, at least partly, explain why many night shift workers have a harder time maintaining a healthy weight despite consuming a similar number of calories as counterparts working a day shift. Animal studies provide further evidence that nighttime eating may directly lead to obesity.
Mental and physical fatigue is suspected to contribute to an increase in worker injuries and error during night shifts. Larger or high-fat meals may further increase feelings of fatigue, especially after periods of poor sleep. Be especially vigilant on the meal immediately before your shift and any meals you eat during your shift as these are the meals most likely to lead to fatigue.
This is the first part of our series on dietary strategies for shift workers. Stay on the lookout for part two, where we’ll dive into the science behind herbal supplements and stimulants commonly used to promote alertness in shift work.
1. Sun M, Feng W, Wang F, Li P, Li Z, Li M, Tse G, Vlaanderen J, Vermeulen R, Tse LA. Meta-analysis on shift work and risks of specific obesity types. Obes Rev. 2018 Jan;19(1):28-40. doi: 10.1111/obr.12621.
2. Vyas MV, Garg AX, Iansavichus AV, Costella J, Donner A, Laugsand LE, Janszky I, Mrkobrada M, Parraga G, Hackam DG. Shift work and vascular events: systematic review and meta-analysis. BMJ. 2012 Jul 26;345:e4800. doi: 10.1136/bmj.e4800.
3. Li W, Chen Z, Ruan W, Yi G, Wang D, Lu Z. A meta-analysis of cohort studies including dose-response relationship between shift work and the risk of diabetes mellitus. Eur J Epidemiol. 2019 Nov;34(11):1013-1024. doi: 10.1007/s10654-019-00561-y.
4. Shan Z, Li Y, Zong G, Guo Y, Li J, Manson JE, Hu FB, Willett WC, Schernhammer ES, Bhupathiraju SN. Rotating night shift work and adherence to unhealthy lifestyle in predicting risk of type 2 diabetes: results from two large US cohorts of female nurses. BMJ. 2018 Nov 21;363:k4641. doi: 10.1136/bmj.k4641.
5. U.S. Department of Health and Human Services and U.S. Department of Agriculture. 2015 – 2020 Dietary Guidelines for Americans. 8th Edition. December 2015. Available at https://health.gov/dietaryguidelines/2015/guidelines/.
6. Reynolds AC, Paterson JL, Ferguson SA, Stanley D, Wright KP Jr, Dawson D. The shift work and health research agenda: Considering changes in gut microbiota as a pathway linking shift work, sleep loss and circadian misalignment, and metabolic disease. Sleep Med Rev. 2017 Aug;34:3-9. doi: 10.1016/j.smrv.2016.06.009.
7. Al-Naimi S, Hampton SM, Richard P, et al. Postprandial metabolic profiles following meals and snacks eaten during simulated night and day shift work. Chronobiol Int. 2004;21:937–47. doi:10.1081/CBI-200037171
8. Grant CL, Coates AM, Dorrian J, et al. Timing of food intake during simulated night shift impacts glucose metabolism: A controlled study. Chronobiol Int. 2017;34:1003–13. doi: 10.1080/07420528.2017.1335318
9. Bonham MP, Bonnell EK, Huggins CE. Energy intake of shift workers compared to fixed day workers: a systematic review and meta-analysis. Chronobiol Int. 2016;33:1086–100. doi: 10.1080/07420528.2016.1192188
10. Arble DM, Bass J, Laposky AD, et al. Circadian timing of food intake contributes to weight gain. Obesity. 2009;17:2100–2. doi: 10.1038/oby.2009.264
11. Hanlon EC, Tasali E, Leproult R, Stuhr KL, Doncheck E, de Wit H, Hillard CJ, Van Cauter E. Sleep Restriction Enhances the Daily Rhythm of Circulating Levels of Endocannabinoid 2-Arachidonoylglycerol. Sleep. 2016 Mar 1;39(3):653-64. doi: 10.5665/sleep.5546.
12. Folkard S, Lombardi DA. Modeling the impact of the components of long work hours on injuries and “accidents”. Am J Ind Med. 2006 Nov;49(11):953-63.
13. TY – Reyner LA, Wells SJ, MOrtlock V, Horne JA. ‘Post-lunch’ sleepiness during prolonged, monotonous driving – effects of meal size. Physiol Behav. 2011 Dec;105(4):1088-91. doi: 10.1016/j.physbeh.2011.11.025
14. Wells AS, Read NW, Craig A. Influences of dietary and intraduodenal lipid on alertness, mood, and sustained concentration. Br J Nutr. 1995 Jul;74(1):115-23.
Ron is a registered dietitian, exercise physiologist, and writer. As a retail dietitian, Ron advises on and writes about the latest food trends and products and has been featured on numerous local news outlets. Ron has worked in various settings as a health professional including hospitals, corporate wellness, and nutritional supplement R&D. Ron is also a member of the Utah National Guard where he serves as an operations officer.