Welcome to Focus on Fatigue!
After a bad night’s sleep, getting out of bed in the morning can be a real challenge. Many of us know well the experience of stumbling into the kitchen in search of the world’s biggest cup of coffee. Fast forward to morning tea and we might find ourselves shunning the healthy snack we know we should eat in favour of something that’s either covered with sugar or laden with saturated fat, preferably both. In truth, these cravings for high-calorie goodness when we’re overtired is just one of the ways our bodies deal with sleep deprivation. Unfortunately, knowing this won’t make the cravings go away.
In this issue of Focus on Fatigue, we’ll investigate the relationship between sleep and nutrition, and some of the ways in which they affect each other.
The FRMS Team
InterDynamics Pty Ltd
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Views expressed in articles and links provided are those of the individual authors, and do not necessarily represent the views of InterDynamics (except where directly attributed).
Feeding the Need to Sleep
Most adults struggle, at times, with eating a healthy diet. With so many demands on our time, including work, family, community activities and having a social life, sometimes a healthy diet slips further down the priority list than we would like.
For shift workers, this struggle can be intensified, especially when eating ‘lunch’ in the middle of the night becomes a regular occurrence. Part of the difficulty experienced by shift workers who are attempting to stick to a healthy diet, stems from the way in which nutrition and sleep affect each other.
Sleep length affects nutrition
In 2012, a group of researchers examined the sleep and weight data for 21,469 individuals of 20 years or more who underwent health check-ups in an international hospital between 2005 and 2008. They found that individuals who slept for 5 hours or less were significantly more likely to experience weight gain or become obese. This was true even after other influences, such as gender and level of physical activity, were accounted for.
Why would this be the case? Sleep deprivation has been found to lead to increased caloric intake, increased portion sizes, increased fat consumption, and greater impulsiveness in response to food cues. These changes in behaviour are driven by changes to brain chemistry and brain activity that are triggered by sleep deprivation.
A number of studies have found an increase in food intake among otherwise healthy men after just one night of restricted sleep. This increased food intake is not generally accompanied by an increase in energy expenditure which, if it occurred, would help to counteract the extra calories.
It should be noted that much of the research in this area has involved short-term studies, conducted over just a few days. There is certainly not enough longitudinal data to support the notation that anyone who is deprived of sleep on a regular basis is destined to gain weight or become obese. In fact, reviews of the long-term studies that are available have found that the results vary considerably. However, it is important to consider the influence that sleep deprivation may have on the dietary choices of shift workers.
Nutrition affects sleep length
People have searched long and far for foods that will help them sleep. Who hasn’t tried drinking a cup of warm milk when they can’t sleep? This search has yielded some potentially useful results. For instance:
- The research suggests that eating within the hour before bed, especially food that is high in fat or carbohydrates, results in lower sleep quality. For example, people who opt for this kind of late-night snack tend to take longer to get to sleep, have lighter, less restorative sleep, and wake up more often during the night.
- One study found the consumption of tart cherry juice (which is rich in the sleep-promoting chemical melatonin) led to improved sleep duration and quality in healthy men and women.
- In another, total sleep time and efficiency were significantly increased when participants ate two kiwifruits an hour before bed every day for four weeks.
- In one review of studies examining the link between food and sleep quality, one group of researchers found that foods impacting the availability of tryptophan (such as poultry and dairy) may be helpful in promoting sleep.
However, this does not mean that people suffering insomnia should run to the shops to stock up on cherry juice, kiwifruit and turkey. At least, not just yet.
While researchers are still actively investigating what types of food will make a person sleep better, this area of science is still young and no firm conclusions have yet been drawn. For example, some experts in the area believe the amount of poultry (e.g. turkey or chicken) you would need to consume before the tryptophan inside would have a noticeable affect on your sleep is unreasonably high and therefore eating foods high in tryptophan as a means of feeling sleepy is simply not practical.
In the meantime, it may be useful for individuals to experiment with different types and amounts of healthy pre-sleep snacks to see what works for them.
- Brondel, L., Romer, M. A., Nougues, P. M., Touyarow, P. and Davenne, D. (2010) Acute partial sleep deprivation increases food intake in healthy men. The American Journal of Clinical Nutrition, 91, 1550-1559.
Crispim, C. A., Zimberg, I. Z., dos Reis, B. G., Diniz, R. M., Tufik, S. and de Mello, M. T. (2011) Relationship between food intake and sleep pattern in healthy individuals. Journal of Clinic Sleep Medicine, 7(6), 659-664.
- Fang, Z., Spaeth, A. M., Ma, N., Shu, S., Hu, S., Goel, N., Detre, J. A., Dinges, D. F. and Rao, H. (2015) Altered salience network connectivity predicts macronutrient intake after sleep deprivation. Scientific Reports, 5, 8215; DOI:10.1038/srep08215.
- Greer, S. M., Goldstein, A. N. and Walker, M. P. (2013) The impact of sleep deprivation on food desire in the human brain. Nature Communications, 6(4), 2259.
- Howatson, G., Bell, P. G., Tallent, J., Middleton, B., McHugh, M. P. and Ellis, J. (2012) Effect of tart cherry juice (Prunus cerasus) on melatonin levels and enhanced sleep quality. European Journal of Nutrition, 51(8), 909-916.
- Kobayashi, D., Takahashi, O., Deshpande, G. A., Shimbo, T. and Fukui, T. (2012) Association between weight gain, obesity, and sleep duration: A large-scale 3-year cohort study. Sleep and Breathing, 16(3), 829-833.
- Lin, H. H., Tsai, P. S., Fang, S. C. and Liu, J. F. (2011) Effect of kiwifruit consumption on sleep quality in adults with sleep problems. Asia Pacific Journal of Clinical Nutrition, 20(2), 169-174.
- Magee, L. and Hale, L. (2012) Longitudinal associations between sleep duration and subsequent weight gain: A systematic review. Sleep Medicine Reviews, 16(5), 491.
- Marshall, N. S., Glozier, N. and Grunstein, R. R. (2008) Is sleep duration related to obesity? A critical review of the epidemiological evidence. Sleep Medicine Reviews, 12, 289-298.
- Peuhkuri, K., Sihvola, N. and Korpela, R. (2012) Diet promotes sleep duration and quality. Nutrition Research, 32(5), 309-319.
- St-Onge, M.-P. (2016) Fiber and saturated fat are associated with sleep arousals and slow wave sleep. Journal of Clinical Sleep Medicine, 12(1), 19-24.
- St-Onge, M.-P., Roberts, A. L., Chen, J., Kelleman, M., O’Keeffe, M., RoyChoudhury, A. and Jones, P. J. H. (2011) Short sleep duration increases energy intakes but does not change energy expenditure in normal-weight individuals. The American Journal of Clinical Nutrition, 94, 410-416.
Congratulations to Fonterra
Fonterra Wins Top National Health and Safety Award
Diary giant, Fonterra Co-operative Limited, recently won three awards at the New Zealand Workplace Health and Safety Awards. These included the Supreme Award for the Best Overall Contribution to Improving Workplace Health and Safety in New Zealand and an award for the Best Initiative to Address a Safety Risk.
Fonterra currently uses FAID, an InterDynamics product, to assist them in monitoring tank driver fatigue. Here at InterDynamics, we would like to congratulate Fonterra for these outstanding achievements in the area of workplace health and safety.
You can read more about Fonterra’s achievements at their website.
In the News
Sleep deprivation is on a long list of risk factors for obesity, but how, exactly, does insufficient sleep fuel weight gain? A new study published in SLEEP suggests the answer lies within the endocannabinoid (eCB) system.
Article: High-Fat Diet May Short-Circuit Circadian Rhythm, Disrupting Sleep Cycle And Causing Drowsiness
Daytime sleepiness is dangerous. It causes everything from car accidents to poor cognitive performance and affects roughly 20 percent of the American adult population. Hoping to find out what’s making us so sleepy, Australian researchers from the University of Adelaide took a look at the complex anatomy of appetite and diet. Their findings, published in the journal Nutrients, show how a high-fat diet plays a role in daytime sleepiness.