Shift Work, Snacking and Insulin Resistance:

Snacks.  We all love them, especially in the wee hours of night shift, when exhaustion is at an all time high and we’re needing something to satisfy our hunger, or should I say cravings, to help keep us awake!

But is this the reason for our weight gain whilst working 24/7?

Well it would definitely be a contributing factor for many shift workers, particularly if these “snacks” are made up predominantly of trans fats, refined and processed carbohydrates as they are definitely not conducive to a healthy waistline.

When we’re sleep deprived, we also tend to crave the naughty stuff, the sweets and greasy chips because sleep deprivation impairs the frontal lobe region of the brain which oversees complex decision making, whilst at the same time, increasing activity in the deeper region of the brain called the amygdala, which is involved in reward seeking behaviour.

In other words, our tired brains are geared more to eating for pleasure, as opposed to hunger and explains why we’re more likely to crave the sweet and fatty foods.  Combine this with a disruption to our hunger hormones (as a result of a lack of sleep), which leads to an increase in appetite, its inevitable that weight gain will soon follow suit.

But what has this all got to do with insulin resistance?

Well each time we eat carbohydrates, it raises our blood sugar levels triggering the pancreas to release insulin, a hormone that prompts cells to absorb this blood sugar for energy or storage.

Insulin resistance is a condition where the body in unable to move this blood sugar from the blood, and into the cells efficiently.  This causes blood sugar levels to rise to unhealthy levels, which can lead to prediabetes and eventually type 2 diabetes.

Unfortunately for shift workers, sleep deprivation alone has shown to impair the way our body responds to insulin, so we’re disadvantaged before anything has even passed through our mouth!

However when we’re discussing insulin resistance, its not just about the food that we eat.

These days we tend to spend a lot of time obsessing about what we’re eating (I’m a Nutritionist, I totally get it), but we also need to be reviewing when we’re eating, along with the frequency of our food intake.

Because in the case of insulin resistance, it comes down to both meal composition AND meal timing.

In healthy individuals, each time we eat refined carbohydrates like sugar and white bread, it spikes our insulin levels, but then drops off soon after.  However, carbohydrates are not the only macronutrient to increase insulin levels.  Both protein and fats raise insulin levels, but to a much lesser extent.

So when we eat continually 24/7, with lots of snacks in between, it leads to persistently high levels of insulin which overtime, can develop into the condition of insulin resistance along with weight gain.  Figure 1 below shows a healthy fluctuation of insulin throughout the day, based on three meals a day, with dips between meals and when we’re sleeping.

Figure 1:  Insulin release with an eating pattern of three meals, no snacks.

In contrast, Figure 2 below, shows persistently high levels of insulin as a result of continually eating and snacking throughout the day (or night).  This ongoing level of raised insulin can eventually lead to insulin resistance (and weight gain).

Figure 2:  Insulin release with an eating pattern of multiple meals and snacks

Quite simply, figure 2 is not normal (or healthy).

As human beings, we haven’t evolved to eat continually 24/7, and probably never will.

So it’s time to pull back on the snacking – no matter what it is (remember all foods spike our insulin levels to some degree), so yes, this means even limiting consumption of those ‘healthy’ raw desserts too.

Now you may be asking, Audra, how am I going to keep my energy levels going whilst running on little sleep, if you won’t let me snack?

Here’s my top 3 tips for maintaining energy levels throughout our shifts:

1. Increase protein and healthy fats into your diet – in other words, you want to get more bang for your buck, each time you eat!  I’m sure we can all agree that we don’t always know when our next meal break is going to be, so its best to make the most of each one that comes along.  Foods rich in protein (such as grass-fed beef, organic chicken, free range eggs, lentils, Greek yoghurt) along with healthy fats (such as avocados, butter, coconut oil, nuts and seeds), all help to increase our satiety, or keep us feeling fuller for longer, so we’re less likely to want to snack continually throughout the day.
2. Include some moderate intensity exercise – studies on sleep deprived individuals have shown 10 minutes of walking up stairs to be more energising than consuming 50mg of caffeine (which is equivalent to a standard cup of coffee).
3. Increasing water intake – dehydration leads to fatigue, so maintaining hydration levels throughout the shift is an important strategy to assist in reducing the compounding effects of sleep deprivation.

Audra x

References:

Fung, J 2016, The Obesity Code:  Unlocking the Secrets of Weight Loss, Scribe Publications, Brunswick.

Greer, S, Goldstein, A & Walker, M 2013, ‘The impact of sleep deprivation on food desire in the human brain’, Nature Communications, vol. 4, no. 2259, pp. 1-19.

Harvard School of Public Health 2017, ‘Carbohydrates and Blood Sugar’.

Randolph, D & O’Connor, P 2017, ‘Stair walking is more energizing than low dose caffeine in sleep deprived young women’, Physiology & Behavior, vol. 174, pp. 128-135.

School of Medicine and Public Health 2013, ‘How the tired brain directs junk-food binges’, University of Wisconsin-Madison.