Do you know somebody who does shift work? Maybe a nurse, firefighter, emergency physician, police officer, or someone else?

Well, this might be one of the most useful articles that they’ll ever read.

Since my team of personal trainers works a lot with both nurses and firefighters, we frequently get asked about the relationship between shift work and health. But even more importantly, what can be done about it.

Yes, research is fairly conclusive that shift work is associated with:

  • Heart disease
  • Cancer
  • Diabetes
  • Digestive disorders
  • Depression

… and more.

However, given that we are personal trainers, and most people come to us for help with weight loss, toning, and more energy, I’ll only focus on that side of things in regards to shift work.

And hey, if you want to skip all the information in this article, and get personalized help, you can fill out this questionnaire to see if you qualify to work with us.

Original source: here.

The Eating Habits of Shift Workers

When discussing the association between shift work and health, no discussion would be complete without a discussion of eating habits.

Do shift workers eat differently, compared to the rest of us? Many studies say “yes.”

For example, one study found that shift workers eat approximately 60 more calories per day, as well as more carbohydrates and fats, and less protein. Sixty calories per day isn’t much, but over time, it certainly adds up, especially combined with the hormonal profile of shift workers (which will be discussed later).

Although research isn’t conclusive that shift workers eat more calories than the rest of us. For instance, one study found that they eat no more calories than day workers.

However, whether the total calories are different between shift workers and fixed day workers is up for debate, most studies find that the food choices made by shift workers are different. For instance, one study found that proportionately, shift workers eat more starches and sweets, and drink more alcohol, compared to those who don’t work shifts. Even though their calories may (or may not) be overall the same. So some healthy foods are getting replaced with less healthy foods.

But Why? The Hormonal Factors Behind Our Food Choices

So what is it that causes shift workers to make poorer food choices compared to fixed day workers? Is it simply a lack of willpower, or is there more to it?

Well, my friend, to blame willpower would be incorrect. Shift workers for the most part have tremendous willpower (they work night shifts, after all).

Just like blaming obesity completely on the lack of willpower would also be a very incomplete explanation. There are other factors at play.

There are four important hormones to consider when it comes to shift work.

Leptin is a hormone released by the fat cells, and it sends a signal to the brain, to let us know that we’re full. It controls appetite.

Ghrelin is leptin’s antagonist. It tells us that we’re hungry.

In an otherwise lean individual, who doesn’t work night shifts, leptin and ghrelin are finely balanced, we have a healthy appetite, and weight is maintained (within 5 pounds).

However, in someone working night shifts, leptin is decreased, and ghrelin is increased, according to this study. The net result: someone with this hormonal profile would feel hungrier, and it would be harder to satisfy their hunger compared to someone whose leptin and ghrelin are balanced.

Two other hormones to consider when it comes to shift work and health are cortisol and thyroid. Cortisol is a stress hormone, and the thyroid is the “gas pedal” on your metabolism. According to one study, cortisol is elevated, and thyroid is suppressed in folks working night shifts. The net effect: a slower metabolism and sluggishness.

The Impact of Eating During Shift Work

So whether shift workers eat more or not is still up for debate. However, it is fairly well established that some interesting things do happen when we eat at night.

Whenever we eat food, we use a certain percentage of the calories that we just ate on digesting the food that we just ate. So if we ate 500 calories, we don’t absorb 500 calories. Some of those have to be used to help the digestive system do what it’s supposed to do. How much exactly is determined by several factors, the largest of which is the composition of the meal (the ratio of carbohydrates, to proteins, to fats). This concept that we use some of the eaten calories to “power” other processes within the body is called “diet-induced thermogenesis.” “Thermogenesis” means that you produce heat. So yes, your body temperature rises slightly after meals, and it results in an increased metabolism by just a little bit.

Well, one study found that diet-induced thermogenesis is higher in the morning, compared to the night. That means that two people can eat the exact same meal with the same number of calories, but the person eating that meal earlier in the day will burn more calories than the person eating the same meal at night.

Another study looked at how the time when you eat affects your triglycerides. So in this study, researchers gave 2 groups of people the exact same meal. One group ate the meal at 1PM, and the other group ate the exact same meal at 1AM. The group that ate their meal at 1AM had a higher rise in their triglyceride levels, compared to the group eating their meal at 1PM.

In another study, the same meal was eaten at 4 different times, over a 10-day period. What they found was that compared to the meals eaten early in the day, the meals eaten at night (when 12 hours out of phase) resulted in a 17% increase in glucose (blood sugar), and a 22% increase in insulin. Hmm… so both sugar and insulin increased? Usually if sugar increases, and insulin is released, blood sugar comes down. The only time that both insulin and sugar are high is in… *drumroll, please*… insulin resistance, which is what happens in type 2 diabetics.

The researchers in this study even concluded that “circadian misalignment caused 3 of the 8 subjects to exhibit postprandial glucose responses in the range typical of a prediabetic state.”

Now isn’t that powerful? The blood sugar and insulin response differed not because of the differences in carbohydrate content, or anything about the meal (the carbohydrate content was identical between all 4 meals). The blood sugar and insulin response differed because of the time of day that it was eaten.

What To Do

So now, if you’re a shift worker, you must be thoroughly depressed, and think you’re screwed. I just spent over 1000 words describing how messed up is the physiology of shift workers. Well, fear not, because in this section, I’ll describe what you can do about it.

Best option: change your job.

This sounds like a joke, but it really isn’t. There’s a reason that a lot of health professionals will ask you whether changing your job is an option. That’s because they are trained to do that.

Humans are not owls. We are meant to function when it’s light out, and sleep when it’s dark out. There is no way to outsmart your physiology.

For all we know about shift work, we don’t yet know how to “get around” the negative consequences of it.

So yeah, if changing your job is an option, take that option.

If changing your job is not an option, there are a few other things you can do.

There are shift workers out there who are healthier than others. So in comparing healthier shift workers, to less healthy shift workers, one study found that important factors that contribute to good nutrition and physical activity were:

  • Beliefs about the benefits of exercise and good nutrition (if you believe it will help, and that it’s within your control, you’ll do it)
  • The use of what they call “self-monitoring” strategies (that’s things like counting calories, or counting steps, or counting protein, or counting anything that gives you some self-awareness)
  • Support from work colleagues (if your shift-working coworkers are doing it, you’re more likely to do it too)
  • Awareness of useful guidelines and strategies
  • Receiving compliments.

Basically, what this study is saying is that logistical management (ie planning) is absolutely huge for shift workers who want good health. You have to plan your exercise, and you have to plan your meals.

On the supplement side of things, there isn’t a lot of research into that area as it pertains to shift work, other than vitamin D. There seems to be a lot of vitamin D deficiency in shift workers (makes sense, since they’re sleeping during the time when it’s light out, and vitamin D is most abundant).

Other than that, since the research does not yet exist (to my knowledge) on the effects of different supplements on shift workers, we can only theorize.

In my opinion, helpful supplements for shift workers would be:

  • Vitamin D (no surprises there)
  • Adaptogens. These are specific herbs that help your adrenal glands manage the amount of cortisol they put out. Although adaptogens do have effects on organs outside of the adrenal glands, like your brain, digestive organs, etc. Examples of adaptogens include ashwagandha, holy basil, ginseng, rhodiola, and others.
  • Multivitamin

And of course, exercise is critical, since it actually somewhat helps with the regulation of your circadian rhythm.

Again, if all this sounds complicated to you, and you need help implementing these strategies, you can see if you qualify to work with us, by filling out this questionnaire.