How to Do Intermittent Fasting Based on a Shift Work Schedule

Shift work is more common nowadays not only in public services such as health care and law enforcement but also in customer services and hospitality. What your working schedule looks like is key when it comes to choosing an intermittent fasting regime. It is certainly more difficult to choose from the regular fasting plan for shift workers compared to 9-5ers. This article will talk you through some key issues with shift workers and how to choose a suitable fasting plan.

About Shift Works

Shift work typically refers to any schedule outside of the period of 7 AM to 6 PM. Shift workers sometimes work longer hours shifts that are >8.5 hours/>40hours/week as part of a compressed schedule. Some typical shift workers include:

  • Law enforcement
  • Healthcare workers, such as nurses and doctors
  • Nursing homes
  • Emergency services & hotlines
  • Security
  • Customer service and call centers
  • Factories and warehouse
  • Restaurants and hospitality
  • Grocery stores, convenience stores and bodegas
  • Bartending
  • Transportation like truckers or Uber drivers.

Shift Work & Circadian Rhythm

There are certainly some advantages of shift work, such as getting a day off on weekdays, avoiding peak hours during commutes, and higher pay. However, shift work, especially night shifts, have a working schedule that contradicts with the natural circadian rhythm, which disrupts the body’s homeostasis (the balance system your body try to maintain) and increases the risk for several health conditions, including

  • Cardiovascular disease
  • Insomnia
  • Gastrointestinal problems
  • Diabetes & difficulty managing chronic diseases
  • Obesity
  • Heart Attack
  • Psychological disorders
  • Some cancer
  • Sleep disorder, excessive sleepiness
    • Insomnia
    • Irritability
    • Depression
    • Lack of energy
    • headaches

Circadian rhythms are internally driven cycles of biochemical, physiological, and behavioral processes of living beings that rise and fall across the 24-hour day. It helps to regulate sleepiness and wakefulness, influences important functions in our body, such as hormone release and eating habits, and digestion.

You can rebuild a disrupted circadian rhythm by structuring the day around your shift schedule. Intermittent fasting alerts between fasting and eating windows, which is like cycling between sleep and awake time. Selecting an intermittent fasting plan based on your shift work schedule can help you to maintain a circadian rhythm and adjust to your shift work schedule much quicker.

Planning your Intermittent Fasting

For shift workers, the circle might work differently for 9-5ers. Therefore, matching an IF regime with a shift worker work schedule can help to rebuild your own circadian rhythm.

How to plan your fast is just the same as everybody else, and here is a basic step-by-step guide to help you choose a fasting plan.

Step 1. Choose a plan

This can be 14:10 or 16:8 to start with, then slowly build up the intensity if you need to. The longer the fasting window, the more intense the fasting plan is.

Step 2. Set your “START” & “END“ time (fasting & eating window)

Here are some things to consider as you set your windows:

  1. Pick a wake-up time so that you can get to work soon.
    1. Do you work a busy shift? It is better to fast during a busy shift.
    2. When do you feel most hungry? It is best to include that time in your eating window.
    3. Your access to food. Do you need to prepare your own food, or do you buy food? If you planned eating window in the midnight or early morning, you may have to prepare your own foods.
    4. If in doubt, ask your Coach within the Fastyle app.

Step 3. Plan your meals during the eating window

You must choose how many meals and when you have them. This can help you stick to the routine and eating window much easier while on a non-regular shift schedule. Aim for 2 main meals and 1-2 snacks. Generally, space your meals 2-3 hours apart, and finish eating at least 3-4 hours before your bedtime.

Here are some examples of three types of shift work schedules using a 16:8 fasting plan.

early morning shift
afternoon shift
night shift

If these three options aren’t right for you, you can follow the steps introduced above to customize your own plan. This will work for any fixed shift outside those three options.

Here is an example for a night shift:

  1. Choose an intermittent fasting plan like 16:8 regime.
  2. Eating window: 12 am – 8 am; Fasting window: 8 am – 12 am
    1. Start shift: 9 pm, and wake up time: 7-8 pm
    1. Yes, I will fast during my shift till “lunch”.
    1. I’m most hungry around 1-2 am and start eating window from 12 am – 8 am.
    1. Prepare food or buy food in advance for night shift, and cook meals after shifts.
  3. Meal plan
    1. Meal 1 – 12 am
    1. Snack 1 – 3 am
    1. Snack 2 – 6 am
    1. Meal 2 – 8 am

Shift Work and Sleep

Circadian rhythms have an important purpose: they prepare your body for expected changes in the environment and, for example, the time for activity, time for sleep, and time to eat. Sleep is an important part of our body. Shift work often influences sleeping patterns with a disrupted circadian, leading to the following syndromes:

  • compromised immune function
  • disrupted insulin/blood glucose system
  • promoting insulin resistance
  • unbalanced appetite hormones promoting overeating and obesity
  • impaired mental functioning, feeling anxious, irritated or depressed

A night-shift worker is likely most affected among these three types of shifts (early morning, afternoon, and night shift). Sleep is the result of a balance between sleep pressure and wakefulness. When your sleep pressure stays over wakefulness, you will fall asleep. And wake up when wakefulness over sleep pressure.

sleep and wakeness 1

This will be a problem with a night shift worker if the circadian system has not adjusted to working at night and sleeping during the day. The sleep pressure drives and circadian rhythms for wakefulness will not be synchronized and, as a result, will not work together. You may feel sleepy at work because your sleep pressure stays over wakefulness.

sleep and wakeness 2

So how do you adjust your sleeping time for synchronization?

In general, it is easier to change sleep times by getting up later or sleeping later than getting up earlier. This is because the circadian pacemaker tends to run longer than 24 hours, which makes it easier to sleep later.

To change sleep times to get up or go to bed earlier. The key is to initiate an external timing cue for the rhythm pacemaker within your body to promote sleepiness. The light/dark cycle of the sun is the strongest cue and strategy to minimize what can keep you up:

  1. Make the bedroom dark
  2. Create a good sleep environment
    1. Block out noise
    1. Keep bedroom’s temperature down
    1. Use a comfortable mattress and pillows
    1. Avoid watching TV, reading, or working in the bedroom
    1. Turn the clock face away
  3. Avoid blue light (electronic devices)
  4. Avoid daytime nap
  5. Avoid caffeine 5-6 hours before bedtime
  6. Avoid alcohol several hours before bedtime (Can you drink alcohol during intermittent fasting? Here comes an answer)
  7. Avoid heavy, spicy meals 2-3 hours before bedtime
  8. Avoid nicotine, several hours before bedtime
  9. Regular exercise during daytime
  10. Use sleeping aids, such as melatonin

Other tips for intermittent fasting on shift work.

What should you eat?

When it comes to what to eat during intermittent fasting, we recommend general healthy eating guided by the Dietary Guidelines for Americans and ratio your meals with MyPlate model by the USDA. You may also follow other healthy diets if needed such as Mediterranean Diet, Flexitarian Diet and different types of vegetarian diets.

What about day off?

Your body works the best when you get up at about the same time every day. If you are on a fixed shift schedule, you can pick awake time to get to work soon on your working days. Then get up at the same time on the weekend. If you have worked on different shifts, it is better to go to bed earlier on working days or take a nap to catch up on lost sleep during the weekend.

Adjust your fasting & eating window

Sometimes you may need to adjust your fasting and eating windows during the week to match your shift works. The easiest way to do this and avoid affecting your results is to extend or shorten your fasting and eating window by several hours and then resume your regular plan the next day. The key principle is to meet a minimal fasting time of 12-14 hours each day such as the image below:

Meanwhile, stick to your meal plan (how many meals you will have in a day) to avoid overeating when you’re adjusting your windows.


  • Shift workers with a disrupted circadian rhythm leads to many health conditions.
  • Intermittent fasting can help rebuild a circadian rhythm.
  • Plan an intermittent fasting plan for shift works following these steps
  • Sleep plays an important role in building and maintaining a circadian rhythm, follow the Tips to help adjusting sleep time and ensure good quality sleep.
  • Focus on healthy eating as always, or other healthy diets you may follow.
  • Adjust your plan around to meet your schedule and needs.

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