Diet & Nutrition

The 16:8 Protocol

Roczen Eating Protocol

This involves periods of eating and fasting over a 24-hour period to help match your natural circadian rhythms. The type of time restricted eating most commonly used on the Roczen programme is known as ‘16:8’: this is where you fast for 16 hours and eat for 8 hours. Other Roczen protocols are ‘18:6’ or ‘22:2’, where the bigger number is the fasting period and the small number is the period in which you eat.

These longer fasts are generally not recommended for people new to fasting, and should only be undertaken with advice from your clinician.
The Roczen 16:8 protocol

The timings below are for illustrative purposes only. It is important to make your plan fit your life and schedule, and your clinician will help you to choose times that work best for you.

Here is the suggested example of how to plan your day:
  • Two meals a day.
  • First Meal between 12pm-2pm (finish by 2pm).
  • Second Meal between 6pm and 8pm (finish by 8pm). If you finish before 8pm you will be having a longer fasting period, which is beneficial.
  • You will then fast between 8pm until 12pm the next day (16 hour fasting).
  • In between meals, do not snack or consume any fluids with calories.
Other examples of Roczen protocols:
  • 16:8 – First meal 08:00-10:00, last meal 14:00-16:00 (having breakfast and later lunch)
  • 18:6 – First meal 12:00-14:00, second and last meal 16:00-18:00
  • 22:2 – One meal 18:00 and finishing by 20:00

Your Roczen Protocol has been individualised for you and is based on your metabolic profile, preferences, and medical history. If you wish to make changes to your protocol please reach out to your Roczen clinician.


What should I avoid or limit?
  • Avoid starchy carbohydrates (rice, bread, cereal, potatoes or grains)
  • Avoid added sugar and artificial sweeteners
  • Avoid alcohol during the Reset period
  • Avoid all fruit except Blueberries, Raspberries and Strawberries. These should be eaten after a meal
  • Avoid processed foods, try to focus on whole foods as much as possible

Other advice

Drink plenty of water throughout the day aiming for between 2-2.5 litre per day. This would be at least 8 cups/mugs each day.

During the fasting window (16 hours) you should not consume any food, snacks, or drinks containing calories e.g. fruit juice

Avoid diet or artificially sweetened drinks as these have various negative effects on health, reducing some of the benefits of fasting and often increasing cravings.

Black tea, black coffee and unsweetened herbal teas are fine to have outside of your eating windows. Milky drinks should ideally be consumed only in your eating windows. We also recommend that you avoid caffeine later in the afternoon as this may impact your sleep and disrupt your circadian rhythm.
There is no need to count calories, instead listen to your body and try to stop eating when you are pleasantly satisfied rather than overly full. This is known as ‘mindful eating’ - please see our resources on mindful eating and using the hunger scale for more information on learning how to develop this useful skill.

Aim to be physically active on a regular and moderate basis. We would recommend aiming for 150 minutes of moderate activity each week during this period. This would be equal to 30 minutes a day, 5 times a week with 2 days off. The activity can be simply walking or other exercises and split into 10-minute blocks if this would help. If you currently do more or wish to do more, please speak with the Roczen team.

We recommend that you weigh yourself in the morning after your morning routine to monitor your progress. If you feel that weighing yourself daily is too much and not helpful then aim to weigh yourself weekly on the same day, e.g. Sunday morning.

If you are feeling hungry, first of all drink a glass of water, as thirst is often mistaken for hunger. If you are feeling intolerably hungry 30mins after a glass of water, or if you feel weak/ dizzy/ unwell at any point, please break your fast and consult with your Roczen clinician before restarting the protocol.

If you feel seriously unwell at any point whilst on the Roczen protocol, please refrain from fasting, consult your GP/ 111 and inform your Roczen clinician.

August 31, 2023
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