How to Fast for Longer

Are you looking to take control of your health once and for all? That’s great! In your exploration of the secret to health and longevity, you may have read about the benefits of intermittent fasting. For example, you may have discovered that taking control of your eating window can lead to increased weight loss, decreased blood pressure, improved exercise performance, improved brain health and reduced inflammation.

The only problem is that skipping out on eating for significant periods of time, especially during waking hours, is hard. And especially at first, you may struggle to reach your goals.

That’s why it’s essential to set reasonable goals for what you want to achieve. Then, you can take steps to take control of your eating window and health goals.

How Long Should You Fast?

There are no absolute rules surrounding the length of fasts. If you are to experiment with complete fasting, in which you consume no food, you may want to limit this to 1-3 days—perhaps with experimentation with more prolonged fasts. This can be a rewarding experience, but it is tough. It’s a good idea to only follow a complete fast with the approval of a qualified healthcare provider. 

That said, when most people consider fasting, they think of time-restricted feeding or intermittent fastin, which is simply restricting food for a certain period of time each day. 

The goal is to find a fasting style that fits your lifestyle and needs well enough that you can keep up with it. While any fast may prove helpful, extending the time of the fast (e.g., 18 hours vs. 12 hours each day) may yield greater benefits, although this remains to be determined. Regardless, most people who practice fasting claim enhanced benefits with longer fasts. Therefore, methods of extending the fasting window have been proposed. 

Choosing the right fasting schedule

Before you seriously limit your fasting window or worry about how to fast for longer, choose the right fasting style for you. We have put together a complete guide to intermittent fasting, but these are the 4 main types of fasting.

  • Time Restricted Feeding (TRF): Food intake is typically limited to a 6-12 hour window.
  • Alternate Day Fasting (ADF): You fast every other day or during certain days a week. On the other days, you follow ad libitum caloric intake (not limiting calories, just eating until you feel full).
  • Modified Alternate Day Fasting (MADF): Similar to ADF, this plan follows an alternating day pattern, where you limit your calories on fasting days to about 15%-25% of your caloric needs, then follow the ad libitum caloric diet on non-fasting days.
  • Prolonged Fasting (PF): The most classic form of fasting, prolonged fasting involves a complete fast for 4-7 days or longer. Again, only follow this approach under the guidance and approval of a qualified healthcare provider.

When you start struggling, experiment with these different fasts to see if one is more manageable. For example, if adhering to ADF feels impossible, maybe try MADF or start with an 8-hour time-restricted fast.

How long can you safely fast?

The human body can fast for a surprisingly long period (as long as it’s kept adequately hydrated). 

A study of 1,422 participants fasting for periods between 4-21 days with a caloric intake of 200-250 kcal showed positive results in weight loss, blood pressure, glucose regulation, ketone levels, and overall emotional well-being. In addition, fewer than 1% of participants reported adverse effects, and 84.4% of those with pre-existing health complaints reported improvements. 

Other studies have also shown that long-term fasting (from 4-21 days) can have very beneficial effects. However, you should exercise caution with repeated prolonged fasts.

The short and long-term effects of fasting for longer than 21 days haven’t been studied thoroughly. While the human body can survive for far longer, fasting beyond 3 weeks is generally considered a dangerous practice.

Prolonged fasts can be especially dangerous for those who are pregnant, breastfeeding, under the age of 18 or over the age of 75. Before starting any fast, talk to your doctor to ensure it’s a wise decision that your body can tolerate. 

5 Ways to Fast for Longer

Following some general guidelines can improve your experience and results with fasting and increase your fasting windows.

1. Prep accordingly

Preparing your mind and body is incredibly important to the overall success of your fast. 

Once you decide to start fasting, it’s tempting to jump right in while you’re still excited. But you’ll thank yourself for taking a bit before to plan your fast, figure out your goals and find some distractions and coping mechanisms for when you’re tempted to quit.

2. Start gradually

Pick a goal to aim for your fasting window. For example, you may want to restrict your eating to 8 hours a day. Or perhaps you want to do a prolonged fast for seven days.

But that shouldn’t be your first attempt. Your body will go through a lot of metabolic changes when you first begin to fast. As a result, you may experience hunger pangs more severely at first as your body adjusts to caloric restrictions.

But once it gets easier, push yourself to increase your fast lengths. Jumping in the deep end is a great way to burn yourself out and get discouraged. It’s far better to accept the baby steps and work to fast longer over a period of time.

3. Eat right

While fasting centers around not eating food, the whole process becomes much easier when you consume the right food before and after fasting periods.

Before you fast for the first time, spend a few days giving your body a quality diet. Following the Mediterranean diet is highly recommended.

Most forms of intermittent fasting include periods where you don’t have to limit your caloric intake. But this doesn’t mean you should gorge yourself during those periods. Instead, you should try to be even more intentional with your eating (while still enjoying yourself).

Ease yourself back in after fasting with a small, easy-to-digest meal (e.g., a smoothie or light soup) before attempting heartier, nutrient-dense foods. Avoid processed and high-calorie foods during non-fasting days to help your metabolism out.

4. Drink right

Staying hydrated eases some of the more uncomfortable side effects of fasting and satisfies some of the mental need to consume something.

But be conscious of the liquids you consume during fasting, since calorie-containing drinks will break your fast.

However, beyond just the benefits of hydration, certain liquids can also help with general appetite suppression. For example, coffee is commonly thought to be an appetite suppressant. Anecdotally, it seems to work quite well for many people, despite clinical trial data being conflicting

Additionally, ketone ester drinks have shown very positive results in lowering overall hunger, suppressing appetite, and increasing the feeling of fullness after eating. Tecton can help you push through the last legs of your fast by keeping your mind off food and the hunger pangs at bay through natural appetite suppression.

5. Get enough rest

Obtaining adequate nightly sleep is of vital importance when energy intake is lower, as is reducing overall physical activity—if adhering to a complete fast. Many people fasting for weight loss benefits may also push themselves to exercise during fasting. If adhering to a complete fast, this isn’t the best idea, as you will have little energy and risk feeling ill if you push yourself too hard. Instead, stick to lower-intensity exercises like walks or yoga, and schedule higher-intensity workouts for your off days.

If following an intermittent fast or ADF, simply time your exercise session to a period when you know you will be able to consume food after the session, as you need to consume protein post-exercise to support recovery. 

Even trained athletes should stick to low-intensity exercise while fasting at first to ensure they recover before any athletic events.

You Can Achieve Your Goals to Fast for Longer!

Taking up the practice of fasting can change your life. Your mind, body, and spirit will all thank you. But severely limiting your eating window can be highly challenging. Choosing the correct fasting schedule, easing in, eating and drinking correctly, and not over-exerting yourself can all help you increase your fasting window.

And for the times you feel like you can’t push through, Tecton can help. It will help to reduce your appetite, in particular during times when you are attempting to go without food—it’s the little extra boost you might need to extend the fast another 1-2 hours before eating again. Tecton can also increase the level of ketones in your body—providing an energy source that should not interfere with your fast. Consider using Tecton as a bridge to extend your fast, whether you are fasting for 8 hours or doing a multi-day fast.


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