A Beginner's Guide to Fasting: Everything You Need to Know

Fasting is the intentional practice of going without food, or sometimes food and drinks, for a set period of time. People have done it for thousands of years for religious, cultural, and health-related reasons.

You already fast every day without thinking about it. The word breakfast literally means breaking the fast after a night of sleep.

In recent years, fasting has gained attention for another reason. Research suggests it can influence metabolism, support cellular repair, and affect the way the body produces and uses energy. Scientists are also studying its potential role in healthy aging and disease prevention.

At Thrive Wellness Center, we look at health through the bigger picture. Just like chiropractic care focuses on helping your nervous system and body function at their best instead of simply masking symptoms, fasting is often used as a way to support the body's natural repair processes rather than chasing quick fixes. The two aren't the same treatment, but they share a similar philosophy (creating the right conditions for your body to work the way it was designed to).

Key Takeaways

• Fasting gives your body a break from constant digestion, allowing it to shift into processes like fat burning, cellular repair, and improved metabolic function.
• At Thrive Wellness Center, fasting is viewed as one piece of the bigger picture and can complement chiropractic care by supporting the body's natural ability to heal and recover.
• You don't need to jump into long fasts. Starting with a 13 to 15-hour overnight fast is a simple, sustainable way for most people to begin.
• How you end a fast matters. Breaking it with nutrient-dense, low-insulin foods and staying hydrated can make the experience safer and more effective.
• If you're doing all the right things and still don't feel your best, it may be time to look beyond your diet and explore whether underlying issues with your spine, nervous system, or overall health are holding you back.

What Happens to Your Body During Fasting?

When you stop eating, your body doesn't suddenly shut down. It simply changes where it gets its energy from.

At first, it uses the glucose stored in your blood and liver. Once those reserves start running low, your body begins breaking down stored fat into fatty acids to keep you going. As that happens, it also starts producing ketones and enters a metabolic state called ketosis, where fat becomes the primary fuel source instead of carbohydrates.

You can think of it like switching from using the cash in your wallet to dipping into your savings account. The energy is still there, but your body has to access it differently.

As your fast continues, several changes may begin to take place:

• Around 13 hours: Growth hormone production starts to increase.
• Around 16 to 18 hours: Autophagy, the body's natural cellular cleanup process, begins to ramp up.
• Around 24 hours: Intestinal stem cells may begin repair processes, and many people start relying more heavily on stored fat for energy.

Benefits of Fasting

One of the recommendations we make to patients is to consider fasting. Not because it's trendy, but because the body was designed to spend periods without constantly digesting food. Giving your digestive system a break allows your body to shift its focus to other important processes like cellular repair, regulating blood sugar, and using stored energy more efficiently.

While fasting isn't a replacement for chiropractic care when it's done safely and appropriately, it can complement the work we're already doing by supporting the body's natural ability to heal and recover.

Some of the potential benefits of fasting include:

• Increased growth hormone production
• Activation of autophagy
• Stem cell generation
• Blood sugar stabilization
• Reduced inflammation

It may also contribute to improvements in:

• Immune function
• Mental clarity and brain health
• Detoxification processes
• Weight management
• Longevity and healthy aging

Types of Fasting

The best method depends on your goals, experience, and overall health. At Thrive, we typically encourage patients to start simple rather than jumping straight into extended fasts. Building consistency is far more important than pushing yourself too hard.

1. Intermittent Fasting (IF)

This is the most common starting point and one we often recommend. You cycle between eating and fasting windows, with many people naturally fasting for 13 to 15 hours overnight.

2. Autophagy Fasting

A slightly longer fast of around 16 to 18 hours, which is thought to encourage the body's cellular cleanup process known as autophagy. Many people choose to break this fast with healthy fats before introducing a full meal.

3. Dinner-to-Dinner Fasting

Finish dinner, then wait until dinner the following day before eating again. Some people include this once or twice a week as a way to extend their fasting window without making it part of their daily routine.

4. Dry Fasting

This involves avoiding both food and liquids for 12 to 24 hours. Because it limits hydration, it should be approached with caution and isn't appropriate for everyone.

5. 36 to 48 Hour Water Fasting

Only water is consumed during this period. Some people use longer fasts to encourage deeper metabolic changes and fat utilisation, but they should only be attempted when you're well-prepared and understand the potential risks.

6. 3 to 5 Day Water Fasting

These extended fasts are generally reserved for experienced individuals. They require careful planning and aren't something we'd recommend jumping into without proper guidance.

7. Fast-Mimicking Diet

Rather than eliminating food completely, this approach uses a very low-calorie, low-protein eating plan that's designed to produce some of the same biological effects as fasting while still allowing limited food intake.

How Long Should You Fast?

One of the questions we get asked most when it comes to fasting is, "How long should I do it?" The answer depends on your goals and your experience. You don't have to jump into a 72-hour fast to see benefits. 

13 to 15 Hours

For many, this is the sweet spot and the easiest place to start. It fits naturally around your sleep schedule and may support:

• Increased growth hormone production
• The early stages of ketosis, where your body starts relying more on stored fat for energy

17 to 24 Hours

As the fasting window gets longer, your body may begin shifting into deeper repair and maintenance processes, including:

• Cellular repair
• Autophagy and the recycling of damaged cells
• Improved mental clarity for some people
• Changes in metabolism that researchers continue to study for their potential long-term health benefits

36 to 48 Hours

Longer fasts can produce more significant metabolic changes, including:

• Deeper fat metabolism
• Increases in dopamine, which may affect motivation and focus
• Biological processes linked to healthy aging

72 Hours

Extended fasts are typically reserved for experienced individuals and should be approached carefully. Research suggests they may be associated with:

• Immune system regeneration
• Increased stem cell activity

At Thrive Wellness Center, we don't believe longer is always better. A consistent fasting routine that fits your lifestyle is far more sustainable than pushing yourself through extended fasts you'll never want to repeat.

How to Start Fasting

If you've never fasted before, don't overcomplicate it. You don't need a five-day water fast or an expensive program to get started. 

1. Start With an Overnight Fast

We recommend beginning with a 13 to 15-hour fasting window. For most people, that simply means finishing dinner a little earlier and waiting until breakfast the next morning. You're already sleeping for much of that time, which makes it easier to stick with.

2. Extend Your Window Gradually

Once your body adapts, you can slowly increase your fasting period if it aligns with your goals. Many people find the transition easier when they reduce processed carbohydrates and include healthy fats in their diet, helping them stay satisfied between meals.

3. Experiment With Longer Fasts

If your goal is to encourage processes like autophagy, you may choose to work toward fasting for 17 hours or longer. Just remember that more isn't always better. Pay attention to how you feel, stay hydrated, and choose a routine that you can maintain rather than one that leaves you exhausted.

Like chiropractic care, fasting isn't about forcing your body into change. It's about giving it the right conditions to function the way it was designed to.

Breaking Your Fast

Did you know that ending your fast the right way is just as important as how you start it?

Research has found that after prolonged fasting, your body's response to food changes, and eating a large, high-carbohydrate meal straight away can lead to a much bigger glucose and insulin response than expected. 

Dr. Ben Ozanne always says to think of it like warming up before exercise. You wouldn't sprint the second you step onto a track, and you shouldn't shock your digestive system after it's had hours or days to rest.

Start with foods that have minimal impact on insulin levels, such as:

• Bone broth
• Olives
• Avocado
• Nut butter

Try to avoid reaching for bread, pastries, sugary drinks, or other high-carbohydrate foods as your first meal. 

When to Stop Fasting

If fasting is making you feel worse instead of better, it's time to stop. The goal is to support your health, not push through warning signs or ignore what your body is telling you.

You should stop fasting if:

• Ketone levels exceed 7 mmol/L
• Blood sugar drops below 40 mg/dL
• You feel unwell or experience concerning symptoms

Feast Days

Fasting only works well when it's balanced with eating well. Your body still needs enough protein, healthy fats, vitamins, minerals, and calories to repair tissues, maintain muscle, and support your nervous system.

Feats give your body the nutrients it needs to replenish what you've used, support a healthy metabolism, and make fasting something you can maintain long term instead of a short-lived challenge.

But don’t forget about your hydration. Whether you're fasting or eating normally, drinking enough water and replacing electrolytes like sodium, potassium, and magnesium can help support energy levels, muscle function, and overall well-being.

Still Not Feeling Your Best? 

Fasting can be incredibly beneficial, but it won't solve every health concern. If you're still struggling with low energy, recurring headaches, digestive issues, inflammation, neck or back pain, or you just know something feels off, it's worth taking a closer look.

At Thrive Wellness Center, we believe your body usually gives you clues before it gives you answers. The challenge is figuring out what's behind those symptoms. That could mean looking at your spine and nervous system, but it also means understanding your daily habits, movement, nutrition, sleep, and overall health.

You don't have to keep guessing. If you've been doing all the "right" things and still aren't where you want to be, we'd be happy to help you understand what's going on and whether chiropractic care could be part of the solution.