Fasting is one of the oldest wellness practices in human history.
It is also one of the most misunderstood.
- •Some people treat it like magic.
- •Some people treat it like punishment.
- •Some people use it wisely.
- •Some people use it recklessly.
The truth is that fasting can be a powerful tool.
But like any tool, it depends on how it is used, who is using it, and whether the person is ready for it.
That is Wellness That Fits.
What is fasting?
Fasting means voluntarily not eating for a period of time.
That is the simplest definition.
There are many types of fasting:
- •Intermittent fasting (time-restricted eating, such as 16:8 or 18:6).
- •Extended fasting (24 hours, 36 hours, 48 hours, 72 hours, or longer).
- •Water fasting.
- •Dry fasting (no food or water — this carries additional risks).
- •Modified fasting (very low calorie intake).
- •Religious or spiritual fasting.
Each type has different considerations, risks, and potential benefits.
The 18:6 approach
One of the most common and accessible forms of fasting is the 18:6 protocol.
This means eating within a 6-hour window and fasting for 18 hours.
For example, eating between 12:00 PM and 6:00 PM, then fasting until noon the next day.
This approach is popular because it is relatively simple, does not require extreme willpower, and can fit into many lifestyles.
Research on time-restricted eating has explored potential effects on weight, metabolic health, insulin sensitivity, inflammation, and circadian rhythm.
A review published through NIH describes intermittent fasting as an approach that may affect body weight, metabolic markers, and cardiovascular risk factors in some studies.
- •That does not mean 18:6 is right for everyone.
- •But it is one of the more accessible starting points for people interested in fasting.
What happens during fasting: a simplified timeline
When you stop eating, the body goes through stages:
0-4 hours: The body is digesting the last meal. Blood sugar and insulin are active.
4-8 hours: Blood sugar begins to normalize. Insulin levels start to drop. The body begins transitioning from using food energy to stored energy.
8-12 hours: Insulin continues to drop. The body begins using more stored glycogen (sugar stored in the liver and muscles). Some people begin to feel a shift in energy or hunger patterns.
12-18 hours: Glycogen stores are being depleted. The body begins shifting toward fat oxidation (using stored fat for energy). Some research suggests this is when metabolic benefits of fasting may begin to increase.
18-24 hours: The body is more fully in a fasted state. Fat oxidation continues. Some research suggests autophagy (cellular cleanup) may begin to increase during this window, though the exact timing varies by individual.
24-48 hours: Extended fasting territory. The body continues to use fat for fuel. Autophagy may continue. Hunger often decreases for some people during this phase. Electrolyte balance becomes more important.
48-72 hours: Deeper fasting state. Some research suggests immune system changes may occur during extended fasts. This level of fasting should not be attempted without understanding the risks and ideally discussing with a provider.
Beyond 72 hours: Extended fasting beyond 3 days carries additional risks and should only be done with medical supervision.
This timeline is simplified. Individual responses vary based on health, medications, activity level, hydration, and other factors.
Insulin and ghrelin: two hormones that matter
Two hormones are especially relevant to the fasting conversation:
Insulin is the hormone that helps the body process and store energy from food. When you eat, insulin rises. When you fast, insulin drops. Lower insulin levels may allow the body to access stored fat more easily.
Ghrelin is often called the hunger hormone. It signals the brain that the body wants food. Ghrelin tends to rise in waves, often around the times you normally eat. Many people find that hunger comes in waves during fasting and then passes.
Understanding these two hormones can help people approach fasting with more patience and less panic.
- •Hunger is not an emergency.
- •It is a signal.
- •And signals can be understood.
Fasting is not for everyone
This part matters.
Fasting is not appropriate for everyone.
People who should NOT fast without medical guidance include:
- •People with diabetes (especially those on insulin or blood sugar medications).
- •People with eating disorders or a history of disordered eating.
- •Pregnant or breastfeeding women.
- •Children and adolescents.
- •People with low blood pressure.
- •People taking medications that require food.
- •People with kidney disease, liver disease, or other serious health conditions.
- •People who are underweight.
Fasting can be dangerous for some people.
That is why it should be approached with understanding, not desperation.
If you are unsure whether fasting is appropriate for you, talk to a provider.
Fasting and faith
Fasting has deep roots in many faith traditions.
Christianity, Islam, Judaism, Hinduism, Buddhism, and other traditions have practiced fasting for thousands of years.
For many people, fasting is not just physical. It is spiritual.
- •It is a way to quiet the body so the spirit can speak louder.
- •It is a way to practice discipline.
- •It is a way to reset.
- •It is a way to remember that the body is not in charge.
I respect that deeply.
My own fasting practice is connected to my faith.
I fast not just for my body, but for my mind and spirit.
That is part of my Wellness That Fits.
My experience
Fasting has been one of the most powerful free tools in my own wellness journey.
When I was at my heaviest and most stressed, I started with simple time-restricted eating. I was not perfect. I did not follow a strict protocol every day.
But over time, fasting helped me understand my hunger, my habits, my cravings, and my relationship with food.
It helped me realize that I was eating out of stress, boredom, and habit — not always out of real hunger.
That awareness changed everything.
- •Fasting did not fix my life.
- •But it helped me see my life more clearly.
And clarity is where change begins.
How this fits TwentyAgain
TwentyAgain is not a fasting program.
- •We do not prescribe fasting.
- •We do not sell fasting plans.
- •We do not claim fasting cures anything.
But we believe in education.
And fasting is one of the most powerful, free, ancient tools available to people who are ready to explore it responsibly.
If you are exploring weight support, hormone health, or general wellness through TwentyAgain, fasting may be part of your bigger picture.
- •But it should be approached with understanding.
- •Not desperation.
- •Not punishment.
- •Not as a replacement for medical care.
That is Wellness That Fits.