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Intermittent Fasting - Boulder Holistic Functional Medicine (stacked rocks)

Unlock the Power of Intermittent Fasting: Pros, Cons, and Secrets Revealed

Fasting is an ancient therapeutic technique that dates back to the 5th century BCE. Back then, fasting mainly was a religious practice, but it was also used to treat certain illnesses.

It took the advances of modern science to reveal the many benefits of fasting for your health. Intermittent fasting is the most recent trend in fasting, a practice that requires you to abstain from eating or drinking during a certain portion of the day. Other types of fasting include extended fasting, religious or spiritual fasting, time-restricted feeding, and modified fasting.

Boulder Holistic Functional Medicine in Boulder, Colorado, recommends fasting for a variety of health reasons. Keep reading for more fasting benefits and first-time fasting tips from a functional medicine practitioner.

Benefits of Fasting

The benefits of fasting are incredible and include better brain function, digestion, insulin sensitivity, body composition, and antioxidant activity. Fasting can reduce inflammation, blood pressure, and blood sugar levels. A single day of fasting is enough to see multiple benefits. 

Fasting for a more extended period of time is not necessarily better for you. In fact, longer fasts may not work for people with pre-existing medication conditions (including people with diabetes, metabolic syndrome, or symptoms related to unbalanced blood sugar), the elderly, children, and pregnant women.

Fasts that last 24 or 48 hours are done less frequently – about once or twice a month at most. On the other hand, time-restricted eating can be done daily in 8-, 12-, or 16-hour intervals. Time-restricted eating is also called prolonged nightly fasting and is one of the more common fasting practices used today.

Intermittent Fasting - Boulder Holistic Functional (fasting clock)

Note: During 24-hour and 48-hour fasts, you avoid caloric beverages and food but you should always drink plenty of water!

Here is a breakdown of the benefits of a 24- and 48-hour fast.

Benefits of 24-Hour Fast

When you go 24 hours without food, your glucose storage is depleted and your body starts to turn the glycogen in your liver and muscles into glucose for extra energy. Your LDL (“bad”) cholesterol and triglyceride levels go down and your HDL (“good”) cholesterol levels increase.

Most types of fasting have some sort of fat loss or weight loss benefits. Some studies show improved appetite regulation and more diversity in the gut microbiome, both of which contribute to potential weight loss and better gut health overall.

Benefits of 48-Hour Fast

After 24 hours, the glycogen stores in your liver and muscles are used up. Your body starts to burn fat for energy and produce ketones. During a 48-hour fast, your body moves into ketosis, a metabolic process that promotes long-term weight loss and appetite control.

The benefits of a 48-hour fast include anti-aging benefits, rapid weight loss, increased insulin sensitivity, improved learning and memory, detoxification, and more.

Some people’s bodies will store fat in response to the lack of food and you don’t need to fast for 48 hours to access ketosis. The Keto Diet is designed to help people reach ketosis with a diet low in carbs and high in fat. Intermittent fasting – a type of time-restricted eating that limits the window during which you consider calories during the day – can also instigate ketosis in the body.

Always listen to your body during long periods of fasting. Fasting may make you feel weak, tired, or irritable. You may want to consult with your functional medicine provider before you start a fasting protocol, especially if you have an existing medication condition.

Pros and Cons of Intermittent Fasting

Intermittent fasting is one of the more well-known forms of fasting. Types of intermittent fasting include time-restricted eating, alternate-day fasting (or fasting intervals), and intermittent energy restriction.

The pros of intermittent fasting include:
  • Burn fat
  • Better heart health
  • Improved memory and learning capability
  • Anti-aging
  • Detoxification
  • Lower cholesterol
  • Less restrictive than 24- or 48-hour fasts
  • Easy to incorporate into a daily routine
The cons of intermittent fasting include:

Many of the cons of intermittent fasting will go away as your body adjusts to the new caloric restrictions. However, if you have a medical condition or your side effects worsen over time, you should consult with your functional medicine doctor.

Fasting Mimicking Diet

Eating healthy during intermittent fasting


For those of you who are not comfortable with the idea of fasting, the fasting-mimicking diet can provide many of the same fasting benefits using a low-calorie diet plan. 

You don’t have to go hours or days without food, instead, you eat small, plant-based meals for five days. 

The lack of protein and carbohydrates tricks your body into fasting mode without the strain of missing meals.

Tips on Fasting

First-time fasters are often worried that the lack of food will disrupt their life, and to a certain extent, they aren’t wrong. When you are fasting, you need to treat your body gently. You will not have the same energy and you may feel irritable or foggy. 

A few tips for first-time fasting:

  1. Drink plenty of water
  2. Stop if you feel sick, faint, or can’t sleep
  3. Cut down your activity
  4. Don’t break your fast with a huge meal
  5. Try meditating to control food anxiety
  6. Stock up on flavored waters and other no-calorie beverages like lemon water

Fasting doesn’t work for everyone. People with eating disorders or unhealthy food relationships should not try fasting. Certain medications conditions and chronic illnesses may also affect your body’s ability to fast. 

Beach during sunset - intermittent fasting Boulder Holistic

If you’re hesitant to try fasting or simply want to learn more, contact Boulder Holistic to discuss which type of fasting will work best for your body.

Work with Boulder Holistic Functional Medicine

Boulder Holistic Functional Medicine in Boulder, Colorado, is happy to help you on your fasting journey. Functional medicine uses a full-body approach to wellness. The food you eat (or the lack of food in this case) is a great influence on your overall health. 

Not all types of fasting work for everyone, so contact our office to schedule an appointment for a personalized recommendation!

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Dr. Terri Rebibo Fox

Dr. Terri Fox is a holistic, integrative, functional medicine doctor in Boulder, Colorado. She works on your behalf as a medical detective searching for the underlying dysfunction, instead of just treating your symptoms. She has expertise in fatigue, bio-identical hormones, sleep disorders, gastro-intestinal dysfunction, and Chronic Inflammatory Response Syndrome from mold toxicity and Lyme disease.