Who should NOT fast?
You should not fast if you are:
- Underweight (BMI < 18.5)
- Pregnant – you need extra nutrients for your child.
- Breastfeeding – you need extra nutrients for your child.
- A child under 18 – you need extra nutrients to grow.
You can fast, but may need supervision, under these conditions:
- If you have diabetes mellitus – type 1 or type 2.
- If you take prescription medication.
- If you have gout or high uric acid.
Won’t fasting put me into starvation mode?
No. This is the most common myth about fasting. In fact, the truth is just the opposite. Studies conclusively show that fasting increases basal metabolic rate. Learn more
Can I exercise during fasting?
Yes. You should continue all your usual activities, including exercise while fasting. You do not need food to provide energy for exercise. During this time, your system will burn body fat for energy. Excellent! Learn more
What are the possible side effects?
There can be a number of possible nuisance side effects. Here’s what to do if you encounter them:
- Constipation is common. Less going in means less going out. You don’t need medications unless you experience discomfort. Standard laxatives can be used to help.
- Headaches are common and tend to disappear after the first few times on fasts. Taking some extra salt often helps mitigate such headaches.
- Mineral water may help if your stomach tends to gurgle.
- Other possible side effects include dizziness, heartburn, and muscle cramps. Learn more
A more serious side effect is the refeeding syndrome. Fortunately, this is rare and generally only happens with extended fasts (5-10 days or more) when one is undernourished. Learn more
How do I manage hunger?
The most important thing to realize is that hunger passes like a wave. Most people worry that hunger will continue to build until it is intolerable, but this does not happen. Instead, hunger comes in a wave. If you simply ignore it and drink a cup of tea or coffee, it will often pass.
During extended fasts, hunger will often increase into the second day. After that, it gradually recedes; and many people report a complete loss of hunger sensation by day 3-4. Your body is now being powered by fat. In essence, your body is ‘eating’ its own fat for breakfast, lunch, and dinner and therefore is no longer hungry. Learn more
Won’t fasting burn muscle?
No. During fasting, the body first breaks down glycogen into glucose for energy. After that, the body increases fat breakdown to provide energy. Excess amino acids (the building blocks of proteins) are also used for energy, but the body does not burn its own muscle for fuel.
It would be a long stretch of the imagination to think that our bodies store energy so carefully in the form of glycogen and fat only to burn muscle when it is needed.
Fasting has been practiced for thousands of years without difficulty. In my experience with over 1,000 patients on various fasting regimens, exactly zero have complained that they have noticed significant muscle loss. Learn more
What are your top tips for intermittent fasting?
Here are the nine top tips, briefly:
- Drink water
- Stay busy
- Drink coffee or tea
- Ride out the hunger waves
- Don’t tell anybody who is not supporting that you are fasting
- Give yourself one month
- Follow a low-carb diet between fasting periods. This reduces hunger and makes fasting much easier. It may also increase the effect on weight loss and type 2 diabetes reversal, etc.
- Don’t binge after fasting
How do I break a fast?
Gently. The longer the fast, the more gentle you must be. For short duration fasts, eating too large a meal after fasting (a mistake that we have ALL done, myself included) will usually give you a stomach ache. While this is not serious, people learn quickly to eat as normally as possible after a fast.
Isn’t it important to have breakfast every morning?
No, it’s not. This is an old misconception based on speculation and statistics, and it does not hold up when it’s tested. Skipping your morning meal just gives your body more time to burn fat for energy. Since hunger is lowest in the morning, it is often easiest to skip it and break your fast later in the day. Learn more:
Can women fast?
Absolutely. The only exception is women who are underweight, pregnant or breastfeeding. Other than that, there is no reason not to fast. Women have problems during fasting, but so do men. Sometimes women do not get the results they want, but that happens to men, too.
Women have fasted for thousands of years without incident. Studies show that the average weight loss for women and men who fast is similar. Learn more about women and fasting
Isn’t fasting the same as reducing calories?
No. Not at all. Fasting reduces the time you spend eating and addresses the question of ‘when to eat’. Calorie reduction addresses the question of ‘what to eat’. They are separate issues and should not be confused with each other.
Fasting does reduce calories but it benefits extend far beyond that. Learn more
Will I lose weight?
Absolutely. It is almost inconceivable that you will not lose weight if you do not eat.
I call fasting ‘The Ancient Secret of Weight Loss’ because it is one of the most powerful dietary interventions for weight loss, yet it has been almost completely ignored it in recent years. Learn more