Intermittent Fasting for Weight Loss

Two-thirds of people in the Western world are overweight, and one-third of those are obese by definition.

Fasting is a time tested tool that has been used for generations, dating back to our ancestors. At it’s very core, fasting helps to burn body fat. Fat is just ‘stored energy’, and fasting helps to utilize that energy source.

When eating, you are in a ‘feasting state’. More food is ingested than can be immediately used. Your body uses the extra energy from your food one of two ways–either stores it as glycogen in your liver or, when the glycogen stores are full, it is converted into fat. Glycogen stores are easy to access but have limited space; whereas fat storage is unlimited but is hard to access. 

In a ‘fasting state’, you start by burning through all the glycogen stores in your liver. When glycogen has been depleted, fat is utilized for energy. You switch from being a sugar burner to being a fat burner. You literally start to eat your own fat for energy. This happens at about hour 12 of a fast–around 7am if you stopped eating the previous night at 7pm.

Insulin is the key hormone in energy storage–it tells your body whether to use or store energy from food. 

  • High insulin levels occur in a ‘feasting state’, and tell your body to store energy from food.
  • Low insulin levels occur in a ‘fasting state’, and tell your body to release energy from body fat.

The body really only exists in two states; the fed/insulin high state, and the fasted/insulin low state. Either we are storing food energy, or we are burning it. If eating and fasting are balanced, then there is no net weight gain. If we start eating the minute we wake up, and do not stop until we go to sleep, we spend almost all our time in fed state. Over time, weight gain occurs. We have not allowed for any time to burn food energy. To restore balance or lose weight, we need to increase the amount of time we spend in fasting state burning energy. 

The Benefits of Fasting Go Beyond Weight Loss

  • Weight loss/body fat loss
  • Improved mental clarity and focus; fat is a better fuel source for your brain!
  • Lowered blood sugar and insulin levels
  • Increased energy
  • Lowered cholesterol
  • Prevention of cognitive impairment like Alzheimers
  • Longer life as it promotes healthy genes and longevity
  • Autophagy–the process of getting rid of old cellular parts so energy can be spent on new ones
  • Starves ‘bad’ bacteria in the gut

How to do it:

There are many options for fasting-pick something that you think will fit well into your lifestyle. Whether short or long fasts speak to you, they all have proven benefit. 

Allowable on a fast: clear liquids like coffee, tea, water. 

Options for shorter fasts (less than 24 hours):


This involves fasting daily for 16 hours, with an 8 hour eating window. You eat all your meals in an 8 hour period and fast the rest of the time. People typically eat 2 to 3 meals during this time frame.

Normally people fast between 7pm-11am, and skip breakfast, but you can do it any way you like. It may be easier for you to skip dinner for example, so you could fast from 2pm to 6 am instead.


This involves fasting for 20 hours with a 4 hour eating window. Generally you would eat 1-2 meals during this time period. An example of timing would be fasting 7 pm to 3pm the next day.

Options for longer fasts (more than 24 hours):

24 hour fasts

This involves fasting from dinner to dinner, or lunch to lunch. If you eat dinner the first day, you would skip breakfast and lunch the next, and then eat dinner. On this plan you are still eating one meal per day. This option is generally done 2 to 3 times per week.

5:2 Fast

This involves 5 regular eating days and 2 full fasting days per week. It is allowable to eat 500 calories on the fasting days.

36 hour fasts

This involves fasting for the entire day. For example, if you eat dinner on day 1, you would not eat again until breakfast on day 3, which typically equals 36 full hours.

Fat and Bone Broth Fasts

If clear liquids aren’t cutting it for you, you can add fat to your liquids–full fat coconut milk, cream, MCT oil, butter. Fat provides very little insulin response, and can make fasting easier. Think bulletproof coffee. 

Another good alternative is to add in bone broth. Both fat and bone broth fasts are not ‘true’ fasts as they contain calories, but they have such a low insulin response that if it helps you meet your goals, it may be worth it.

There are other ways to reduce insulin and burn fat.

Focus on fat burning activities like:

  • Low carbohydrate diet
  • Low calorie diet
  • Intermittent fasting
  • High intensity exercise
  • High nutrient density

Avoid fat storage activities:

  • High carbohydrate diet
  • High calorie diet
  • Frequent meals/snacking
  • Empty calories

Absolute Contraindications:

  • Pregnancy and Breastfeeding as these conditions require a higher nutrient need
  • Children as it restricts nutrients they need to grow and develop
  • Underweight adults (<18.5 BMI)

Be Cautious in These Situations:

  • Diabetes
  • Prescription medications that require food intake
  • Elevated uric acid levels and/or gout

SOURCES: prevent cognitive impairment promotes gene expression and longevity improves cancer tx improves DM2