Intermittent Fasting (IF) has become increasingly popular and understandably so! Many people who try IF report many benefits including increased energy, losing weight, and getting better blood labwork markers. However, this isn’t the case for everyone – there is no magic diet that suits us all. 

There are many forms of IF, but the most popular version we see is to restrict your eating window during the day to increase the hours you are fasting. For example, someone might have their first meal at 12 pm and stop eating at 6 pm. Their eating window would be 6 hours and their fasting window would be 18 hours from dinner to breakfast the next day. 

Why?

The different versions of IF can have some great health benefits. Many cultures even incorporate fasting as part of their religious or cultural traditions. We also now have research to show that IF can help:

• Decrease inflammation
• Promote autophagy (the system by which our cells clean, repair or destroy themselves)
• Lower blood pressure
• Improve blood sugar and insulin sensitivity
• Increase longevity 

Not to mention, many individuals find that IF helps with weight loss. This data makes it seem that everyone should try IF! When we do look at the studies, however, we will see that most of the studies were conducted with healthy male participants. We currently don’t have a great understanding of how women respond to IF based on their hormonal changes throughout a menstrual cycle. 

Who Fasting may NOT be for people with: 

• Irregular menstrual cycles
• A history of eating disorders
• Intense mental/emotional stress
• Pregnant or breastfeeding women 
• Chronic illnesses 
• Adrenal imbalances
• Thyroid imbalances
• Poor sleep

*People with Type 1 or Type 2 Diabetes should consult their doctor before attempting Intermittent Fasting 

Signs that Intermittent Fasting may not be working for you: 

• Feeling STARVING while fasting and/or after breaking the fast 
• No hunger cues
• Running on adrenaline all day (usually followed by a crash)
• Feeling like eating is out of control 
• Increased cravings
• Skipped or irregular menstrual cycle
• Increased anxiety 
• Increased blood sugar highs and lows
• Gaining weight 
• Constipation
• Headaches/migraines occurring in the afternoon

Tips for Successfully Implementing Intermittent Fasting 

1. Recognize the signs that IF is not working  
   1. Work on listening to your body (this takes practice!). Adjust your fasting window according to hunger and activity levels. If you had an intense workout on Sunday, you may wake up feeling hungrier on Monday. Don’t push your fasting to reach an arbitrary number of hours. Eat when you are hungry! 
   2. Familiarize yourself with the other signs that IF may not be working for you listed above
2. Don’t decrease your total amount of food
   1. IF is designed to change your eating window, NOT change the number of calories you eat per day. Simply removing a meal from your day could put your body in a state of “starvation & conservation”. When we aren’t eating enough for our lifestyle, the body often prioritizes conserving our food as energy in our fat tissue. This is a primal, life-saving adaptation that was very useful in times of starvation or famine. Today, restricting calories may contribute to weight gain or the inability to lose weight. 
3. Practice a 10 hour (or less) fast
   1. Follow these simple rules for a more moderate IF schedule:
      1. Stop eating dinner 1 hour before bed
      2. Sleep 8 hours
      3. Eat after being awake for 1 hour (use this time to drink water and get ready for the day
4. Instead of limiting your eating window, eliminate grazing
   1. If IF does not work for you, start with prioritizing 3 full meals per day and eliminate grazing in between meals. 1-2 snacks per day are okay to incorporate, but work to avoid continuous eating. Ideally, meals should be large enough to keep you full for 3-4 hours. Snacks should keep you full for 1-2 hours. 

Trying IF can be interesting to learn more about what works for your body. However, remember that it does not work for some people and it is not the only way to be healthy! 

Sources:

​​https://pubmed.ncbi.nlm.nih.gov/27062219/

https://www.sciencedirect.com/science/article/pii/S1568163718301478

https://www.nejm.org/doi/full/10.1056/nejmra1905136