There’s been quite a bit of buzz in the health world lately about intermittent fasting (IF). There are claims by some that IF has helped them lose and maintain weight loss, some have noted improvement/reversing of metabolic disorders such as type 2 diabetes/metabolic syndrome, improvement in symptoms in autoimmune disorders (such as RA) or just a general sense of improved sense of health (I personally would fall into the latter group). There are no set guidelines to IF, but there are several common approaches out there in the health world that people often follow.
First, what is intermittent fasting?
- IF is when you go for an extended time between meals. For some people this may be 12 hours and for others this may be 3+ days! For many people who practice IF it may fall somewhere in between this.
Is fasting healthy? Will my body eat up all my muscle tissue and will I wither away to nothing? I thought I was “supposed” to eat every 2-3 hours to “keep my metabolism going”.
- Fasting for extended periods of time can be very beneficial. It “teaches” the body to burn it’s preferred fuel–bodyfat–instead of being carb (aka sugar, glucose) dependent, which is what most people in our society are using as energy and then they can’t tap into their fat stores.
- Most people, including people who are skinny, have plenty of body fat available to use for energy. Fat is very energy dense and this is what our body prefers to use for fuel. It’s slow burning and can sustain us for long periods of time. For thousands and maybe millions of years humans had to hunt and forage for food. This took time, energy and mental clarity. There weren’t kitchens stocked with sugar and carb laden snacks at arms reach. There weren’t fast food restaurants and convenience stores with cheap food and 44 oz sodas on every corner.
- The last 20-30 years the fitness and nutrition industry has promoted eating every 2-3 hours to “keep my metabolism going”. This has only created a dependence on cheap sources of fuel (high glycemic carbs and processed foods) and our nation sure isn’t getting any thinner and there is increased incidence of metabolic disease like type 2 diabetes. Eating that often and being carb dependent creates a huge insulin burden. You eat the snack–blood sugar increases–pancreas secretes insulin–blood sugar goes down–you are hungry again. Repeat cycle. Do that for an extended period of time and bad things happen, the main ones being weight gain and insulin resistance. If your body is exposed to insulin constantly then the insulin receptors will eventually become more “resistant” to the insulin and now you have the beginning stages of type 2 diabetes. In addition, insulin is a very powerful hormone that, in the right amounts is absolutely healthy, but in too high amounts can contribute to insulin resistance and weight gain as too much insulin can drive fat storage and wreak havoc in the body and cause inflammation! Inflammation is the precursor to all sorts of acute and chronic disease processes.
Potential benefits of Intermittent Fasting:
- “Teaches” your body to burn it’s own bodyfat (who doesn’t want that?!) instead of being carb dependent
- Regulates leptin and ghrelin, which are appetite/hunger and satiety hormones, to healthy levels to keep you from being “hangry” and send normal signals to your brain when you are full.
- Can help you lose and maintain weight loss
- It gives you a new sense of mental sharpness and focus
- As mentioned above, can keep you from being “hangry”. This is important when having a busy day at work or travelling. Instead of eating some cheap snack because of feeling “hangry” you now have the ability to wait until you can have a healthy meal.
- Can help treat metabolic diseases such as type 2 diabetes/metabolic syndrome, can help symptoms of autoimmune disease and other diseases such as neurodegenerative diseases.
- Might help treat or prevent cancer due to autophagy, which is basically the body cleans out, repairs/recycles damaged cells–when you are constantly eating and keeping insulin levels high it is very difficult to do this.
How long do I fast?
- There is really no “right” but potentially some “wrong” when figuring out how long to fast
- First, I recommend fasting only after you have been eating a primal/paleo sort of pattern for about a month or so to prevent the rapid swings in blood sugar that will leave you feeling worse
- If you are used to eating all of the time, start with skipping a meal. For example, if you are used to eating breakfast every day, try skipping breakfast and making it until lunch time.
- The 16/8 principle is quite popular. Basically you fast for 16 hours and have an 8 hour eating window. For example, if your last meal is at 7 pm you would fast until 11 am and your “eating window” would be from 11 am until 7 pm. That seems to work well for a lot of people and that is what I do most days.
- After you’ve adapted to some “short” fasting windows you can experiment with longer fasts, such as a 24 hr+ fast. Be sure to stay hydrated and listen to your body and don’t overdo it.
Who shouldn’t fast?
- I don’t know if there are clear cut rules for this but there are people who need to express caution when fasting or maybe who should not fast at all. Pregnant women may not want to embark on a fasting journey if they have not already been doing it (consult medical provider), diabetics may need to coordinate with their medical provider to prevent low blood sugar from the medications, people who are NOT on a healthy eating plan will likely get really “hangry” and feel like crud, if you are an extreme athlete (marathon runner, crossfitter, etc) you may not do well with prolonged fasting, and, lastly, if you do follow all the fasting “rules” and you just don’t feel good when fasting then don’t do it!
Thoughts? Questions? Please feel free to start a discussion!