The Skinny on Intermittent Fasting and 8 Benefits Backed by Science
“Fasting” recently went from being a big “no-no” (gotta eat every 2 hours) to the hot new thing in health.
Everyone seems to be on some fasting protocol. If you have been thinking about getting on the fasting train or just are curious what everyone is talking about, I’m going to break it down for you.
Intermittent fasting (IF) is about sprinkling in short periods of time where you do not eat. Three common fasting protocols include:
1) Fasting for a full 24 hours once or twice a week
2) Reducing your caloric intake every other day
3) Fasting for 16 hours for every 24 hour period (which is my favorite and I will expand on in this blog).
All three are great options depending on your lifestyle, but it is always recomended to consult your doctor. For anyone who may have a history of eating disorders fasting may not be the best idea so definitely consult with a health professional first.
8 Benefits Backed by Science
1) Increase metabolism: Fasting for short periods has been found to increase your metabolism, compared to fasting for long periods of time which often slows it down (Mansell & Macdonald, 1990; Müller et. al., 2015; Nair et. al., 1987; Webber, et al., 1994).
2) Disease reduction: IF has the potential to reduce diseases such as diabetes and cardiovascular disease (Anson et al., 2003; Wan et al., 2003). In many studies, implementation of the IF dietary regime results in an approximately 20–30% reduction in caloric intake over time.
3) Keep the brain healthy: Fasting has been found to protect against neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. (Martin et al, 2006)
4) Anti-aging qualities: IF has been found to enhance autophagy, a response present in all of our cells to basically clean out and recycle (Bergamini, Cavallini, Donati, & Gori, 2007). This is an essential part of the anti-aging mechanism of caloric restriction. IF bumps the autophagic response giving your cells time to get DNA waste out which is the most robust anti-aging intervention known so far.
5) Give your digestive system a break: IF gives your overworked digestive system a much-needed rest for recovery and repair.
6) Optimize gut health: Yep, we are talking about the microbiome, the collection of trillions of bacteria living in and on our body. IF gives your gut microbes a break from digestion and increase the diversity of your gut bacteria boosting immunity and overall health (Zarrinpar et. al., 2018)
Researchers have also found that daily fasting activates a gene that strengthens the gut barrier protecting us from harmful microbes, toxins, and other substances (Shen et. al., 2016)
7) Target fat burn: Restricting food to a specific time period during IF reduces how often you raise insulin levels, therefore encouraging your fat cells to release fat for fuel.
8) A new relationship with food: Are you often eating out of habit? Do you eat breakfast when you are not hungry? Are you fitting in six meals a day only because you were told that is what is best for your health? Some people who practice IF find that it allows them to take a step back, reassess and even begin to understand their relationship with food.
For many people, including myself, our food habits have become an obsession.
The same way it is healthy to unplug from obsessively checking our phones IF allows you to "unplug" from our obsession with food. The reality is the skipping a meal every once in a while is not bad for you.
I have found that my anxiety around food has decreased and am actually able to focus more throughout the day and enjoy my food when the time comes to break my fast.
One of the most important things to remember is that INTERMITTENT FASTING is NOT CALORIE RESTRICTION.
The best part about IF is that you eat normally during your "feed times" (that's what I like to call my eating windows). No more feeling like lunch has to be a tiny little meal and no more counting calories. Eat healthy, balanced meals as you would normally and enjoy them!
Anson RM, Guo Z, de Cabo R, Iyun T, Rios M, Hagepanos A, et al. Intermittent fasting dissociates beneficial effects of dietary restriction on glucose metabolism and neuronal resistance to injury from calorie intake. Proc. Natl. Acad. Sci. U.S.A. 2003;100:6216–6220.
Bergamini, E., Cavallini, G., Donati, A., & Gori, Z. (2007). The Role of Autophagy in Aging: Its Essential Part in the Anti-Aging Mechanism of Caloric Restriction. Annals of the New York Academy of Sciences, 1114(1), 69-78. doi:10.1196/annals.1396.020
Mansell, P., & Macdonald, I. (1990). The effect of starvation on insulin-induced glucose disposal and thermogenesis in humans. Metabolism, 39(5), 502-510. doi:10.1016/0026-0495(90)90009-2
Martin, B., Mattson, M. P., & Maudsley, S. (2006). Caloric restriction and intermittent fasting: Two potential diets for successful brain aging. Ageing Research Reviews, 5(3), 332-353. doi:10.1016/j.arr.2006.04.002
Müller, M. J., Enderle, J., Pourhassan, M., Braun, W., Eggeling, B., Lagerpusch, M., . . . Bosy-Westphal, A. (2015). Metabolic adaptation to caloric restriction and subsequent refeeding: The Minnesota Starvation Experiment revisited. The American Journal of Clinical Nutrition, 102(4), 807-819. doi:10.3945/ajcn.115.109173
Nair, K. S., Woolf, P. D., Welle, S. L., & Matthews, D. E. (1987). Leucine, glucose, and energy metabolism after 3 days of fasting in healthy human subjects. The American Journal of Clinical Nutrition, 46(4), 557-562. doi:10.1093/ajcn/46.4.557
Shen, R., Wang, B., Giribaldi, M. G., Ayres, J., Thomas, J. B., & Montminy, M. (2016). Neuronal energy-sensing pathway promotes energy balance by modulating disease tolerance. Proceedings of the National Academy of Sciences, 113(23). doi:10.1073/pnas.1606106113
Wan R, Camandola S, Mattson MP. Intermittent food deprivation improves cardiovascular and neuroendocrine responses to stress in rats. J. Nutr. 2003;133:1921–1929.
Webber, J., & Macdonald, I. A. (1994). The cardiovascular, metabolic and hormonal changes accompanying acute starvation in men and women. British Journal of Nutrition, 71(03), 437. doi:10.1079/bjn19940150
Zarrinpar A, Chaix A, Xu ZZ, Chang MW, Marotz CA, Saghatelian A, Knight R, Panda S. Nature Communications. 2018 Jul 20; 9: 2872