Intermittent fasting might be trending on social media today, but this way of eating – or not eating – is hardly the trendy new diet plan.
For thousands of years, people have fasted. In recent years, the focus of fasting has shifted to its many healthy benefits, including weight loss and lowering your risk of diseases like diabetes. (1)
One thing I love about intermittent fasting is that it puts the brakes on the constant grazing cycle that keeps insulin levels jacked up and stalls fast loss.
We’ve only had access to the massive amounts of food that allow us to snack from morning to night for about 200 years. Not surprisingly, researchers have connected the rise in obesity and other metabolic diseases with our ability to graze all day. (2)
Intermittent fasting puts the brakes on grazing to give your digestive system a much-needed break. Every day, we’re learning more about how fasting can benefit your gut, waistline, and so much more.
Intermittent Fasting: An Alternative to Counting Calories
Numerous studies have shown that caloric restriction, or lowering your calorie intake to a healthy level, can extend lifespan in humans. But let’s be honest. While it may work initially, caloric restriction is neither easy nor practical for most people.
For decades, I’ve told clients and readers to stop counting calories. Your body is not a savings bank or a calorimeter. It’s a chemistry lab. Although the total number of calories counts, it is only part of the story. The source of the calories matters far more.
That’s where intermittent fasting comes in. It gives you all the benefits of caloric restriction without monitoring calories or otherwise driving yourself crazy counting! (3)
What Is Intermittent Fasting?
I’ve been aware of the buzz surrounding intermittent fasting for quite a while. I really became interested a few years ago, though, after my son Grant suffered a traumatic brain injury during a hit-and-run accident.
I researched several options to help him recover from his injuries. It turns out that intermittent fasting combined with a ketogenic diet were powerful therapies that helped his brain heal. (4)
Simply put, intermittent fasting alternates periods of fasting or not eating with periods of eating. That said, there are many, many types of fasting.
Some of them are fairly conventional, such as eating zero calories during your eating hours. Others, such as my pal Dave Asprey’s Bulletproof™ intermittent fasting, involves starting your day with a creamy cup of Bulletproof™ coffee.
A few popular fasting plans include:
- Alternate-day fasting (where you fast one day and then eat normally the next)
- The 16/ 8 plan (where you fast for 16 hours and eat within an 8-hour window)
- The 5:2 plan (where you eat normally 5 days of the week and restrict calorie intake to 500 – 600 calories for the other 2 days)
In my next blog, I’ll go into these plans in more detail, showing you how to incorporate them with The Virgin Diet or Sugar Impact Diet. Together, these plans will help you optimize all of the amazing benefits of intermittent fasting.
7 Benefits of Intermittent Fasting
When you abstain from eating for certain periods of time, certain metabolic changes occur in your body. One of them is a switch from glucose (sugar) to ketones as the body’s primary fuel. This metabolic switch improves brain energy, reduces appetite, and so much more! (5)
Here are 7 of those many, many health benefits that intermittent fasting creates:
- Stress management. Nearly everyone I know these days is dealing with the impact of pandemic stress. Intermittent fasting may help. Studies show that fasting is excellent for brain health by regulating inflammatory pathways and improving the effects of stress. (6)
- Weight loss. One comprehensive review of 27 small, short-duration trials looked at how intermittent fasting helped weight loss in overweight and obese patients. The results were promising: All 27 trials showed weight loss of up to 13 percent. (7)
- Immune health. Several clinical settings have shown that intermittent fasting can support the immune response. One of fasting’s benefits is autophagy, a “spring cleaning” that removes old, damaged cells to make room for healthy new ones. Among its benefits, autophagy boosts immunity. It works so well, in fact, that scientists believe that intermittent fasting is a “promising preventative approach against COVID-19.” (8)
- A longer, healthier life. Studies show that intermittent fasting gives you all the longevity benefits of caloric restriction, without the hassles. (9) Regularly fasting supports autophagy to allow your cells to detox, repair, and recycle. As a result, intermittent fasting slows down aging and age-related diseases.
- Inflammation. Chronic inflammation plays a role in nearly every disease on the planet. (10) It’s a surefire way to stall fat loss, too. Studies show that fasting lowers inflammation and the risk of inflammatory diseases, without suppressing the immune system’s ability to fight infections. (11)
- Heart health. Cardiovascular disease is the leading cause of death worldwide. Research shows that intermittent fasting might prevent cardiovascular disease in several ways, including helping people lose weight, maintaining a healthy lipid profile, and supporting gut health. (12)
- Insulin sensitivity. Insulin resistance happens when your cells can’t “hear” the signal of excess insulin. As a result, your insulin receptors stop responding to the insulin, and your blood sugar remains high. Insulin resistance makes weight loss nearly impossible. Intermittent fasting can improve how your body handles glucose. As a result, fasting can improve insulin resistance. (13)
Not So Fast: It Isn’t For Everyone
Not everyone does well on a fasting plan, and some people should absolutely not fast. According to Jason Fung, MD, in The Complete Guide to Fasting, people who should not fast include:
- Those who are severely malnourished or underweight
- Children under 18
- Pregnant women
- Breastfeeding women
Others should proceed very cautiously about fasting, including people:
- With gout
- Taking medications
- With type 1 or type 2 diabetes
- With gastroesophageal reflux disease
For those people, Fung recommends talking with your healthcare practitioner. I would ditto that for everyone before starting an intermittent fasting plan.
Many people have asked me whether the rules of intermittent fasting are different for women. In my experience, some females do better than others fasting.
Research has shown that fasting may improve reproductive and mental health as well as improve certain cancers and musculoskeletal disorders that are common in middle-aged and elderly women. (14)
But not everyone gets great results. For some women, intermittent fasting may mess with hormones, or otherwise be counterproductive or harmful. Your mileage will vary. Again, proceed cautiously.
If you’re ready to give fasting a go, my next blog will show how to do it intelligently, so you get all of the gains and none of the drawbacks. I’ll talk about how to create a plan that works for you. And I’ll discuss obstacles that you might encounter along the way, how to crush hunger and cravings, and much more.
Armed with this information, you’ll have everything you need to transition smoothly into an intermittent fasting plan.
- Patterson RE, Laughlin GA, LaCroix AZ, et al. Intermittent Fasting and Human Metabolic Health. J Acad Nutr Diet. 2015;115(8):1203-1212. doi:10.1016/j.jand.2015.02.018
- Kang SH, Park YS, Ahn SH, Kim HH. Intermittent Fasting: Current Evidence in Clinical Practice. J Obes Metab Syndr. 2020;29(2):81-83. doi:10.7570/jomes20022
- Hwangbo DS, Lee HY, Abozaid LS, Min KJ. Mechanisms of Lifespan Regulation by Calorie Restriction and Intermittent Fasting in Model Organisms. Nutrients. 2020;12(4):1194. Published 2020 Apr 24. doi:10.3390/nu12041194
Phillips MCL. Fasting as a Therapy in Neurological Disease. Nutrients. 2019;11(10):2501. Published 2019 Oct 17. doi:10.3390/nu11102501
- Wilhelmi de Toledo F, Grundler F, Sirtori CR, Ruscica M. Unravelling the health effects of fasting: a long road from obesity treatment to healthy life span increase and improved cognition. Ann Med. 2020;52(5):147-161.
Shojaie M, Ghanbari F, Shojaie N. Intermittent fasting could ameliorate cognitive function against distress by regulation of inflammatory response pathway. J Adv Res. 2017;8(6):697-701.
Welton S, Minty R, O'Driscoll T, et al. Intermittent fasting and weight loss: Systematic review. Can Fam Physician. 2020;66(2):117-125.
- Hannan MA, Rahman MA, Rahman MS, et al. Intermittent fasting, a possible priming tool for host defense against SARS-CoV-2 infection: Crosstalk among calorie restriction, autophagy and immune response. Immunol Lett. 2020;226:38-45. doi:10.1016/j.imlet.2020.07.001
Hwangbo DS, Lee HY, Abozaid LS, Min KJ. Mechanisms of Lifespan Regulation by Calorie Restriction and Intermittent Fasting in Model Organisms. Nutrients. 2020;12(4):1194. Published 2020 Apr 24. doi:10.3390/nu12041194
Furman D, Campisi J, Verdin E, et al. Chronic inflammation in the etiology of disease across the life span. Nat Med. 2019;25(12):1822-1832. doi:10.1038/s41591-019-0675-0
Jordan S, Tung N, Casanova-Acebes M, et al. Dietary Intake Regulates the Circulating Inflammatory Monocyte Pool. Cell. 2019;178(5):1102-1114.e17. doi:10.1016/j.cell.2019.07.050
Allaf M, Elghazaly H, Mohamed OG, et al. Intermittent fasting for the prevention of cardiovascular disease. Cochrane Database Syst Rev. 2019;2019(11):CD013496. Published 2019 Nov 30. doi:10.1002/14651858.CD013496
Cho Y, Hong N, Kim KW, et al. The Effectiveness of Intermittent Fasting to Reduce Body Mass Index and Glucose Metabolism: A Systematic Review and Meta-Analysis. J Clin Med. 2019;8(10):1645. Published 2019 Oct 9. doi:10.3390/jcm8101645
- Nair PM, Khawale PG. Role of therapeutic fasting in women's health: An overview. J Midlife Health. 2016;7(2):61-64.