Intermittent Fasting: The Key to Weight Loss?
It seems like everyone is talking about intermittent fasting and how amazing it is for your health. But is intermittent fasting actually healthy or just the next passing fad diet?
What is intermittent fasting?
Intermittent fasting is a controlled and voluntary cycling between periods of fasting and eating. It is primarily used for weight loss.
Various forms have existed throughout much of human history. It became highly popularized in 2012 by BBC broadcast journalist Dr. Michael Mosley’s TV documentary Eat Fast, Live Longer and book The Fast Diet. Since then, this health trend has been generating a steady and passionate following in the world of wellness.
Is fasting the new calorie-restriction diet?
Intermittent fasting typically results in a decrease in calories consumed. However, this is not the same as an extreme calorie-restriction diet.
Studies repeatedly show that extreme calorie-restriction diets do not work for long-term weight loss. From your body’s perspective, extreme calorie-restriction diets are the equivalent of starvation.
While initial weight loss is seen, people quickly experience rebound weight gain. They also develop a slower metabolism, worsening insulin resistance, and more resistant weight loss next time they try to lose weight.
These side effects increase the likelihood of developing other serious health problems including type 2 diabetes, reduced fertility, and weakened bones.
Extreme calorie-restriction diets are also miserable to be on. First, they make you feel hungry all the time. Then, this naturally leads to “cheating” on your diet. Finally, this brings on feelings of guilt, shame, and failure.
Nothing helpful comes from getting stuck in this cycle!
In contrast, some of the purported health benefits of intermittent fasting include:
- Weight and body fat loss
- Increased fat burning (i.e. faster metabolism)
- Lowered blood insulin and sugar levels
- Reversal of type 2 diabetes
- Improved mental clarity and concentration
- Increased energy
- Increased growth hormone, at least in the short term
- Improved blood cholesterol profile
- Longer life
- Activation of cellular cleansing by stimulating autophagy
- Reduction of inflammation
Is there a right way to do intermittent fasting?
Not all intermittent fasting approaches are equal.
Research by the University of Alabama showed that a form they referred to as “early time-restricted feeding” was the most effective. In this model, all meals were fit into an early eight-hour period of the day, e.g. 7am to 3pm. This study compared the health effects gained over a five-week period as compared to the group eating over a 12-hour period each day.
By using early time-restricted feeding, participants experienced weight maintenance (neither gained nor lost), dramatically lower insulin levels, significantly improved insulin sensitivity, and significantly lower blood pressure. Plus, they had a decreased appetite which means they weren’t starving!
Now, if weight loss is your goal, then this study may not sound successful when considering whether or not to try intermittent fasting. However, the ability to maintain your weight is a necessary step on the path toward weight loss. Remember, we cannot lose weight if we are still gaining it.
Simply by changing the timing of meals significantly benefited the metabolism of people who didn’t lose a single pound. Most people could stick to this approach quite easily by following a 10am to 6pm eating schedule.
Early time-restricted feeding also taught participants to eat only during daylight hours. This naturally helps our bodies stay in sync with our circadian rhythms. Nighttime eating is well associated with a higher risk of obesity and type 2 diabetes.
Dehydration is more common is people practicing intermittent fasting, especially beginners.
If you try intermittent fasting, remember not to also restrict your water intake. It is easy to forget to drink water during hours of fasting.
Should everyone try intermittent fasting?
Even healthy forms of intermittent fasting are not recommended for everyone. Any person that requires a higher caloric intake should avoid any form of fasting.
This includes individuals who are:
- Struggling with weight gain
- Under 18 years of age
- Pregnant or breastfeeding mothers
- Have a history of or are at risk of an eating disorder, such as anorexia or bulimia
Is intermittent fasting safe for patients with type 2 diabetes?
Type 2 diabetes is primarily treated with insulin medication. However, type 2 diabetes symptoms are highly affected by diet.
The BMJ reported a case series which demonstrated that therapeutic fasting was an effective alternate to insulin for the treatment of type 2 diabetes. Patients adopted 24-hour fasting schedules either on alternating days or three times per week.
On fasting days, patients only consumed dinner. On non-fasting days, patients consumed lunch and dinner. Patients were allowed to drink unlimited amounts of very low-calorie fluids during fasting. These included water, coffee, tea, and bone broth. A daily multivitamin supplement was also encouraged.
Patients followed this form of therapeutic fasting for 11 months. All participants achieved a reversal of insulin resistance and discontinuation of insulin medication using this more extreme form of intermittent fasting.
The minimum number of days on this diet it took for patients to be able to discontinue the use of insulin was only five days. The maximum was 18 days. That’s truly amazing!
As a result of this, albeit small, study (there were only three patients) it appears that a combination of intermittent fasting and a low carbohydrate and low sugar diet may be an effective treatment for type 2 diabetes.
Despite these dramatic results, experts urge patients with type 2 diabetes not to try therapeutic fasting on their own. Fasting for a patient with diabetes is potentially dangerous. It can increase the risk of hypoglycemia during fasting and binge-eating when they resume eating.
If you have advanced diabetes or are on medication for diabetes, then it is essential that you work closely with your doctor while practicing any form of fasting. Your health and medication dosage will need to be closely monitored.
Is intermittent fasting the key to weight loss?
If sustainable weight loss is your goal, then it takes more than simply restricting the times of day you eat to be healthy. You still need to eat a nutritious diet, stay well hydrated, engage in the right forms of physical activity for your body, get enough sleep, and effectively manage your stress.
Discovery Contributor. (2019, October 22). The Dangers of Intermittent Fasting. Retrieved from https://centerfordiscovery.com/blog/the-dangers-of-intermittent-fasting/
Fung, J. (2016, January 28). Intermittent Fasting for Beginners. Retrieved from https://www.dietdoctor.com/intermittent-fasting
Furmli, S., Elmasry, R., Ramos, M., & Fung, J. (2018). Therapeutic use of intermittent fasting for people with type 2 diabetes as an alternative to insulin. BMJ Case Reports. doi: 10.1136/bcr-2017-221854
Scher, B. (2018, October 17). Intermittent fasting – the best diet for type 2 diabetes. Retrieved from https://www.dietdoctor.com/intermittent-fasting-the-best-diet-for-type-2-diabetes
Sutton, E. F., Beyl, R., Early, K. S., Cefalu, W. T., Ravussin, E., & Peterson, C. M. (2018, May 10). Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes. Retrieved from https://www.sciencedirect.com/science/article/pii/S1550413118302535
Tello, M. (2020, February 10). Intermittent fasting: Surprising update. Retrieved from https://www.health.harvard.edu/blog/intermittent-fasting-surprising-update-2018062914156
Disclaimer: I am not a doctor. This blog post is general information only and is not to be substituted for medical advice, diagnosis, or treatment.