By Aaron Boike, B.S. Kinesiology, ACE Certified Personal Trainer
What if limiting your eating to a 12 hour window during the day would stave off obesity, help you become less susceptible to cancer and heart disease, and help maybe even improve your endurance? Would you consider it?
I think the answer for most of us is a resounding “YES!”
Researchers led by Dr. Sachin Panda at the Salk Institute for Biological studies completed a study in 2015, published in the journal for Cell Metabolism, that shows some promising results for including time restricted eating as part of a wellness program. The study was done in mice that were fed various diets; high fat, high fructose, high fat and sucrose, and a regular mouse food kibble. The mice were then divided up into groups that were allowed to eat at all hours, or those that were restricted to a 9-12 hour window. Some of the mice in the “eat anytime” group were shifted to the limited feeding hours group half way through, as well. What the research showed was very compelling. By the end of the 38 week study, mice that were in the “eat anytime” group were ill and obese, showing signs of metabolic disease; a precursor to heart disease. Mice in the restricted eating window groups remained slim and healthy, even in the groups that were given a nutritionally poor diet (the high sugar, high fat groups). The mice that were switched half way through had lost the weight they had gained and reversed obesity. Some of the mice in the restricted eating window group were allowed to “cheat” on weekends and eat outside of their window. The results showed that the mice could get away with cheating and stay lean and fit, as long as they stayed within their restricted eating window the other five days of the week. The group in the nine hour feeding window also showed a marked improvement in their endurance.
The research points to what Dr. Panda refers to as the “circadian clock,” which his research shows applies to more than just your sleeping patterns, but also extends to your metabolic and digestive systems. His research indicates that we may function optimally when periodically deprived of food. While this might seem “unnatural,” many suggest that it is far more natural than our current typical eating pattern. Most individuals eat in a window of 15 or more hours currently, much more than our ancient ancestors likely did. The reasons for this are complex, but it can be assumed that longer work days, longer waking hours, and continuous access to food are all factors that have led to us being more like the “eat anytime” mice. When we’re not sleeping…we’re eating, and with the average individual only sleeping 6-7 hours per night, we’re eating over a longer period of time than ever before. For our predecessors, it is likely that it was quite abnormal for the eating window to exceed 12 hours on a regular basis.
Whats more? There is a wealth of research showing that the body does “housekeeping” during periods of fasting. This housekeeping helps keep inflammation at bay, improves sensitivity to insulin and leptin (the satiety hormone), and causes the body to burn visceral fat, the worst kind of fat for your overall health.
Dr. Panda suggests that the 12 hour feeding window may be a much more easy to follow intervention for those looking to lose weight and improve health than counting calories or making major dietary changes. Although, he is careful to note that the quality and quantity of diet do play an important role in weight and health.
Sources:
Chaix, A., Zarrinpar, A., Miu, P., & Panda, S. (2014). Time-Restricted Feeding Is a Preventative and Therapeutic Intervention against Diverse Nutritional Challenges. Cell Metabolism, 20(6), 991-1005. doi:10.1016/j.cmet.2014.11.001
@. (n.d.). Intermittent Fasting May Be the Key to Healthy Weight. Retrieved October 27, 2016, from http://fitness.mercola.com/sites/fitness/archive/2015/01/30/time-restricted-eating.aspx#!