Can I lose weight and promote neuroplasticity?
BY: Frances Villamin
With every new year, there’s a recurring resolution that we tell ourselves: “lose weight!” Henceforth, the booming industry is now all about diets, protein shakes, exercise programs, and of course intermittent fasting. So what is intermittent fasting?
Basically, intermittent fasting is limiting food consumption and calorie-containing beverages to 8 hours a day and fasting in the remaining 16 hours (aka-16:8 fasting clock). You can pick out any 8 hour time window you’d like as your meal time and can experiment which time frame you’d like. Sometimes it’s hard to get the same schedule everyday but for some people they like this strict order. This new diet fad started getting popular in 2012 by BBC broadcast journalist Dr. Michael Mosley’s TV documentary Eat, Fast, Live Longer.
Intermittent fasting can also be called intermittent metabolic switching. When we aren’t eating, our livers are not replenished and so our liver energy stores are depleted causing circulating glucose levels to remain low and adipose cells to release fatty acids. These fatty acids are then converted in the liver to ketone bodies (specifically β-hydroxybutyrate and acetoacetate). This transition from utilization of carbohydrates and glucose (what we gain from eating) to fatty acids and ketones as our fuel source is known as the ‘K-to-G switch’ hence the name intermittent metabolic switching (IMS). The same process happens to someone who is exercising.
But does this diet always work and what are its benefits?
Intuitively, intermittent fasting makes sense when it comes to losing weight. Since the food we eat is broken down by enzymes in our gut, it is eventually ends up as molecules in our bloodstream and broken down sugar for our energy. Sugar can only enter our fat cells with insulin and keeps it there. If we don’t snack and are fasting, our insulin levels will go down → fat cells release our stored sugar for energy → we lose weight by burning off our fat.
Does it always work? — Well, it depends on how you use the information. With any diet or anything in life, if you don’t do it properly then it won’t work. Since humans are in sync with the day/night cycle, our metabolism has adapted for daytime eating and nighttime sleep. So time-restricted feeding to having that 8 hours of meal time to be during the day and fasting at night has definite benefits to it. It has shown beneficial metabolic effects, reduced insulin resistance, and increased glucose tolerance which is all great for your microbiome!
In terms of other benefits, the trending new research right now suggests that intermittent fasting and caloric restrictions can prolong the health-span of the nervous system by affecting the fundamental metabolic and cellular signalling pathways that regulate life-span. Through the repeating cycles of metabolic challenge that induces ketosis (basically fasting) followed by a recovery period (eating, resting, and/or sleeping), affected signalling pathways may promote neuroplasticity and resistance to brain injury and disease. Wow I get to lose weight and improve the resilience of my brain? Sounds too good to be true! Multiple studies has been done to provide conclusions to this thesis and here are the findings we have found:
If you want to try the intermittent fasting challenge here are some advice in optimizing a time-restricted diet²:
- choose the most realistic eating period for you
- aim to stop your evening eating by 9pm (remember our circadian rhythm!)
- stay hydrated with low-calorie beverages
- focus primarily on lean protein on the low-calorie days
- consume a varied diet and be flexible!
Sources:
¹Asher, Gad, and Paolo Sassone-Corsi. “Time for Food: The Intimate Interplay between Nutrition, Metabolism, and the Circadian Clock.” Cell, vol. 161, no. 1, 2015, pp. 84–92., doi:10.1016/j.cell.2015.03.015.
²Fernstrom, Madelyn. “Why Intermittent Fasting May Be the Best Diet for Weight Loss.” TODAY.com, 13 Mar. 2019, www.today.com/health/intermittent-fasting-nutritionist-discusses-methods-weight-loss-t150302.
³Tello, Monique. “Intermittent Fasting: Surprising Update.” Harvard Health Blog, 26 June 2018, www.health.harvard.edu/blog/intermittent-fasting-surprising-update-2018062914156.
⁴Martin, Bronwen, et al. “Caloric Restriction and Intermittent Fasting: Two Potential Diets for Successful Brain Aging.” Ageing Research Reviews, vol. 5, no. 3, 2006, pp. 332–353., doi:10.1016/j.arr.2006.04.002.
⁵Mattson, Mark P., et al. “Intermittent Metabolic Switching, Neuroplasticity and Brain Health.” Nature Reviews Neuroscience, vol. 19, no. 2, 2018, pp. 63–80., doi:10.1038/nrn.2017.156.
