Intermittent Fasting
Intermittent fasting has caused some hype through the media of late and it could be considered a new weight loss fad. Studies are starting to appear as to whether intermittent fasting is any better or worse than counting calories.
Intermittent energy restriction (IER) involves restricting energy intake for a predefined period of time and is followed by eating ad libitum within a restricted time frame.
Intermittent fasting is divided into two subcategories:
1. Alternate days of fasting usually between 1-4 days, or the 5:2 day fasting regime
(5 days of eating, 2 days of fasting) or
2. Fasting every day (24 hours) for a set period of time such as 16/8, 12/12 or 20/4 hours.
Intermittent fasting was created as an alternative to calorie restriction in order to improve compliance. Intermittent fasting allows a “feed day or time” where you can eat without having to count calories. It appears that this method has a better adherence rate and it is easier to adapt to over a shorter period without any impact on energy levels on the fast days.
Calorie restriction
Calorie restriction has historically shown in both animal and human studies the ability to reduce insulin sensitivity, reduce blood pressure and heart rate, reduce oxidative stress, lower rates of kidney disease, decrease neurological degeneration and improve reproductive function.
Intermittent Fasting
Human clinical trials have showed that intermittent fasting can lead to significant reductions in body weight and adiposity (fat) either comparable to or greater than using calorie restriction.
Studies are also showing that intermittent fasting can improve the parameters for type 2 diabetes and glucose tolerance, weight reduction, cardiovascular health and reduction in cholesterol. Some of these effects are greater for women than for men.
Conclusion
There have been some questions around eating excessively on the feed days and how this may impact the desired outcomes. What has been discovered is that after a fast day there is a reduced energy intake up to 25%, so even though you may eat as you want your body has a reduced need which then allows for greater weight reduction.
So more importantly which one is better? Well, neither is better or worse, just another option for weight management. Both have good health benefits associated with them. But as a naturopath, I can say there is not one diet regime that suits everyone. Therefore the best diet would depend on the individual person and the conditions they present with.
So if you want to know more or this is of interest to you book in to see me.
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This article was written by Jan Caton who holds a Bachelor of Health Science. Jan is the Director of Magnolia Apothecary and a practicing Naturopath, Nutritionist and Herbalist, based in the Yarra Ranges.
References
Gabel, K., Hoddy, K. K., Haggerty, N., Song, J., Kroeger, C. M., Trepanowski, J. F., Varady, K. A. (2018). Effects of 8-hour time restricted feeding on body weight and metabolic disease risk factors in obese adults: A pilot study. Nutrition and Healthy Aging, 4(4), 345–353. https://doi.org/10.3233/NHA-170036
Harvey, J., Howell, A., Morris, J., & Harvie, M. (2017). Intermittent energy restriction for weight loss: Spontaneous reduction of energy intake on unrestricted days. Food Science & Nutrition, 6(3), 674–680. https://doi.org/10.1002/fsn3.586
Harvie, M. N., Pegington, M., Mattson, M. P., Frystyk, J., Dillon, B., Evans, G., Howell, A. (2011). The effects of intermittent or continuous energy restriction on weight loss and metabolic disease risk markers: a randomized trial in young overweight women. International Journal of Obesity, 35(5), 714–727. https://doi.org/10.1038/ijo.2010.171
Klempel, M. C., Kroeger, C. M., Bhutani, S., Trepanowski, J. F., & Varady, K. A. (2012). Intermittent fasting combined with calorie restriction is effective for weight loss and cardio-protection in obese women. Nutrition Journal, 11, 98. https://doi.org/10.1186/1475-2891-11-98