Fasting has increased a lot in popularity, especially for weight loss purposes. Fasting can offer many other health benefits though, such as improving metabolic health, brain function, gut health, physical performance, sleep, spiritual health, increasing the ability to handle stress by making cells more resilient, preventing many diseases, and much more. Of course the benefits depend on how long and how often you are fasting.
Fasting literally means going without, so ideally when fasting you are not consuming anything other than water.
However, this depends on your goals for practicing fasting and can vary considerably. For example, many people consume coffee, tea, and fats such as MCT oil and butter and still see the benefits of fasting.
So can you use fasting to lose weight? A new study recently came out in the New England Journal of Medicine comparing types of intermittent fasting (IF), which means to limit your daily eating window to certain hours. For example, you might fast for 14 to 16 hours and eat all of your meals within an 8 to 10 hour window.
The study compared intermittent fasting to a normal calorie restricted diet that you might follow for weight loss and concluded that there are no significant benefits from either approach, including no big changes on the scale weight and in body fat.
This could well be true, because ultimately it is your calorie intake compared to how many calories your body needs that will determine weight loss. If an individual consumes a higher calorie intake than their body needs then that could even lead to weight gain.
However, we should not forget the many benefits of intermittent fasting, other than weight loss. Some individuals might find it much easier to follow a diet in a restricted eating window, and especially if the person’s diet requires low calories then it can be helpful to eat only two meals a day within a shorter eating window than 5-6 smaller meals a day.
So intermittent fasting really is just a way of eating. I personally experience that when I am on a diet it is easier to eat during specific hours — I just fit it into my schedule and I find I’m not thinking about food the rest of the time.
However, some people struggle with it, maybe they feel too hungry or for another reason a simple calorie restriction diet suits them better. Ultimately the calories do matter, so whether or not you are practicing intermittent fasting you still need to watch how many calories you are consuming. Intermittent fasting does not mean that when you are eating you just eat whatever you want. If that’s how you feel then probably you’ll see better results by restricting your calories.
No, intermittent fasting is not a magical solution for weight loss but it can be a great strategy for many people who want to lose weight. Also, you are getting so many other health benefits.
To quote author and scientist Mark Mattson in his book “The Intermittent Fasting Revolution: The Science of Optimizing Health and Enhancing Performance,” “Intermittent fasting is not the latest fad diet; it doesn’t dictate food choice or quantity. It doesn’t make money for the pharmaceutical, processed food, or health care industries. Intermittent fasting is an eating pattern that includes frequent periods of time with little or negligible amounts of food. It is often accompanied by weight loss, but, studies show that its remarkable beneficial effects cannot be accounted for by weight loss alone.”
Resources:
• “Calorie Restriction with or without Time-Restricted Eating in Weight Loss”; https://pubmed.ncbi.nlm.nih.gov/35443107/
• “Calorie Restriction with or without Time-Restricted Eating in Weight Loss”; https://www.nejm.org/doi/10.1056/NEJMoa2114833
• “Fasting challenges human gut microbiome resilience and reduces Fusobacterium”; https://www.sciencedirect.com/science/article/pii/S2590097819300035
• “Changes in human gut microbiota composition are linked to the energy metabolic switch during 10 d of Buchinger fasting”; https://www.cambridge.org/core/journals/journal-of-nutritional-science/article/changes-in-human-gut-microbiota-composition-are-linked-to-the-energy-metabolic-switch-during-10-d-of-buchinger-fasting/1E4307FAFD57B566BE13193A09037673
• “Fasting alters the gut microbiome reducing blood pressure and body weight in metabolic syndrome patients”; https://www.nature.com/articles/s41467-021-22097-0
• “The Effects of Intermittent Fasting on Brain and Cognitive Function”; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8470960/
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Ayda Ersoy is a nutritionist (Dip.C.N., Dip.S.N.); master trainer (CPT ACE, NCSF, CanfitPro); registered yoga teacher; founder, Health Angel Nutrition, Fitness and Wellness; and founder, SMS (Stability, Mobility Strength) Intuitive Training System.
