Author: Alison MacPhee
Introduction to Intermittent Fasting
Dieting and nutrition have become widespread topics discussed in today’s society. There is almost an endless list of different diets and regimens that people use, with one of the most popular being intermittent fasting . In fact, a 2018 survey found that “of the 36% of Americans that followed a specific diet, 10% chose intermittent fasting” . This is largely due to the nature of the diet; the fact that it emphasizes the timing of one’s eating rather than the types of foods being eaten makes it appealing to those seeking a dieting method [1,3].
Intermittent Fasting Methods
Another appealing aspect of intermittent fasting is that there are a few different methods people can choose to follow, depending on what suits their lifestyle. The most common method is called the 16:8 method, which involves fitting all one’s meals into a consistent 8-hour period of the day, every day, while the other 16 hours are reserved for fasting [1,4-6]. During fast periods, one is permitted to drink water, tea, coffee, and other low-calorie beverages with no added sugar [1,5]. The timing of these 8-hour periods is crucial, as our body has evolved to adapt to a circadian rhythm, in which nighttime is reserved for sleep and daytime is a time for food processing . Snacking or eating at night is not recommended, and higher rates of obesity and type-2 diabetes are associated with these activities . Instead, earlier times (e.g. 7am-3pm, 10am-6pm, etc.) are recommended, if possible . This way, most of the fast happens overnight .
Other methods of intermittent fasting include the 5:2 diet, where one eats normally for five days per week, while the other two days are non-consecutive, 24-hour fasting periods [1,4-6]. During these fasting periods, women usually eat a 500-calorie meal at lunchtime, while men eat 600 calories [1,4-6]. It is also possible to have these two fast days be complete fasts with no food whatsoever, but it depends on the person’s body and lifestyle [1,4-6].
How Does Intermittent Fasting Work & What Are the Benefits?
When you eat, your body runs on those calories to keep it going [2-4]. If someone constantly snacks throughout the day, the body only burns those snacks’ calories and does not dip into its stored fat reserves [2-4]. On the other hand, during the fasting periods of an intermittent fasting diet, the body finishes burning snacks’ calories and sugars, and then starts to burn fat for energy [2-4]. Although it may sound intense, many studies show that because fasting puts your cells under minor stress, your cells actually become better adapted to dealing with stress, and in turn, better at fighting diseases . In addition, the human body we are familiar with today has evolved from a hunter-gatherer lifestyle from thousands of years ago, where it was sometimes a struggle to find food [1,4]. Therefore, the body is able to handle going longer periods of time, to a certain extent, without a caloric intake [1,4].
Although research about the benefits of intermittent fasting is still in its early stages, studies have shown that it does provide desirable effects for many people [1,2,4-6]. These include better heart health, brain health, cancer prevention, and an extended lifespan [1,4]. More specifically, it increases Human Growth Hormone (HGH) levels, which promotes fat loss and muscle gain, as well as improved insulin sensitivity, which makes “stored body fat more accessible” . Overall, it has so far proved to be a reputable diet strategy for many people.
Risks and Downsides of Intermittent Fasting
Like any diet, intermittent fasting may come with its risks and side effects, and it may not be for everyone. When starting this diet, it is normal to take 2-4 weeks to adapt, and in this time frame, one may experience symptoms of hunger or crankiness . It is not recommended to continue with it if one experiences more severe side effects that impact daily life, such as anxiety, nausea, headaches, depression, or altered menstrual cycles [2,4,6]. It is also discouraged for children and teens, people with diabetes, people with a history of eating disorders, pregnant individuals, etc., and they should consult a doctor before beginning any sort of diet [1,3,4,6]. Research has also shown that it may be more effective for overweight people compared to those with a lower weight . However, the reason behind this is still unclear . Due to the nature of this diet and the high emphasis on timing, it may also interfere with some social activities that revolve around food or drinks .
In general, everyone’s body is different, and what works for one person may not work for someone else [1,2]. If someone seeks a diet, it is important for them to personally find what works best for them and their lifestyle in order to see the best results [1,2]. After all, as many dieticians and physicians say, “the best diet is one you can stick to” .
Jasmine Kokkat, Rhea Verma
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