Let's be honest: The word "hungry" does not exactly convey delicious thoughts and positive vibrations. For many people, this probably creates images of hunger and deprivation and causes their stomach to growl.
However, periodic fasting has so many people swelling at the moment, blabbering about how strict and planned nutrition plans have helped them lose weight and improve their health. So there must be * some * good health and weight loss fad, right?
MD Charlie Seltzer, Weight Loss Doctor and Certified Personal Trainer, states that what most people do nowadays is not “real” fasting (in other words, eating only one meal a day or nothing daily period). Instead, they have periodic fasting (duh), which means they take a diet approach that involves limiting calorie intake to a fixed amount of time each day, from only 1
The logic behind periodic fasting as a weight loss approach: "Because you need to have a calorie deficit to lose weight, eating in the window makes it easier to eat less and reach your calories," Selzer River.
Constant starvation has some benefits besides weight loss, says Dr. Selzer. It works with many people's lifestyles, allowing them to skip meals during the day when they are busy or not very hungry, otherwise they can simply feed off of debt. What's more, following a 5: 2 fasting scheme can even improve your heart health; Starvation can lower blood pressure and bad cholesterol, according to Cleveland HeartLab.
"True starvation has a wide variety of health benefits other than caloric restriction," adds Dr. Selzer. "This can cause cellular autophagy, in which our cells feed on themselves [to destroy damaged cells and make way for new, healthy ones]."
That said, periodic fasting should not be tried without thinking if it is really a good idea for your personality and lifestyle – and not only because it can be challenging to stick to, but also because it can be downright bad for some groups of people.
Registered Dietitian Barbie Boules of Barbie Boules Longevity Nutrition says that people who should not consider fasting periodically are:
- People with diabetes or other metabolic disorders
- People taking medications that require food
- ] Anyone with a history of malnutrition
- Women who are pregnant or trying to conceive
- Children and teens
But honestly, anyone who needs consistent and healthy calorie intake throughout the day for being healthy (physically * and * emotionally!) is not the ideal candidate to drink ate with periodic starvation. If you are not sure where you stand, it is always wise to speak with a healthcare professional first.
Here are eight potential drawbacks, side effects, and direct warnings for periodic fasting to keep in mind if you are a healthy adult and think about trying it yourself.
1. You may feel hungry.
Surprise, Surprise: Not eating 16 hours a day can make you hungry for at least as long as you are in correction.
In theory, says Dr. Selzer, intense starvation should not occur during periodic fasting, using a plan such as the 16: 8 method; if you are fasting by filling up protein at the end of the day, you should not be hungry the first thing in the morning. (Your appetite will not start until the next day.)
In fact, it may take a little while. "The main concern is to deviate from eating behavior because you are so hungry that you eat 5000 calories [and going way over your daily amount]," explains Dr. Selzer.
In other words, just eating in a short window is not a free pass to set up a buffet camp for all you can eat, which would defeat the purpose of fasting. And this can be a huge challenge for many people who are accustomed to eating much more regularly and who may not be in full compliance with their body's hunger.
2. It can make you feel sick or tired in the morning, especially if you exercise first.
Committed to your 6:00 workout? Permanent starvation may not be a great option. "I think it's a terrible idea to exercise on an empty stomach," Bulls says. "We use some glucose before and some protein after."
If you are interested in experimenting with periods of fasting and training in tone, consider talking to a sports nutritionist or doctor to evaluate your training schedule and level of rigor. You may be hungry for a certain amount of time, such as on days when you do not exercise. But if, for example, training for an endurance event, recharging your body around the clock and getting significant calories, it will be much more important than trying to force fasting into your routine when your body is already undergoing your training.
And even if you are not in the morning workout, you don't eat until, say, at lunch, when you are used to waking up and having breakfast at 8 in the morning, it can leave your stomach breasting. For your part, you may feel distracted, lightheaded or nauseous as you get used to the new schedule.
3. Fasting diets are firm and rule based.
Both Dr. Selzer and Bulls describe periodic fasting as very individualized, meaning that it can work well for some people and become a complete disaster for others depending on a number of lifestyle factors.
Boules says that people who "like the rules" can respond to a calorie-limiting diet. But for others – like traveling five days a week, often changing time zones or schedules – dieting will bring more stress than weight loss or other potential health hazards. If the idea of looking at your eating permit watch sounds unattractive, wait for it.
4. This does not always play well with other diets.
Boules says that periodic fasting is often combined with other restrictive diets, such as keto, which can cause double problems if either of these approaches – or forget the sky – is not appropriate for you.
Adopting a diet plan that means you can eat lean protein and vegetables between the hours of 1am and 9am every day does not exactly determine you for winning any popularity contests with your friends and family ( not to mention the mental fatigue that comes with regularly skipping meal planning hoops), Boules points out.
But hey, your choice for a diet is yours and if you are challenged to navigate an intense and strict diet routine and your personal life, this is entirely your decision.
5. You can handle low blood sugar.
That is why people with diabetes should be guarded against fasting. Low blood sugar or hypoglycaemia is a side effect of diabetes and insulin medication, but it can also happen to non-diabetics (if you have a thyroid disease, for example).
Inadequate eating and omission of food are common causes of hypoglycemia. So "people who are prone to hypoglycaemia may feel dizzy or have nausea or shaking," Dr. Selzer warns.
Other symptoms of mild to moderate hypoglycaemia include headache, blurred vision, sweating, fatigue and pallor, according to the National Institute of Diabetes and Digestive and Kidney Diseases.
6. The survey is minimal.
See, we all know that the internet is full of so-called health claims made by "experts" on the best diets. And although the field of study on periodic starvation is not empty, Bulls is hesitant to jump on the strip based on what he has seen so far.
"Despite a number of articles citing research, there is strong evidence to support periodic starvation.
What studies does Boules refer to? Well, most of the more captivating were actually rodent-filled. Human studies have not shown the same scope of evidence.
A Few Examples: A 2018 study published in Nutrition and Healthy Aging showed weight loss results after 12 weeks of 16: 8 periodic fasting – but the sample size was only 23 people. A 2017 study in by JAMA Internal Medicine showed that a fasting group of 100 participants lost more weight over a 12 month period than a non-diet group but no more than a calorie-reducing group generally.
The debate remains whether actual starvation is responsible for the health benefits, or whether it is simply reducing calories.
This does not mean that a better, more definitive study will not ever become available but as Bulls said, we have ways to go before we know everything about periodic starvation.
While Boules acknowledges that periodic starvation can be a great strategy for curbing a senseless late-night breakfast, it can totally work against and eating sensibly. Instead of thinking whether you are really hungry or not, you just eat on the clock.
"I encourage my clients to [evaluate their hunger] daily and act accordingly," she says. "Every day is different for sleep, exercise, stress, hormones and schedules, which affects appetite. This is one of the many reasons I do not believe it is healthy to apply "rules" to your food philosophy.
8. You can take it too far.
Even with diet, moderation is key; no diet is sustainable if you cannot adapt it to your lifestyle as needed. For example, Dr. Selzer emphasizes that many athletes need morning nutrition and see better results when eating before exercise. Keeping to a strict periodic fasting schedule in this example precludes this.
Boules agrees: "I [have seen] people who consume nothing but water before a challenging morning workout and a few hours after that – it's just not a good idea. "
After all, if you're just not sure how to feel during intermittent fasting, don't hesitate to throw it away with a professional, such as an RD or a trusted document.
At the end of the day, if you are a healthy adult, periodic starvation is unlikely to cause harm (even if it proves to be inappropriate for you personally.) Dr. Selzer and Bulls acknowledge the control they teach, although they remain on the fence as to whether potential side effects outweigh
"Please understand that this will not work for everyone and not required for good health, "Bulls says." While looking at the study and owning it, if proven wrong, I think this is another example of a fad for wellness. "