What Are the Pros and Cons of Intermittent Fasting? by Mehdi Yacoubi

What Are the Pros and Cons of Intermittent Fasting?
Posted on
August 16, 2021

Nowadays we hear more about new dietary plans from friends and family than ever before. Some of these plans promise weight loss, while others simply intend to promote a healthier lifestyle. But one eating plan known as intermittent fasting has taken the world by storm in recent years. Its widespread popularity may have you wondering what exactly the pros and cons of intermittent fasting might be and how it can truly impact your health.

Intermittent fasting (IF) looks different for everyone, but the basic premise remains the same. It's the process of cycling between voluntary fasting and non-fasting over a given period of time. Or in other words, limiting the time during which you can eat food on any given day. 

Ongoing research is attempting to fully understand the pros and cons of IF, but maybe you're interested in trying it for yourself. Before you do, let's take a closer look at IF to determine what it is, why it's popular, and how it can impact your life.

What Is Intermittent Fasting?

The purpose of any diet is to achieve a specific goal by restricting or manipulating your eating habits. Sometimes dieting is helpful when you need to lower blood pressure or improve heart health, but it's used extensively when attempting to lose weight as well. The idea is that you consume less food energy during the day than your body burns, thereby creating a calorie deficit that leads to weight loss.

Intermittent fasting achieves this goal by limiting calories during certain days of the week at certain hours of the day. In doing so, the body is supposed to experience decreased appetite by slowing its metabolism

Though different styles of intermittent fasting exist, some are more popular than others. For instance, the 5:2 diet proposes eating normally five days of the week followed by calorie restriction two days of the week. Another popular version of IF suggests no calorie intake each morning for 3-4 hours, followed by normal eating and a strict cutoff point each night. There is no specific intermittent fasting diet that works for everyone, so you may need to try different styles to see what works best for you.

Why Is Intermittent Fasting So Popular?

To understand why intermittent fasting is so popular, we need to look at its appeal as it relates to our overall health. An estimated 45 million Americans adopt a diet each year as a means of losing weight. That's accompanied by the staggering $33 billion spent each year on weight-loss products. 

To that end, intermittent fasting is popular because it's a simple way to lose weight. The meal plan doesn't consist of eating more of food A or eliminating food B. It simply states that you can change your eating patterns to influence your weight without counting calories, restricting food, or investing in dietary plans. Though you should strive to incorporate healthy eating into your life, you can make your own food choices and lead a normal life while losing weight.

What Are the Benefits of Intermittent Fasting?

pros and cons of intermittent fasting: woman happily eating salad

There are many benefits of intermittent fasting that contribute to its popularity. Let's take a look at them in greater detail below.

Easy to Follow

As we've mentioned previously, intermittent fasting is incredibly easy to follow. Unlike other diets that force you to eliminate certain foods or buy into a health plan, IF allows you to eat what you like without taking up too much of your time. 

Unrestricted Eating

One of the biggest complaints people often have with diets is the notion that you have to eliminate foods you enjoy. Maybe that food is unhealthy, like ice cream, but it's also simpler foods like peanut butter, breads, meats, and general comfort foods. IF doesn't limit what foods you eat, only when you can eat them.

No Counting Calories

The idea of counting calories conjures painful memories of checking labels and crunching numbers every single time you eat. Doing so is not only tedious but time-consuming and frustrating as well. When it comes to IF, you don't need to count every calorie. You simply eat fewer calories by implementing fasting periods into your daily life.

Weight Loss

Perhaps one of the biggest health benefits of IF is the weight loss that occurs as a result of all the hard work. A 2018 study that compared IF with other diets found that it results in similar weight loss, especially when it comes to decreasing body fat. It's also efficient in reducing weight, irrespective of the body mass index, over short-term periods.

Other Health Benefits

Though most studies have utilized small testing groups, there's reason to believe fasting can benefit your body in ways beyond weight loss. Researchers from a 2018 study proposed that intermittent fasting could help those with Type 2 diabetes manage their blood sugar through weight loss. 

It may also raise insulin sensitivity in healthy individuals, which is why it's best to speak with a nutritionist or registered dietitian before implementing IF into your life. Insulin sensitivity describes how your body responds to the hormone insulin, and a higher sensitivity allows the cells of your body to use glucose more effectively.  

According to the Cleveland HeartLab, fasting has the ability to lower blood pressure and bad cholesterol (LDL cholesterol) as well.

In addition, a growing body of evidence suggests regular fasting is associated with lower rates of heart failure and a longer life span. This means fasting and caloric restriction may promote longevity as your body adapts to a new dietary regimen. As weak cells die without energy, stronger cells can grow and thrive, improving your chances of a longer life.

What Are the Drawbacks of Intermittent Fasting?

For all the credit we give intermittent fasting, it isn't perfect. Let's take a look at some of the flaws and side effects that come with this popular dietary craze.


It's common for those in the fasting stage of IF to experience severe hunger. This feeling may become more extreme when fasting around others who happen to be eating. The feelings of hunger will lessen over time as you grow accustomed to the process, but don't let hunger become an excuse to eat more when you finally do. After all, there's no sense in eating less during the day only to increase your food intake at night.

Weakness and Fatigue

Your body will need to adjust to your new eating windows, and it may feel weak or sluggish when food isn't available for hours at a time. Consider taking things slow by eliminating food for a small amount of time before eating. For instance, start by eliminating food for 1-2 hours after you wake up before eating a snack or breakfast. From there, increase the time spent fasting in increments to help your body adjust. Jumping into a prolonged window without food can spell trouble for your body if it's unprepared.

Physical Activity Reduction

Most IF programs don't include recommendations for physical activity. That's because any form of strenuous activity can lead to fatigue when combined with a low-calorie diet, though ongoing research is attempting to determine how IF may affect physical activity patterns. If exercise is a pivotal part of your daily life, consider low-intensity exercises when fasting or exercising after a meal to reduce the likelihood of your body breaking down muscle for fuel.

Potential Overeating

There's no sense in heading to the buffet after hours of fasting only to recoup a normal day's worth of calories, but that's exactly what many people do. Overeating may occur if you find yourself attempting to fit your daily caloric intake into one or two meals, but keep in mind that IF reduces your daily intake. Your body needs to operate on fewer calories in order to realize the benefits.

Eating Disorders

Altering your diet in any way can lead to eating disorders in certain individuals. This isn't common, but it's something to consider before IF, especially if you've experienced eating disorders before. Talk to your doctor before incorporating any form of fasting into your life if you have reason to believe it might negatively influence your relationship with eating.

Glucose Levels and Fasting

Years of research have provided us with an established understanding of normal glucose levels, but how do these levels change as a result of fasting? Your blood sugar should fall below 100 mg/dL when fasting for at least eight hours and any reading above this measurement should be addressed with your doctor. Other research suggests those with diabetes may benefit from IF when it’s combined with a healthy diet and lifestyle. The process of eliminating food during specific periods of the day can lead to weight loss, thus reducing the impact of diabetes over time..

Intermittent Fasting and You

pros and cons of intermittent fasting: woman looking at the contents of her fridge

Intermittent fasting is the latest fad diet that promises to improve your overall health by promoting weight loss. It has the potential to positively impact your body, but various drawbacks must be considered before jumping into the diet without a strategy. 

Consider using the Vital app to monitor your blood sugar levels in the absence of food and determine if intermittent fasting is right for you. Doing so will provide you with key insights about your body as you strive to promote a healthy, balanced life.

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