Is the Intermittent Fasting Diet Healthy, Effective, and Safe?

Many people are familiar with the concept of fasting. Whether it’s for religious reasons or to lose weight, humans have been fasting for hundreds of years. In the last decade, a new(ish) weight loss method has been making waves in the dieting community. Intermittent dieting, as it’s called, has been hailed by its supporters as effective and healthy, but so have other fad diets. Is intermittent fasting everything that it’s supposed to be or does it fall short?

How Does the Diet Work?

The basic description of intermittent fasting is perfectly encapsulated within the name — not eating (fasting) for a specific period of time (intermittent). This diet alternates between windows of time spent fasting and windows spent eating. There are several different styles of intermittent fasting that utilize the same principals in different manners.

The three main types of intermittent fasting are:

  • Time-restricted fasting — where you fast except for a specific window of time during the day (usually eight hours, but sometimes more or less)
  • Alternate-day fasting — where you eat normally (or even a little extra) on one day, and fast on the next, only having a small meal of around 500 calories
  • 5:2 fasting — where you eat normally for five days out of the week, but only have one small meal on the other two

Clearly, one of the main benefits of the intermittent fasting diet is calorie restriction. By limiting when you eat, you can effectively cut out snacking. Also, since it’s your only real meal of the day (depending on which type of fasting you go with), you’re more likely to savor and be mindful of the food you’re eating. There are other reported benefits to intermittent fasting, but we’ll get into those later. Right now, we can sum up that the intermittent fasting diet is a method of dietary control by focusing, not on restricting specific foods but, on restricting eating in general, as a way of monitoring caloric intake. While you should still eat healthy during your feast periods, there is less of a focus on what you’re eating, and more on the when.

Is It Safe?

Perhaps one of the biggest concerns one may have about trying the intermittent fasting diet, or any similar diet, is the relationship with fasting. Simply not eating as a way to lose weight can become problematic by having the potential to develop into an eating disorder like anorexia. Beyond that, there is plenty of evidence to suggest that long-term fasting can be incredibly detrimental to your health and isn’t a healthy way to lose weight. It may even be counterintuitive, with some research showing the fasting can slow your metabolic rate. Then, there are also the risks of fasting for specific groups, like pregnant women, people on specific medications, or those with a history of eating disorders, to name a few.

There’s growing evidence that intermittent fasting can have health benefits beyond weight loss.

So, case closed. Intermittent fasting is bad for you, right? Well, there’s an important difference that we need to cover. What we discussed above is the effects of long-term, regular fasting. Intermittent fasting is largely believed to not have these risks (besides the dangers toward risk groups). In fact, there’s growing evidence that intermittent fasting can have health benefits beyond weight loss. For example, there is early evidence that fasting may improve your heart health. Intermittent fasting may also reduce inflammation, which is tied to a number of health complications like cancer, heart disease, and arthritis. This may tie into animal studies that link intermittent fasting with improved brain function and healthier brain aging. In fact, there have been numerous animal studies with promising results toward slowing the aging process and increased longevity. It’s worth noting that these results are promising, but not necessarily definitive yet, with many being in animals. We simply do not fully know the long-term benefits and risks of intermittent fasting in humans yet. That said, these are positive signs moving forward.

Is the Intermittent Diet Effective?

And now, we approach the big question. Is intermittent dieting effective for weight loss? And the answer is a resounding… sort of? Intermittent fasting can help you lose weight. This primarily comes through calorie restriction, but there are other ways that intermittent fasting may aid in weight loss. There is evidence that it may increase your metabolic rate, helping you to burn off fat easier. In fact, there is more evidence that it may target fat cells into releasing insulin to be used as energy, further helping us to lose weight and burn fat.

With all that said, intermittent fasting isn’t any more effective than any other calorie-restrictive diet in terms of weight loss alone. You’ll likely lose weight if you stick to it, but not more than any of the other diets we’ve discussed on Medicareful Living. So, while some people may experience a greater degree of weight loss than others, that can be said for any diet. Then, there’s also the concern with what you’re eating when you’re in the feast phase. If you’re stuffing down sugary and fatty foods, you’ll be worse off than before.

The best way to achieve weight loss is by living a healthy lifestyle that includes a balanced diet that’s simple to stick with.

At the end of it all, is the intermittent fasting diet worth it? It really depends. While there are very promising signs of health benefits beyond weight loss, these are still somewhat disputed or not fully tested in humans for the long term yet. That’s not to say that intermittent fasting should be consigned to the scrap heap either, though. Like most diets, it’s our belief that if you’re considering intermittent fasting, you should discuss it with your doctor or dietician and come up with a plan. For example, we think that intermittent fasting could be used effectively with another diet (like the Mediterranean diet or the DASH diet). You could try following those dieting rules, but use intermittent fasting to curb snacking around your meals. (In this example, you’d be using time-restrictive fasting.) But, this should only be done with the help of a health care professional so that you know your diet is healthy for you and your specific circumstances.

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Intermittent fasting isn’t the magic bullet for dieting and weight loss that some may view it to be, and we’ve written many times that this option simply doesn’t exist. The best way to achieve weight loss is by living a healthy lifestyle that includes a balanced diet that’s simple to stick with. Dieting is different for everyone, which is why working with your doctor may be helpful. That established, we shouldn’t discount intermittent fasting yet. With it’s promising signs and probable weight loss results, it can be a useful tool while you look for the healthy lifestyle that works for you and may even become an integral part on your health journey.

Further Reading

Johns Hopkins Medicine — Intermittent Fasting: What is it, and how does it work?