Creating An Optimized IF Diet

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Creating An Optimized IF Diet

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Intermittent Fasting

The Intermittent Fasting (IF) diet is an eating pattern involving periods of eating and fasting. It has become very popular in recent years with athletes, celebrities and everyday people adopting the practice. Generally, this diet doesn’t specify what you should eat but instead deals with when.  In this article, we will look at how to best optimize IF for the best results in energy, fat loss and muscle gain. The period for the fast varies, but studies indicate that it usually lasts between 12 and 40 hours.  Depending on how strict the fast is, you can take calorie-free beverages and water during the fasting period, but solid foods and drinks that contain calories are not permitted.

This article discusses various strategies for intermittent fasting, the pros and cons of this eating pattern, and makes recommendations based on scientific evidence.

Is It The Miracle Diet?

It must be pointed out that there is often a big misunderstanding that the IF diet is the miracle diet. It is not! Calories still matter so do macros.  If you are trying to lose weight using the IF method you still need to be in a calorie deficit to do so, no different than not fasting and eating less.  To further optimize your fat loss it is also highly recommended to consume more protein also as protein helps keep you more full and has a slight thermogenetic effect on body fat.

Different Strategies for Intermittent Fasting (IF)

In its position paper on different forms of diets, the International Society for Sports Nutrition mentioned three different methods or subclasses of intermittent fasting. They are alternate-day fasting (ADF), whole-day fasting (WDF), and time-restricted feeding (TRF).

Whole-Day Fasting (WDF)

Whole-day fasting involves picking a day or two where you fast in a week. Generally, on fasting days, there is a limit to the energy intake, with individuals usually expected to take in no more than 500 calories.  Like the other forms of intermittent fasting, WDF has been shown by multiple studies to cause weight loss and other health benefits. It is also referred to as the 5:2 diet because there is a 5-day eating window and a 2-day fasting window.

Intermittent fasting

Alternate-Day Fasting (ADF)

This is the most common kind of intermittent fasting, and it is the kind of intermittent fasting that has been greatly studied. ADF involves 24 hours of fasting followed by a 24-hour of eating. Like WDF, alternate-day fasting allows individuals to have some calorie intake on fasting days,  about 20-25% of what they would ordinarily require. ADF has also been shown to facilitate weight loss alongside other health benefits like improving brain power

Time-Restricted Feeding (TRF)

This involves a fasting period of about 16-20 hours followed by an eating period of 4-8 hours daily. TRF is well exemplified during the Ramadan fast for Muslims, which involves fasting from sunrise to sunset for about a month. It is not surprising that one of the significant consequences of TRF is weight loss, and studies have shown that TRF affects both fat mass and lean mass

Different studies have been conducted or reported by the ISSN on these intermittent fasting methods. These studies have also measured the effects of these intermittent fasting methods vis-a-vis other calorie regulation diets and methods.

Intermittent Fasting Facts

Here is a link to get complete details on these studies, and other information on other forms of diet plans:

The Pros and Cons of Intermittent Fasting (IF)


Pros of IF

Research has uncovered multiple benefits of intermittent fasting, and we discuss some of them below:

1. It may contribute to weight loss and improve metabolic health.

One of the fundamental reasons why people try intermittent fasting is for weight loss or to improve how the body performs metabolic functions. Research shows that intermittent fasting reduces the calories individuals need to maintain a particular weight, leading to weight loss. Furthermore, research has also uncovered that IF doesn’t necessarily have more significant effects than other calorie-reducing plans that do not require fasting.

In one randomized trial for 116 participants published by the National Centre for Biotechnology Information, researchers concluded that time-restricted feeding led to weight loss.

Intermittent Fasting

Read full details of the trial here:

Another trial published by the NCBI, which tested IF for 50 weeks, also reported weight loss, even though no significant weight loss was obtained from a daily calorie restriction. This particular study made use of the 5:2 method of intermittent fasting.

Read full details of the trial here:

Beyond the effect on the calories in the body, intermittent fasting may also cause weight loss by regulating the body’s hormones and stimulating the feeling of fullness while limiting the feeling of hunger. A study published by the NCBI on eleven overweight adults supports this.

Intermittent Fasting facts

Read full details of the study here:

2. IF has been linked with specific health benefits.

Intermittent fasting has been linked to certain exciting health benefits, such as lowering blood pressure. A study with over 1000 participants published by the NCBI showed that prolonged fasting helped reduce blood pressure and helped to alleviate other emotional and physical health conditions.

Intermittent Fasting

Read further details here:

Another significant health benefit that has been linked to intermittent fasting is the repair of damaged cells. A review published by the NCBI stated that food deprivation or fasting led to autophagy in a wide variety of tissues or organs. The study defined autophagy thus: “Autophagy functions to recycle building blocks and energy for cellular renovation and homeostasis, allowing cells to adapt to stress.”

Intermittent Fasting facts

Read further details here:

Other health benefits that have been linked with intermittent fasting include the protection of brain health and the improvement of blood sugar levels.

A study that shows how intermittent fasting protects brain health was published by the NCBI here:

3. IF usually fits right into your diet.

Since IF does not stipulate anything for you to eat, you can easily adapt it to your current diet without the need to get extra food. Your current diet may work just fine, and you could simply complement it by adding any intermittent fasting methods.

Cons of IF

1. You will have to deal with some hunger and frustration.

Fasting for 24 hours or even 16 hours may mean that you will go to bed hungry on many days or deal with the day’s activities while feeling hungry. This may not be convenient at first, and your body may not agree with this method. When you consider that you can get similar results (regarding weight loss) without fasting, it even looks less appealing.

2. IF may affect your social life.

Often, bonding and even business deals happen over meals, and it will be increasingly socially awkward to be unable to eat at every other engagement or meeting. Furthermore, fasting affects your energy levels, and you may be unable to move as much as you want on “fasting days.” This could affect the amount of commitment you are able to give to social activities.

3. Negative effects on mood

Scientific research has shown that people are more irritable and anxious when they have to fast or reduce calories. A study by the NCBI on the effects of fasting on healthy women supports this.

Fasting facts

Read full details here:

Recommendations for Intermittent Fasting Diet

Intermittent fasting is largely safe, with main side effects being hunger and feelings of weakness. However, it becomes easier to manage and live with as you grow used to it. Here are some general recommendations that may help as you consider IF:

  • You can take water, coffee, and other calorie-free beverages on fasting days and hours.
  • If you have a medical condition, you should consult your doctor before trying intermittent fasting. Some conditions that may particularly require that you avoid IF are diabetes and low blood pressure.
  • Take in nutrient-dense food during your eating periods especially protein.

Intermittent Fasting facts


IF is a unique way to diet, and the different methods allow individuals to pick what works best for them. However, it is essential to note that while it has positive health effects, if an individual has pre-existing health conditions, it could worsen them. 

The Body Transformation Nutrition Coach (BTNC®)

To learn more about diets that work to maximize your own body transformation and that of your clients, check out the BTNC® certificate course by the GPNi®.  In the course, we break down all the modern diets from the viewpoint of the latest science. This helps you give individual  advice and suggestions to your clients.

The BTNC® course is great for beginner to moderate individuals, that want to understand the science and fundamentals of sports nutrition for fat loss and lean muscle gain.  Get ready to transform your body and your clients with the most up-to-date sports nutrition strategies today!

Learn more about the BTNC® course here: Available online and on-demand July 2022.


To know more about intermittent fasting, get learning resources such as those listed below, and register today to be a Sports Nutrition Specialist (SNS®) on the GPNi® platform.

You also learn about the GPNi®’s patented “traffic light system.”

  • Green – Good & Solid Research
  • Orange – Some Limited Research but Not Considered Harmful
  • Red – No Solid Research and Maybe Some Health Concerns

Gpni patent traffic light system

This enables you to learn what to safely recommend to your clients, athletes, and yourself.

You can also choose one of our Continued Education Certificate programs, such as the Endurance & Marathon Nutrition Coach (EMNC®) certificate program.

Send us an email if you have any questions to

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