Intermittent fasting (IF) is one of the hottest trends in the health and fitness world right now. There’s huge interest in its benefits, applications, and how it compares to other eating patterns so let’s take a closer look and answer some of the most common questions.
What Is Intermittent Fasting?
Intermittent fasting refers to an eating approach that cycles between periods of eating and fasting. It’s more focused on when you eat rather than what you eat.
During fasting periods, energy intake (or calories) is restricted, which typically results in an overall calorie deficit, the key factor behind any weight loss that occurs.
The main types of intermittent fasting that have been studied include:
-
Whole Day Fasting: One to two 24-hour fasting periods per week
-
Alternate Day Fasting: One fasting day followed by one day of eating
-
Time-Restricted Fasting: Fasting for 16–20 hours each day (this is the most common type and often the easiest to implement)
What Are the Benefits of Intermittent Fasting?
Most people try intermittent fasting for weight loss — and research shows it can be effective. However, the results are comparable to any other calorie-restricted diet.
Weight Loss and Convenience
Fasting naturally limits the time available to eat, which helps many people reduce calorie intake without tracking every meal. This can make it a simpler approach for those who don’t want to count calories.
Insulin Sensitivity and Glucose Control
Current research indicates that intermittent fasting offers similar benefits to other energy-restricted diets for insulin sensitivity and blood sugar control. Findings are mixed, but ongoing studies continue to explore potential long-term effects.
Chronic Disease Prevention
Some emerging research suggests intermittent fasting may help reduce the risk of chronic diseases — though more evidence is needed to confirm this.
Intermittent Fasting and Exercise
Intermittent fasting can suit some active individuals or recreational athletes if it’s carefully planned around training sessions.
Training in a Fasted State
Some studies suggest fasted endurance training may improve the body’s ability to use fat as a fuel source (known as becoming “fat adapted”). While this hasn’t been shown to boost performance directly, it may benefit those training for endurance or ultra-endurance events.
If your goal is weight loss, exercising while fasting may also help create a larger energy deficit. However, there are important considerations:
-
If your performance drops during fasted training, you may not be fuelling effectively.
-
If fasting leads to overeating later in the day, it may undo your calorie deficit.
As with any nutrition approach, balance and planning are key.
Intermittent fasting is one of many possible strategies for weight management and overall health. While it can be effective for some people, it’s not a magic fix — success still comes down to consistency, total energy balance, and how well the approach fits your lifestyle.
If you’re unsure if it’s right for you, you can read more about the practical applications in our related article, Intermittent Fasting: Is It for You?