In recent years, few subjects have stoked as much debate in the fitness community as intermittent fasting (or IF, as it is often abbreviated).
While some people swear by the benefits, others fiercely denounce the practice as yet another fad.
What is Intermittent Fasting?
“Rather than a diet, intermittent fasting is a pattern of eating”, explains Robin Young, a fitness expert atFitness Savvy. “While typical diets require you to change what foods you eat, IF simply changes the timing of meals.”
Essentially, you’ll spend periods of time not eating at all (fasting), followed by an “eating window.”
There are three main variations to meal timing:
- Alternate day fasting: As an example, you’ll eat all day Monday, and start your fast after your evening meal, at around 8 pm. Tuesday you’ll fast all day, and then begin eating at 8 pm. Then the cycle continues. As the name suggests, you will alternate; eat one day, fast the next.
- Weekly/24-hour fast: For one day per week, you’ll fast for 24 hours. For instance, your last meal might be breakfast on Sunday. You’ll then eat nothing until Monday, breaking the fast at noon.
- Daily intermittent fasting. This form is often referred to as the Leangains method. You’ll fast every day, with a four to eight-hour period for eating. For example, you could eat from noon until 8 pm every day. This gives you 16 hours of fasting, with an 8-hour eating window.
Benefits of Intermittent Fasting:
- Improved Insulin Sensitivity. Various studies have linked intermittent fasting to improved insulin sensitivity & increased growth hormone, for example, both of which are especially great if you are looking to add or maintain muscle mass.
- Eat larger meals. If you’re someone who tends to overeat with the “little and often” approach, this could be the perfect solution. The fact that you are eating less regularly means that you can increase your portion sizes.
- Live longer. More and more studies are also showing that restricting calories can extend lifespan. So, if you’re planning on outliving your own grandchildren, this is certainly good news!
The Downside to Intermittent Fasting:
- You might feel “Hangry” For the first week or so, until your body adjusts, you are likely to feel hungrier. This might cause you to become more agitated and tired. This could be down to higher cortisol levels (that’s the stress hormone), which studies suggest increase when in the fasted state. In the short-term, this doesn’t appear to be an issue, however, long-term studies in humans are yet to be conducted. If you’re experiencing higher levels of anxiety and stress, feeling tired, having headaches or gaining weight, stop fasting and see a doctor.
- Intermittent Fasting Appears Less Beneficial For Women. Intermittent fasting might not be as favourable for females. Many online articles concentrate on the health benefits for men, while neglecting to mention the hormonal impact on women. Studies have shown detrimental insulin response in women, poorer muscle adaptations and higher levels of stress.
- Lack of research in humans. Most of the research cited by those promoting intermittent fasting was conducted on mice and rats. While the results are promising, further research needs to take place with human subjects.
The intermittent fasting naysayers argue that the scientific evidence is mixed, and that the negatives outweigh the benefits. Often, they will highlight how others have achieved similar, or better results, by eating regular meals.
Indeed, the evidence is mixed, yet one fundamental fact remains: It is extraordinarily difficult to eat too many calories in a short period of time, consistently. With this in mind, those who overeat with the little and often approach, might find IF to be the perfect short-term solution.
Still not sure if intermittent fasting is for you? Concerned it might affect your fertility or reproductive hormones? If this sounds like you, consult with your doctor, try it out, and if it works – carry on with it. If you’re happier, seeing results, and feel great, don’t let anyone tell you you’re wrong and to change it.
Have you tried it for a few weeks and feel terrible? If this is the case, then maybe IF isn’t for you.
Image Credits: Intermittent Fasting from everydayplus /Shutterstock