Learn everything you need to know about intermittent fasting, from how to do it to the science behind this approach.
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Intermittent fasting is an eating approach that involves long periods of fasting followed by short periods of eating or 24 hours of fasting followed by 24 hours of eating.
There are several variations of intermittent fasting, the most popular of which is fasting for 16 hours followed by 8 hours of eating..
The basis of intermittent fasting is based on a few key ideas.
Maximize the time the body spends oxidizing fat.
Minimize global insulin load.
There are several studies carried out examining how these claims are proven, or not, and the results have been quite interesting..
Key Components of Intermittent Fasting
As mentioned above, intermittent fasting is based on prolonged periods of fasting followed by a period of eating.
Intermittent fasting does not normally have defined calorie amounts, macronutrient proportions, nor does it have a list of good and bad foods to eat..
In other words, when it comes to choosing food, it is not very restrictive.
Timing and frequency of meals
Unlike many other plans or diets, intermittent fasting depends almost exclusively on meal timing and frequency..
As we already know, intermittent fasting typically adopts a 16-hour fasting window, followed by an 8-hour eating window..
Most people consume 1-2 very large meals during the eating period, although several small meals can be consumed over this time..
Other fasting approaches such as alternative daytime fasting employ a 24-hour fast followed by a 24-hour full feed..
Restrictions and limitations
Apart from restrictions and time limitations, there are no food restrictions. This is often interpreted as a free-for-all during the feeding period.
However, in practice, people who get the best results using intermittent fasting typically apply another eating structure (such as IIFYM or flexible dieting) to give them some structure to their food intake during the eating period..
Are there different phases?
Intermittent fasting does not include any phases in its eating protocol, although some people go through fasting cycles in which they spend long periods of adhering to fasting protocols and then periods of normal eating..
Who is this approach best suited to?
Intermittent fasting is best suited for people who have busy schedules and prefer to eat 1-2 meals a day rather than spreading them out throughout the day..
Fasting can also be excellent for people who are learning new and better eating habits.
Intermittent fasting is also a great way to help people control calories, as often reducing the time you eat during the day can reduce calories overall..
How easy is it to follow?
Intermittent fasting is easy to follow because it doesn't limit or restrict food, it allows you to eat without tracking calories, and it doesn't put an obstacle in your social life (not being able to go out to dinner and order something from the menu).
It can also make life much easier as there is less time spent cooking, eating and cleaning.
It can be difficult for some people who enjoy the process of cooking and eating, as well as having initial difficulties controlling hunger due to long periods without eating..
Scientific Studies and Data Interpretation
There are several studies that delve into the benefits of intermittent fasting as a tool to promote fat loss..
The ideal of fasting to promote health benefits has existed since ancient civilization.
Nowadays, many of the speculations about the general health benefits of fasting are still a reason for debate, and the big question is whether their origin lies mainly in the calorie deficit or in the fasting itself..
Below, we will outline some of the studies that have been conducted that present these benefits on an unbiased platform..
Benefits in fat loss
One of the biggest claims of intermittent fasting is that it's an excellent tool for fat loss..
There have been several studies that have examined the role of meal frequency in fat loss, including things like alternate daily fasting and even the intermittent fasting protocol..
For a long time, these studies were eliminated by social media and fitness forums, as they were not true studies on the specific intermittent fasting protocol; however, a study was recently done that followed the traditional 16/8 fasting protocol, as prescribed by traditional intermittent fasting protocols (1).
In this study, the group that followed the intermittent fasting protocol lost about 1.5kg more fat than the normal diet group; however, this also occurred simultaneously with a lower caloric intake than the normal diet group, so it is likely that the greater fat loss was due to a lower caloric intake..
However, the most curious data is not the amount of fat lost.
One of the most interesting notes about this study, as mentioned by Greg Nuckols is that, “Testosterone and IGF-1 levels decreased, levels of several pro-inflammatory cytokines decreased, cortisol levels increased, insulin and glucose levels increased. in the blood decreased, triglyceride levels decreased, T3 levels decreased and RER decreased slightly.
This is all expected data on a hypocaloric diet, however, although the intermittent fasting group was in a calorie deficit, this was very low (less than 10% below the maintenance value), which was probably not a sufficient deficit to justify these effects..
Overall, does this study make it seem like intermittent fasting tricks your body into thinking you're dieting, even if you're at (or at least close to) caloric maintenance, in a way generally consistent with improved health and longevity? (two).
Benefits in increasing muscle mass
When looking at the fasting literature, it appears that intermittent fasting does not appear to provide any additional muscle-building benefits when calories are kept the same..
That said, periods of fasting can improve the quality of muscle tissue by increasing its cellular cleansing processes (e.g., autophagy and heat shock protein response) (3,4,5).
However, this research is currently preliminary and is mostly speculation at this time.
General Health Benefits
Of all the areas of research into fasting, the effects on general health and longevity are perhaps the most interesting.
Several studies in animal models have shown that periods of fasting increase life expectancy and improve several metabolic parameters as these animals age (6,7).
Perhaps the best-known phenomenon of fasting is the increase in autophagy, a cellular cleansing process.
There is some evidence from animal studies that also suggests that fasting may increase longevity; however, the data in humans is short-term, and long-term evidence is not yet concrete, so much of this is still speculation (8)..
Intermittent fasting offers a flexible eating approach to dieting and may have some unique metabolic benefits for health and longevity..
From a fat loss perspective, intermittent fasting can be an excellent tool, mainly due to controlling calorie intake..
Intermittent fasting can be used in its widely known format of a 16-hour fast followed by an 8-hour eating period; alternative daily fasting approximates a 24-hour fast followed by a 24-hour feed.
Intermittent fasting is easy to follow because it does not limit or restrict food, it allows you to eat without following tight calories.
Have you tried this dietary approach? Leave your opinion in the comments!
References 1) Effects of eight weeks of time-restricted feeding (16/8) on basal metabolism, maximal strength, body composition, inflammation, and cardiovascular risk factors in resistance-trained males. two) The ?Leangains? Intermittent Fasting Study Is Finally Here. 3) AMPK Activation of Muscle Autophagy Prevents Fasting-Induced Hypoglycemia and Myopathy During Aging. 4) Autophagy is required to maintain muscle mass. 5) Long-Term Calorie Restriction Enhances Cellular Quality-Control Processes in Human Skeletal Muscle. 6) Apparent Prolongation of the Life Span of Rats by Intermittent Fasting. 7) Fasting: Molecular Mechanisms and Clinical Applications. 8) Effect of 6-Month Calorie Restriction on Biomarkers of Longevity, Metabolic Adaptation, and Oxidative Stress in Overweight Individuals A Randomized Controlled Trial.
Adapted from muscleandstrength.com article