Odds are, you’ve heard about intermittent fasting. Not just a part of religious rituals anymore, fasting is taking the dieting and fitness world by storm, and lots of scholarly ink is being spilled to figure out how effective it really is.
Not only are intermittent fasting proponents skipping breakfast, some are even skipping full days of eating altogether. But they aren’t crazy.
People seeking to lose weight and keep it off are reporting promising results thanks to intermittent fasting and it’s drawing the attention of bodybuilders and athletes everywhere.
As with all new health crazes, intermittent fasting is being dismissed by some as a passing fad, despite the ample evidence that it may actually be extremely beneficial. So, I’ve collected a list of nine common lies and misconceptions you may run into when learning about this new technique.
- Lie #1: You can lose weight without a calorie deficit
- Lie #2: You have to go entire days without food
- Lie #3: It's better to eat throughout the day at short intervals
- Lie #4: Intermittent fasting causes serious health problems
- Lie #5: Intermittent fasting leads to nutrient deficiencies
- Lie #6: Intermittent fasting causes you to lose muscle mass
- Lie #7: Fasting makes you move less
- Lie #8: Intermittent fasting leads to eating disorders
- Lie #9: Intermittent fasting leads to fertility issues in women
Table of Contents
Fitness and weight loss gurus have been all over intermittent fasting for the past few years, proclaiming it as the weight loss technique of the future. One of the main claims they make is that you won’t have to worry about counting calories anymore.
They say about feed-days: eat as much as you like, whatever you like, and you’ll still lose weight!
This is completely false and potentially dangerous for people who want to attempt the intermittent fasting diet. The body requires a negative energy balance to lose weight. You have to put less energy into your body than you burn to have weight loss over time, period.
There’s no magical way to get around the body’s energy balance. In order to lose weight successfully, especially if you’re seeking to build muscle mass, you need to control your energy intake. If you’re considering intermittent fasting because you think it will allow you to eat all the junk food you want, you’re probably not ready for it.
To a lot of people, myself included, the idea of spending an entire day without eating anything sounds a little daunting. When people hear the word ‘fasting’, they associate it with complete starvation. But that’s not necessarily the case.
Dr. Krista Varady, author of The Every-Other-Day Diet during her post-doc research at the University of California Berkeley, found that mice who consumed 25 percent of their daily calories one day, did not end up consuming 175 percent the next day. Because they weren’t fully compensating for the lack of food the day before, they began to lose weight.
When this was put into practice in human beings, on average they only consumed around 115 percent of their daily caloric allowance on the days they were allowed to eat as much as they wanted.
Assuming your average diet is around 2000 calories, a fast day might be cut down to around 500 calories. If you want to push your body’s limits, you could cut down further, but it’s not the recommended course of action by proponents of intermittent fasting.
There’s no evidence that snacking is always better for fat loss. There are some benefits to consuming protein throughout the day, but the idea that you have to stoke your metabolism, is fiction.
One of the major problems dieters find is just how difficult it is to comply with the strict regulations of their diets. Consistently low-calorie diets (on a daily basis, with few if any days of indulgence) are notoriously hard to abide by. Faltering even slightly can seriously affect the balance of your metabolism, harming your body and your efforts to lose weight.
In a recent study by the Brazilian Medical Association, intermittent fasting has been demonstrated to be easier to comply with than other weight loss regimens, providing a consistent negative energy balance over time.
What seems to be the main effect of intermittent fasting is how it helps the body to more properly respond to insulin, the hormone that regulates blood sugar. This study showed for the first time that while on an intermittent fasting diet, the body was more capable of responding to insulin.
People who suffer from obesity typically have a harder time regulating insulin, a condition linked to diabetes and heart failure. However, people whose cells respond well to insulin (and are probably not suffering from obesity) need less of the hormone and typically live longer.
If intermittent fasting helps you eat less and lose weight, it will probably help you avoid other health complications. However, there’s still no evidence that intermittent fasting, by itself, increases or decreases your risk of disease.
The main thrust of intermittent fasting is in teaching your body to eat during certain intervals rather than throughout the day. Fasting for a single day, even if you ate nothing whatsoever, simply cannot lead to a nutrient deficiency. Your body isn’t that fragile.
You’re going to eat again the very next day, or in some cases within a few hours. If you’re maintaining a healthy and balanced diet when you do eat, you’ll be fine.
Still feel worried? Try taking a regular multivitamin. Limit your fasting days to twice a week instead of every other day. Intermittent fasting isn’t some risky method of cleansing your system; it’s about teaching your body to control urges and better self-regulate.
The reason why muscle mass is lost during extreme dieting is because past a certain point, your body has to break down muscle to meet your energy needs. You simply don’t have enough carbohydrates or calories from fat to burn, so your body increases the breakdown of muscle tissue.
In the catabolic state (where muscle tissue is cannibalized) the body goes through a process called de novo gluconeogenesis, or DNG, wherein amino acids in the bloodstream are broken down into glucose. When the body can no longer find these amino acids (when it’s starving after particularly prolonged fasting) it finds it where it is most abundant: the muscle tissue.
This is nothing to worry about with intermittent fasting. The body doesn’t need a constant supply of amino acids if it wants to maintain muscle tissue.
If your last meal before beginning your fast was large and well-balanced, you shouldn’t have to worry about these complications.
That said, going long periods of time between meals also means you won’t be stimulating protein synthesis during that time. So, while you won’t be causing muscle loss, you won’t be causing much muscle gain, either.
A study by the American Journal of Clinical Nutrition found that alternate-day fasting (ADF), a 400-600 calorie fast-day followed by a regular day of calorie consumption, demonstrated zero loss of muscle mass after 8 weeks. The average weight loss for the participants was 12 pounds, all from fat stores, without the subjects making any effort to maintain muscle mass or a high protein intake.
Remember Dr. Varady from earlier?
Varady, in an experiment to measure and compare performances, had several groups of people wear accelerometers. Some were on the intermittent diet, others were on consistent daily calorie counting diets, while others were on no diet at all. She reported no statistically significant difference in the daily activity of these groups.
She did admit, however, that during the first 10 days of the intermittent fasting diet, people were less likely to go out and exercise, but afterward they resumed exercising at the same levels as they did prior to intermittent fasting.
Dr. Varady told The Atlantic: “But the really interesting thing about that study is that it was best to exercise in the morning on those fasting days”.
The dieters were able to lose more weight by exercising in the morning before their fast-day (heavily-restricted calorie) meal than were those dieters who exercised after the meal. Varady blames this on the impulse to cheat and eat another small meal or snack post-workout.
If you fear you may be undisciplined in your dieting and workout regimen, you probably aren’t right for the intermittent fasting diet. Again, this is a technique employed by bodybuilders and athletes; it’s not usually for your average guy with a dad body.
There are some examples of people who claim that intermittent fasting caused them to develop an eating disorder. More likely, the kind of person attracted to a new dietary strategy is more susceptible to disordered eating habits.
A lot of this seems to be the result of people who take the days where they are allowed to eat as they please as opportunities to gorge themselves on cake and pizza, eating until they feel completely stuffed, overdoing it.
This is not okay. Some intermittent fasting plans say those who follow it can eat as they wish, but they should still be responsible. If you are a person prone to psychological or emotional disorders, or especially if you have a prior history of eating disorders, the intermittent fasting diet is not for you.
But, if you follow the protocols of the diet and maintain a proper negative energy balance for weight loss, being disciplined and careful about what you eat, you can easily avoid these complications.
Some websites out there claim that intermittent fasting should not be attempted by women as it could potentially lead to fertility issues. While it is true that women who engage in extreme calorie intake changes and weight training/ intensive exercise do report menstrual complications, these have yet to be linked to intermittent fasting.
The International Journal of Fertility and Sterility performed a study on the effects of intermittent fasting on ovulation and progesterone levels in 24 women with normal menstrual cycles and found no change when fasting compared to when they weren’t fasting.
In another study, it was found that intermittent fasting in young, obese women had the same benefit as a daily calorie restriction diet for “improving weight loss, insulin sensitivity and other health biomarkers”.
If you decide to try intermittent fasting and find yourself experiencing such issues, you should speak to your doctor about how to transition back into a regular diet.
The most important aspect of intermittent fasting, and what you can take away from all of the research is this: watch what you eat. Know how many calories are coming from proteins, carbs, and fats. Stick to foods that you know are nutritious.
Intermittent fasting is one of those rare diets that can actually demonstrate real results. It’s not generally optimal for muscle growth. But, if it sounds like it might meet your diet and fitness needs (and if you feel like you’re up to the challenge), it may be a good idea for you to try it out.