Intermittent Fasting

Written by: Elsie Velazquez cert. personal trainer with Prescription Fitness (Cleveland, Ohio)

Intermittent fasting has become a popular health and fitness trend recently.  It is mostly done by those trying to lose weight, improve their health and/or simplify their lifestyle.  There are many studies that show that it can have a positive effect on your body and brain – essentially, can help you live longer.

Intermittent fasting is an eating pattern cycling between periods of fasting and periods of eating.  For the most part, it is not about what you eat but rather when you eat.  Therefore, it is different than most diets in that it is more focused on the eating pattern rather than the eating itself.

Realistically, fasting has been done throughout evolution. Sometimes it was done because food was not available and sometimes it was done as a part of major religions.  When you think about the fact that our ancestors didn’t have the convenience of supermarkets, refrigerators, and at times could not find food to eat, our bodies are actually able to function without food for extended periods of time.   Fasting from time to time is more “natural” than constantly eating.

These are the most popular methods of intermittent fasting:

  • The 16/8 Method:  This method involves skipping breakfast and restricting your daily eating period to 8 hours, for example from 1 pm to 9 pm. Then you “fast” for 16 hours in between.
  • Eat-Stop-Eat: This method involves fasting for 24 hours, once or twice a week, for example by not eating from dinner one day until dinner the next day.
  • The 5:2 Diet:  This method is done on two non-consecutive days of the week.  On those two days, you only eat 500-600 calories. Eat normally the other 5 days.

When you fast, several things happen in your body.  Here are some changes that occur in your body when you fast:

  • Human Growth Hormone (HGH): Your levels of growth hormone increase significantly. A few benefits of this increase is fat loss and muscle gain.
  • Insulin: Insulin sensitivity improves and levels of insulin drop dramatically. Lower insulin levels make stored body fat more accessible.
  • Cellular repair: When fasted, your cells initiate cellular repair processes.
  • Gene expression: There are changes in the function of genes – increased protection against disease

Even though the above listed benefits are a good reason to give intermittent fasting a try, weight loss seems to be the most common reason that people try intermittent fasting.

By making you eat fewer meals, intermittent fasting can lead to an automatic reduction in caloric intake.  In addition, intermittent fasting changes hormone levels to facilitate weight loss.  Intermittent fasting increases your body’s release of norepinephrine which is a fat burning hormone.  Because of all of these hormone changes, fasting can actually increase your metabolic rate.

Intermittent fasting helps you lose weight by helping you to eat less calories but burn more creating the calorie deficit we all know is necessary for weight loss. An added benefit to intermittent fasting is that your risk of losing less muscle is much lower than with standard methods of calorie reductions (i.e. dieting).

What you should keep in mind, however, is that the main reason this works for weight loss, is that it helps you eat fewer calories overall. If you binge eat during the eating periods, then you may not lose any weight at all.  In fact, it could be counter-productive.

Please keep in mind that intermittent fasting is not for everyone.  You should consult with your doctor before starting.  It is particularly important if you are diabetic, have low blood pressure, take medications, are trying to conceive, are pregnant or breastfeeding.  As long as you are in good health and listen to your body, intermittent fasting could be a good change-up for you.

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