What the Science Says About Intermittent Fasting
Is it a good idea to “starve” yourself just a little bit each day, or a couple of days a week?
Mounting evidence indicates that yes, intermittent fasting (IF) could have a very beneficial impact on your health and longevity.
I believe it’s one of the most powerful interventions out there if you’re struggling with your weight and related health issues. One of the primary reasons for this is because it helps shift your body from burning sugar/carbs to burning fat as its primary fuel.
Intermittent fasting is not about binge eating followed by starvation, or any other extreme form of dieting. Rather what we’re talking about here involves timing your meals to allow for regular periods of fasting.
I prefer daily intermittent fasting, but you could also fast a couple of days a week if you prefer, or every other day. There are many different variations.
To be effective, in the case of daily intermittent fasting, the length of your fast must be at least 16 hours. This means eating only between the hours of 11am until 7pm, as an example. Essentially, this equates to simply skipping breakfast, and making lunch your first meal of the day instead.
You can restrict it even further — down to six, four, or even two hours if you want, but you can still reap many of these rewards by limiting your eating to an eight-hour window each day.
This is because it takes about six to eight hours for your body to metabolize your glycogen stores; after that you start to shift to burning fat. However, if you are replenishing your glycogen by eating every eight hours (or sooner), you make it far more difficult for your body to use your fat stores as fuel.
Intermittent Fasting — More a Lifestyle Than a Diet
I have been experimenting with different types of scheduled eating for the past two years and currently restrict my eating to a 6- to 7-hour window each day. While you’re not required to restrict the amount of food you eat when on this type of daily scheduled eating plan, I would caution against versions of intermittent fasting that gives you free reign to eat all the junk food you want when not fasting, as this seems awfully counterproductive.
Also, according to research published in 2012, intermittent fasting with compensatory overeating did not improve survival rates nor delay prostate tumor growth in mice. Essentially, by gorging on non-fasting days, the health benefits of fasting can easily be lost. If so, then what’s the point?
I view intermittent fasting as a lifestyle, not a diet, and that includes making healthy food choices whenever you do eat. Also, proper nutrition becomes even more important when fasting, so you really want to address your food choicesbefore you try fasting.
This includes minimizing carbs and replacing them with healthful fats, like coconut oil, olive oil, olives, butter, eggs, avocados, and nuts. It typically takes several weeks to shift to fat burning mode, but once you do, your cravings for unhealthy foods and carbs will automatically disappear. This is because you’re now actually able to burn your stored fat and don’t have to rely on new fast-burning carbs for fuel. Unfortunately, despite mounting evidence, many health practitioners are still reluctant to prescribe fasting to their patients. According to Brad Pilon, author of Eat Stop Eat
“Health care practitioners across the board are so afraid to recommend eating less because of the stigma involved in that recommendation, but we are more than happy to recommend that someone start going to the gym. If all I said was you need to get to the gym and start eating healthier, no one would have a problem with it. When the message is not only should you eat less, you could probably go without eating for 24 hours once or twice a week, suddenly it’s heresy.”
The Health Benefits of Intermittent Fasting
Aside from removing your cravings for sugar and snack foods and turning you into an efficient fat-burning machine, thereby making it far easier to maintain a healthy body weight, modern science has confirmed there are many other good reasons to fast intermittently. For example, research presented at the 2011 annual scientific sessions of the American College of Cardiology in New Orleans showed that fasting triggered a 1,300 percent rise of human growth hormone (HGH) in women, and an astounding 2,000 percent in men.
HGH, human growth hormone, commonly referred to as "the fitness hormone," plays an important role in maintaining health, fitness and longevity, including promotion of muscle growth, and boosting fat loss by revving up your metabolism. The fact that it helps build muscle while simultaneously promoting fat loss explains why HGH helps you lose weight without sacrificing muscle mass, and why even athletes can benefit from the practice (as long as they don't overtrain and are careful about their nutrition). The only other thing that can compete in terms of dramatically boosting HGH levels is high-intensity interval training.
Other health benefits of intermittent fasting include:
Normalizing your insulin and leptin sensitivity, which is key for optimal health
Improving biomarkers of disease
Normalizing ghrelin levels, also known as "the hunger hormone"
Reducing inflammation and lessening free radical damage
Lowering triglyceride levels
Preserving memory functioning and learning