The perfect diet is kind of like a unicorn--a nice-sounding, mythical creature that lots of people claim to have seen but doesn't actually exist. However, it turns out that there may actually be a perfect diet (could unicorns be far behind?), but there's a catch: This diet doesn't include any food at all, or at least for long stretches of time.
It's called intermittent fasting. The science behind it is still a little, well, thin (most of the existing research has been done on animals), but the benefits that have been discovered thus far are nothing short of amazing. Let me give you a few examples. Intermittent fasting (we'll talk about what, exactly, that means below) may:
- Decrease blood insulin levels, which accelerates fat burning
- Increase production of human growth hormone, which also accelerates fat burning and muscle building
- Help you reduce the number of calories you eat
- Increase your metabolic rate, meaning you'll burn more calories
- Cause less muscle loss than traditional diets that reduce calories on a daily basis
- Make your body resist oxidative stress, which is a factor in aging and a number of chronic diseases
- Reduce inflammation, which is a factor in many diseases and conditions
- Reduce many of the risk factors for cardiovascular disease, including high blood pressure and high cholesterol; it may also help prevent brain damage caused by a stroke
- Prevent cancer and reduce some of the nasty side effects of chemotherapy
- Increase production of brain-derived neurotrophic factor, which helps keep brain neurons from dying
- Prevent neurodegenerative diseases such as Alzheimer's and Parkinson's
Pretty impressive, don't you think?
Okay, So What Is Intermittent Fasting?
It's pretty much what it sounds like: you fast for short periods and then go back to your regular diet. There are a variety of approaches. Some proponents suggest fasting 16 hours every day (for men; 14 for women), half of which can happen overnight so you won't notice it as much. Others suggest fasting a full 24 hours once or twice per week (no food at all, but water and other calorie-free drinks are okay). Still others say to fast 20 hours per day and do all of your eating during the remaining four hours. Unfortunately, these and other similar approaches will be really challenging for most people.
If It Looks Like Fasting Does That Count?
Then there's the Fast-Mimicking Diet (FMD) advocated by Valter Longo, a researcher at the University of Southern California. Longo and an international group of colleagues did studies on mice and found that putting them on a very-low-calorie diet just four or five days per month boosted their immune system, reduced inflammatory diseases and the incidence of certain cancers, slowed bone density loss, and improved cognitive abilities in older mice. He also did several human trials, putting the volunteer subjects on a highly restricted diet for only five days per month for three months. At the end of the study, the subjects had reduced risk factors relating to aging, cancer, diabetes, and cardiovascular disease--with no negative side effects.
The diet Longo used was meant to produce the same effects in the body as fasting while still allowing for some nutrition. If you were to try this (which you shouldn't do without first checking with your healthcare provider), you'd eat whatever you normally do for 25 days. Then, the actual diet starts. On day one, you eat 1,090 calories, broken down into 23 percent carbs, 56 percent healthy fats, and 10 percent protein. For the next four days, you cut back to 725 calories: 47 percent carbs, 44 percent healthy fats, and 9 percent protein. That's 34 to 54 percent of a normal person's daily caloric intake. Repeat twice more. Do the same three-month cycle a few times per year.
If you've ever tried intermittent fasting or you decide to give FMD a whirl, let us know how you did and what results you saw.