Diet fads come and go, and, in the long run, don’t actually do much to help people keep off the weight that they may initially lose. So, what can potentially work, aside from exercise and eating healthy, like we talked about a few weeks ago? Do we really need three big meals a day as adults, given we’re not infants, toddlers or teens who are growing and in need of the calories for this intensive process? What about intermittent fasting?


Decades of research have shown that extreme calorie restriction – a reduction of 20% – 40% – dramatically extends the lives of animals, but with one caveat: so long as they get the nutrients they need. You cannot fast for many hours and then eat nutritionally absent foods, like the highly processed ones so typical of the Western diet, as that can lead to malnourishment and the resulting health effects from that, like muscle and bone density losses.


A four-year experiment on fasting tracked hundreds of mice over their lives. Automated feeders allowed some mice to eat as much as they wanted, while greatly reducing calories for others and allowing that group access to food on different time schedules (within a 2-hour period; within a 12-hour period; around the clock; day versus night). Scientists found that restricting calories increased the lifespan of the mice by 10%. But coupling that with limiting food consumption to 2 hours at night (which is peak activity time for mice) extended their lifespan by 35%. For humans, this would be the equivalent of 25 years, on average! To apply this kind of research to humans, though, would take thousands of volunteers who would be willing to adhere to a fasting regime for multiple years. In its place, a 2019 study showed progress, where, from the 2,000 heart patients that were observed, those who fasted routinely were found to still be alive four years after a common procedure called cardiac catheterization, compared with patients who never fasted, did it briefly or stopped many years earlier.


Another study, focused on firefighter performance during fasting, led to unexpected findings. The firefighters didn’t experience sluggishness or mental fogginess, as feared. The fasting group instead showed improvements in cholesterol, blood pressure and glucose levels. The modern Western diet has thrown metabolism out of whack and so fasting helps the body switch from sugar-burning to fat-burning mode. At this point, years of clinical trials on intermittent fasting have concluded that there is enough evidence of health benefits that it is worth a try. But, again, WHAT you eat really matters – healthy food versus highly processed foods. If you’re looking to experiment with this, ease into it slowly. Try 10-hour overnight fasts (if you go to bed at 10 PM, the next time you would eat would be 8 AM), then 12 hours (10 PM – 10 AM). If you’re really ambitious, up this to 14 hours (10 PM – 12 PM lunch). Have you tried fasting?

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photo: by Ulyana Peña