On a recent episode of illustrious podcast The Joe Rogan Experience, the renowned host sat down with endurance athlete and longevity specialist Dr. Peter Attia. Trained as a cancer surgeon, Dr. Attia’s current practice focuses on engineering a longer and higher quality of life for his patients.
Well within character for JRE, the pair soon found themselves discussing diet, nutrition, and the countless benefits of intermittent fasting. Having been intermittently fasting for five years, Dr. Attia follows what many would likely consider an extreme version of the health practice: He only eats within a two-hour window every 24 hours. Alternatively, if somehow constrained by circumstance, he will employ a “short” fast of 16 hours.
Dr. Attia would go on to explain the biological theory behind fasting:
“If our ancestors couldn’t function when they were hungry, we wouldn’t be here. So it’s not just that a short-term adaptation to starvation is necessary—it’s probably beneficial. In other words, during these short periods of deprivation of food, we get just a little bit more epinephrine and norepinephrine. We get a little bit sharper, a little bit better.”
Based on personal experience, Dr. Attia laid out several practical considerations that make a solid case for giving this eating pattern a try.
#1. Fat Burn/Weight Loss
Dr. Attia referenced one study in which mice fasted for 16 hours followed by eight hours of eating whatever and however much they wanted. Despite the unrestricted nature of their feeding in that eight-hour window, the mice would not gain weight. According to Dr. Attia, the theory behind these results is that the 16-hour fast allowed the mice to ramp up liver enzymes responsible for metabolizing fat.
Although we should use caution in extrapolating this study to humans (a 16-hour fast is much longer for a mouse than an adult human being), it stands to reason that we could expect a similar benefit, albeit on a smaller scale.
#2. Less Restricted Food Options
Much like the mice in the study, Dr. Attia described his voracious appetite during the two-hour feeding window. He can easily devour several thousand calories in a sitting after fasting for 22 hours. Despite consuming an entire day’s worth of food in one meal, he swears by the diet’s contribution to his overall health.
Even more beneficial, though, is the increased freedom with the quality of his food in the feeding window. According to Dr. Attia, his physiological response to food—for example, a change in blood sugar—is much more resilient after a 22-hour fast. This flexibility can make dieting that much easier for the health-conscious eater.
#3. Freedom from Planning Meals
In a similar light, the ability to go hungry for long periods of time alleviates the pressure of constantly remaining in arm’s reach of substantive food—especially for those who “eat clean.” A social life, traveling, and any other activity that limits your access to food can be a heavy drag on those who are particular about their diets.
Depending on the goals of your diet, intermittent fasting can relieve much of that anxiety. Bodybuilders and high-level athletes who require upwards of 6,000 calories daily probably won’t find much utility in a two-hour feeding window. However, the everyday fitness enthusiast who wants the most convenient way to maintain a healthy physique can find tremendous benefit in this eating pattern.
#4. Steadier Energy Levels
Finally, Dr. Attia explained one of the most immediate benefits he picked up from intermittent fasting was bidding farewell to the post-lunch crash. Just about anybody with a regular nine-to-five work schedule has probably been there: You get out of bed groggy and force yourself through the morning in a coffee-fueled auto-pilot, only to have it all backfire when you run out of steam after a big midday meal.
From a scientific standpoint, intermittent fasting keeps your sugar levels in check and doesn’t put your body through the physiological roller-coaster that sometimes accompanies more traditional eating schedules. When you only eat within a few hours each day, your body is always primed to handle an onslaught of calories when that feeding window comes back around.
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