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Forget those “fad diets”—honor your evolutionary roots instead

Vegan. Gluten-free. Carnivore. The list of “trendy” diets is nearly endless these days. And I’m sure you roll your eyes when another “latest and greatest” comes to town.

But tell me, what comes to mind when you hear intermittent fasting (IF)? Are you fearful? Do you think it’s all hype?

After all, the word “fasting” alone can bring fear into a person’s eyes. I see it all the time.

Air travel paints a perfect example of this panic. Passengers board the plane with what seems like a week’s worth of groceries… all for a trip that won’t even last two hours.

But a day without food won’t kill you. And by now, it should be clear that IF isn’t the fad diet some people mistook it for when it first started making waves in the nutritional research community a few years ago.

In fact, it really isn’t a “diet” at all.

Simply put, IF honors your body’s evolutionary roots… and offers countless science-backed health benefits along the way.

Physiologically, when you fast, there are many biological processes taking place that allow your body to start metabolizing the foods you eat more efficiently.

So, let’s take a closer look at these benefits—some of which surprised even me—along with a few tips for adopting IF into your healthy lifestyle…

Melt away body fat

A new analysis recently appeared in the Journal of the International Society of Sports Nutrition. And it focused on a form of IF called time restricted eating (TRE) among athletes.

Researchers separated 16 elite cyclists into two separate groups. One group ate between 7 a.m. and 9 p.m. The other group restricted their eating to an eight-hour window, between 10 a.m. and 6 p.m.

After just four weeks (during which they maintained their normal training schedules), the subjects using TRE lost two percent of their body mass and one percent of their fat mass compared to controls.1

That may not sound like a lot… until you consider the fact that these subjects were exceptionally lean to begin with. So if TRE can deliver results like this to highly trained endurance athletes with minimal body fat, just imagine what it could do for someone with a significant amount of weight to lose!

But that’s not all. These researchers uncovered more benefits than simple weight loss… they also saw positive effects on subjects’ immune system markers.

And since hard training periods can sometimes increase your susceptibility to infection, this led the study authors to conclude that TRE may be one way to protect yourself—and ultimately boost your immune system.

Rejuvenate your metabolism

Of course, these new findings are impressive—but they’re not exactly the first of their kind.

Another recent study found that after just six weeks on a fasting diet, mice not only lost weight, but they also had higher levels of metabolically active, calorie-burning brown fat—and lower levels of calorie-storing white fat—along with more stable blood sugar and insulin levels.2

Further analysis revealed that fasting actually changed immune reactions within these fat cells—specifically, altering gene pathways involved in inflammation.

IF also seemed to boost a biochemical called vascular endothelial growth factor (VEGF). Among other things, VEGF is responsible for activating anti-inflammatory immune cells called macrophages, which stimulate the burning of stored fat.

Plus, as I’ve explained here before, fasting triggers a critical restorative process called autophagy, which “cleans up” damaged cells and generates newer, healthier replacements. This turbocharges your cells’ metabolic function, often within just 36 hours—an anti-aging benefit you’ll never achieve through textbook “dieting.”

In addition, studies on fasting human subjects show significant drops in a wide range of biomarkers linked to aging and heart risk: inflammation, blood pressure, LDL (bad) cholesterol, and short-chain fatty acids. And it achieves these metabolic benefits without any adverse effects, to boot.

But developing research suggests that there’s a lot more to gain here than better metabolic health…

Ward off cancer

As I shared in the April 2021 issue, studies show that fasting could actually be an effective complement to conventional breast cancer treatment.

And now, yet another new study on mice suggests that shrinking your daily eating windows may also slam the brakes on cancer altogether.

Researchers compared mice with postmenopausal hormone conditions. They found that obese mice with access to food for only eight hours had higher insulin sensitivity, lower insulin levels, steadier circadian rhythms, and reduced tumor growth.3

That’s compared to mice with a 24-hour access to either regular or low-fat diets. This just goes to show you that changing when you eat is just as important as changing what you eat, especially when it comes to disease prevention.

Safeguard your cognition

Science shows that fasting might also help to slow down age-related cognitive decline. (That is, if these latest animal study results apply to humans, too.)

Researchers from King’s College London looked at three different groups of female mice. One received a daily feeding of a standard diet. Another received a calorie-restricted diet. And a third group followed alternate day fasting (ADF), in which they were only fed every other day.

Over the course of the three-month study period, the fasting mice showed superior long-term memory retention compared to the other two groups. And when the scientists studied their brains, they also found increased expression of a longevity gene connected to the generation of new brain cells.4

The researchers plan to recreate this same study with human participants in the future. But in the meantime, there’s no reason you can’t reap the many potential benefits of fasting… starting TODAY…

Pick your preferred approach

The good news is, unlike some other health “trends” out there, it’s quite simple to incorporate fasting into your daily routine. And the beauty of IF is that there’s more than one way to do it—all of which are beneficial.

We already touched on two main approaches: TRE and ADF. (Again, TRE is when you limit your daily meals to specific eating windows—say, between noon and 6 p.m., which is what I do. And ADF is a bit more rigorous, where you fast every other day.)

You can also use the 5:2 approach, where any two days in a single week are your fasting days.

Just remember, fasting isn’t as much about caloric restriction as it is about timing. (Although, you still need to follow a healthy, balanced diet. Don’t go crazy reaching for anything in sight simply because it’s your non-fasting period.)

But if you struggle to choose the right foods, I recommend following a Mediterranean-type diet—like my very own A-List Diet. (Order yourself a copy from AListDietBook.com.)

In fact, this high-fat, low-carb diet will help maximize the potential of IF—by revving up metabolism and shedding unwanted toxins, right out of the gate. But as motivating as these benefits can be, there are still some psychological hurdles that can sabotage your success… especially if you don’t start with the right mindset.

Fasting is a natural state

I understand the mental struggle here: People feel comforted by food.

Food affects our mind, body, and soul. And the concept of “eating to live” versus “living to eat” doesn’t ring true for everyone—even myself, at times. (I personally love food tourism, and will eat plenty of foods I normally wouldn’t while traveling.)

Still, it helps to consider that we didn’t always have such an abundant food supply at our fingertips.

In fact, our ancestors would go days without eating a thing—perhaps just a nut or a berry, depending on the time of the year. So evolutionarily speaking, IF is as natural as it gets.

And by simply recognizing that fasting is actually way more normal for your body than eating 24/7, your body and mind will eventually start to reconnect when it comes to hunger.

The truth is, when our bodies crave food, sometimes we’re just craving love or a connection. (Or even something as simple as water.) So before you head to the kitchen, always take a moment to consider whether you’re actually hungry, or simply confusing a need to eat with boredom, loneliness, or dehydration.

If you’re not sure how to differentiate those feelings, allow me to offer some practical advice…

When it comes to boredom or loneliness…

  • Engage your mind in an activity or connect with a friend. Then, reevaluate your need to eat.

When it comes to dehydration…

  • Drink a full glass of water. Then, reevaluate your hunger.

Of course, I should warn you that it’s completely normal to feel hungry when you first begin your journey with IF. As with most things in life, your body needs some time to adjust. That’s why I often tell my patients to make it at least three full days before deciding whether IF is right for them.

In the meantime, if you need motivation, ask a friend or family member to do it with you. Or, download a fasting app—they are highly motivational, and if you allow alerts, they help you keep track of your fasting schedule, too.

Finally, think of this not as a “diet” with an end date, but rather your new lifestyle that your body is adapting to (and rest assured, it will). Getting over the initial hump will likely be more psychological than physiological.

And don’t forget to give yourself some grace along the way. Because once you fully experience the benefits of IF firsthand, believe me, there will be no going back.


  1. Moro T, et al.Time-restricted eating effects on performance, immune function, and body composition in elite cyclists: a randomized controlled trial. J Int Soc Sports Nutr 1765 (2020). https://doi.org/10.1186/s12970-020-00396-z 
  1. Li G, et al.Intermittent Fasting Promotes White Adipose Browning and Decreases Obesity by Shaping the Gut Microbiota. Cell Metab. 2017 Oct 3; 26(4): 672–685.e4.  
  1. Das M, et al.Time-restricted feeding normalizes hyperinsulinemia to inhibit breast cancer in obese postmenopausal mouse modelsNature Communications, 2021; 12 (1). 
  1. Dias GP, et al.Intermittent fasting enhances long-term memory consolidation, adult hippocampal neurogenesis, and expression of longevity gene KlothoMolecular Psychiatry, 2021; DOI: 10.1038/s41380-021-01102-4