A diet guru explains why you should eat dinner at 2 pm

We talk a lot about what to eat, but what about when?

Ceramic bowl with vegetables
Hermes Rivera / Unsplash
  • A recent study shows that over 50% of people eat over the course of fifteen hours every day.
  • Another study shows that restricting meals to an eight-hour window had profound effects on weight loss.
  • Dr. Jason Fung advocates for earlier dinners in a tighter feeding window.

What you should eat has been the focus of fad diets for decades. Less discussed is when. Thanks to the rise of the ketogenic diet, intermittent fasting has become trendy. Getting into ketosis is possible through a high-fat diet, yet is beneficially aided by fasting. While the science is up for debate on the efficacy of long-term usage of high-fat intake, limiting the duration of your grazing habits seems to have important benefits.

Grazing is one word for it. As nephrologist Dr. Jason Fung, the founder of Intensive Dietary Management Program who specializes in type 2 diabetes and intermittent fasting, points out, one study revealed that the median daily intake of food was 14.75 hours a day.

In fact, over half of the people in that study ate for over 15 hours every day, meaning if they their first meal (or snack) was consumed at 8 am, their last meal wouldn't occur until after 11 pm. These data come from Salk Institute professor Satchin Panda's study, which was tracked by a smartphone app.

Over the course of three weeks, healthy, non-shift workers tracked their eating habits by pressing a button delivered by the app. In total, 26,676 intake events occurred: 22 percent were water, 28 percent pre-packaged food items, and 50 percent mixed meals with multiple items. Another follow-up study tracked participants for sixteen weeks. Less than 25 percent of calories occurred before noon, with 37.5 percent eaten after 6 pm. This is a problem, Fung says.

First off, the least frequent eaters in Panda's study consumed food an average of 3.3 times a day, close to the basic folk wisdom of "three square meals." They only represented 10 percent of the population. That means 90 percent ate more than 3.3 times a day. In fact, many ate a lot more.

Despite what you'll read on holistic blogs everywhere, the type of food was not nearly as relevant as the time that they were actually eating. Fung continues,

When those overweight individuals eating more than 14 hours per day were simply instructed to curtail their eating times to only 10 to 11 hours, they lost weight (average 7.2 lbs, or 3.3 kg) and felt better even though they were not instructed to overtly change when they ate.

Fung cites another study that traced a restricted feeding schedule, known as early Time Restricted Feeding (eTRF). Two groups ate the exact same diet. One consumed their meals between 8 am and 8 pm, while the other chowed down between 8 am and 2 pm. All volunteers in this study were pre-diabetic.

The benefits were huge. Mean insulin levels dropped significantly, and insulin resistance dropped as well. Insulin is a driver of obesity, so merely changing the meal timing and restricting the number of hours you ate, and also by moving to an earlier eating schedule, produced huge benefits even in the same person eating the same meals. That's astounding. Even more remarkable was that even after the washout period of seven weeks, the eTRF group maintained lower insulin levels at baseline. The benefits were maintained even after stopping the time restriction. Blood pressure dropped as well.

Fung notes that green tea is an important tool in helping those trying to fast.

rawpixel / Unsplash

Fung argues that while it's not actually difficult to fast for sixteen or eighteen hours a day—I concur, having tried it for two months; your body quickly adjusts—eating dinner at 2 pm presents a serious challenge to the way our society is structured.

What Fung is really interested in is changing the narrative around diet. Sure, too much sugar is not good; fresh produce and whole grains are most often a better decision than processed foodstuffs littered with preservatives. Not every body can handle too much caffeine, which affects sleeping patterns, which affects metabolism, which leads to obesity. Nuance is important.

Fung is advocating is for a broader discussion of when. Given all we've been learning about the importance of circadian rhythm (which can now be measured in our your blood), we're discovering that even a few hours of fasting a day can have profound consequences. Magical elixirs might not help you lose weight, but deciding not to drink them just might.

--

Stay in touch with Derek on Twitter and Facebook.

A landslide is imminent and so is its tsunami

An open letter predicts that a massive wall of rock is about to plunge into Barry Arm Fjord in Alaska.

Image source: Christian Zimmerman/USGS/Big Think
Surprising Science
  • A remote area visited by tourists and cruises, and home to fishing villages, is about to be visited by a devastating tsunami.
  • A wall of rock exposed by a receding glacier is about crash into the waters below.
  • Glaciers hold such areas together — and when they're gone, bad stuff can be left behind.

The Barry Glacier gives its name to Alaska's Barry Arm Fjord, and a new open letter forecasts trouble ahead.

Thanks to global warming, the glacier has been retreating, so far removing two-thirds of its support for a steep mile-long slope, or scarp, containing perhaps 500 million cubic meters of material. (Think the Hoover Dam times several hundred.) The slope has been moving slowly since 1957, but scientists say it's become an avalanche waiting to happen, maybe within the next year, and likely within 20. When it does come crashing down into the fjord, it could set in motion a frightening tsunami overwhelming the fjord's normally peaceful waters .

"It could happen anytime, but the risk just goes way up as this glacier recedes," says hydrologist Anna Liljedahl of Woods Hole, one of the signatories to the letter.

The Barry Arm Fjord

Camping on the fjord's Black Sand Beach

Image source: Matt Zimmerman

The Barry Arm Fjord is a stretch of water between the Harriman Fjord and the Port Wills Fjord, located at the northwest corner of the well-known Prince William Sound. It's a beautiful area, home to a few hundred people supporting the local fishing industry, and it's also a popular destination for tourists — its Black Sand Beach is one of Alaska's most scenic — and cruise ships.

Not Alaska’s first watery rodeo, but likely the biggest

Image source: whrc.org

There have been at least two similar events in the state's recent history, though not on such a massive scale. On July 9, 1958, an earthquake nearby caused 40 million cubic yards of rock to suddenly slide 2,000 feet down into Lituya Bay, producing a tsunami whose peak waves reportedly reached 1,720 feet in height. By the time the wall of water reached the mouth of the bay, it was still 75 feet high. At Taan Fjord in 2015, a landslide caused a tsunami that crested at 600 feet. Both of these events thankfully occurred in sparsely populated areas, so few fatalities occurred.

The Barry Arm event will be larger than either of these by far.

"This is an enormous slope — the mass that could fail weighs over a billion tonnes," said geologist Dave Petley, speaking to Earther. "The internal structure of that rock mass, which will determine whether it collapses, is very complex. At the moment we don't know enough about it to be able to forecast its future behavior."

Outside of Alaska, on the west coast of Greenland, a landslide-produced tsunami towered 300 feet high, obliterating a fishing village in its path.

What the letter predicts for Barry Arm Fjord

Moving slowly at first...

Image source: whrc.org

"The effects would be especially severe near where the landslide enters the water at the head of Barry Arm. Additionally, areas of shallow water, or low-lying land near the shore, would be in danger even further from the source. A minor failure may not produce significant impacts beyond the inner parts of the fiord, while a complete failure could be destructive throughout Barry Arm, Harriman Fiord, and parts of Port Wells. Our initial results show complex impacts further from the landslide than Barry Arm, with over 30 foot waves in some distant bays, including Whittier."

The discovery of the impeding landslide began with an observation by the sister of geologist Hig Higman of Ground Truth, an organization in Seldovia, Alaska. Artist Valisa Higman was vacationing in the area and sent her brother some photos of worrying fractures she noticed in the slope, taken while she was on a boat cruising the fjord.

Higman confirmed his sister's hunch via available satellite imagery and, digging deeper, found that between 2009 and 2015 the slope had moved 600 feet downhill, leaving a prominent scar.

Ohio State's Chunli Dai unearthed a connection between the movement and the receding of the Barry Glacier. Comparison of the Barry Arm slope with other similar areas, combined with computer modeling of the possible resulting tsunamis, led to the publication of the group's letter.

While the full group of signatories from 14 organizations and institutions has only been working on the situation for a month, the implications were immediately clear. The signers include experts from Ohio State University, the University of Southern California, and the Anchorage and Fairbanks campuses of the University of Alaska.

Once informed of the open letter's contents, the Alaska's Department of Natural Resources immediately released a warning that "an increasingly likely landslide could generate a wave with devastating effects on fishermen and recreationalists."

How do you prepare for something like this?

Image source: whrc.org

The obvious question is what can be done to prepare for the landslide and tsunami? For one thing, there's more to understand about the upcoming event, and the researchers lay out their plan in the letter:

"To inform and refine hazard mitigation efforts, we would like to pursue several lines of investigation: Detect changes in the slope that might forewarn of a landslide, better understand what could trigger a landslide, and refine tsunami model projections. By mapping the landslide and nearby terrain, both above and below sea level, we can more accurately determine the basic physical dimensions of the landslide. This can be paired with GPS and seismic measurements made over time to see how the slope responds to changes in the glacier and to events like rainstorms and earthquakes. Field and satellite data can support near-real time hazard monitoring, while computer models of landslide and tsunami scenarios can help identify specific places that are most at risk."

In the letter, the authors reached out to those living in and visiting the area, asking, "What specific questions are most important to you?" and "What could be done to reduce the danger to people who want to visit or work in Barry Arm?" They also invited locals to let them know about any changes, including even small rock-falls and landslides.

Your genetics influence how resilient you are to the cold

What makes some people more likely to shiver than others?

KIRILL KUDRYAVTSEV/AFP via Getty Images
Surprising Science

Some people just aren't bothered by the cold, no matter how low the temperature dips. And the reason for this may be in a person's genes.

Keep reading Show less

Harvard study finds perfect blend of fruits and vegetables to lower risk of death

Eating veggies is good for you. Now we can stop debating how much we should eat.

Credit: Pixabay
Surprising Science
  • A massive new study confirms that five servings of fruit and veggies a day can lower the risk of death.
  • The maximum benefit is found at two servings of fruit and three of veggies—anything more offers no extra benefit according to the researchers.
  • Not all fruits and veggies are equal. Leafy greens are better for you than starchy corn and potatoes.
Keep reading Show less
Quantcast