Time-Restricted Eating: The One Simple Trick That Might Help You Lose Weight

iStock
iStock

You’ve likely heard personal trainers or nutritionists say it’s important to eat breakfast right when you wake up to jump-start your metabolism and begin the day with your engine revving. But a new diet trend called time-restricted eating, which is basically a form of fasting in which you refrain from eating for several hours of the day, flips that thinking on its head: On this plan, you could be awake for several hours before you eat anything.

It might sound counter to conventional dieting advice (not to mention difficult to stick to), but research has found it can be an effective way to stay slim—even if you don’t restrict what you’re eating. Read on for more about the science behind this craze and whether it might be a good meal strategy for you.

THE BASICS

To follow a time-restricted diet (which is also known as intermittent fasting), you can continue eating the same foods you normally do, you just only eat them during a certain number of hours of the day. You start by restricting all eating to an 11- or 12-hour period—so, if you have breakfast at 8 a.m., you’ll have to set forks down by 7 or 8 p.m. You’re allowed to drink water, coffee, or tea (with no milk or sugar) during the fasting periods between bedtime and in the a.m., but you have to steer clear of ingesting anything else.

If you want to give it a shot, it’s a good idea to start slowly, advises Jaclyn Jacobsen, a nutritionist with the Vitamin Shoppe. Begin by fasting for about 12 hours of the day (including the time you sleep). Once you get used to it and it feels fairly easy, try dialing it back even further, allowing yourself to eat only 10 or maybe even eight hours of the day. “Theoretically, the longer you fast, the more fat you are burning for energy in the absence of glucose,” Jacobsen says.

THE BENEFITS

A few animal-based studies suggest that time restriction might be all that’s necessary to help you slim down. Recent research published in the journal Cell Metabolism, for instance, found that this rule can help you maintain a healthy weight—even if you cheat on the weekends. And the study also found that it didn’t matter what you eat: If you eat it during a small window of the day, you’ll still be slimmer than if you eat it at all hours.

In addition to helping you maintain a healthy weight, restrictive eating might also help you have less inflammation and lower your risk of diabetes, heart disease, and other chronic illnesses. Longer fasting periods and less eating in the evening may lower inflammation and risk of breast cancer as well, according to a study published in PLoS One.

It makes your body burn fat more efficiently, too, says Jacobsen: “When glucose is absent, the body will break down fat stores into free fatty acids for energy. This use of free fatty acids enhance fat burning as you are using stored fat for fuel.” And though it may seem contradictory, time-restriction can actually make you less hungry—by normalizing your body’s level of ghrelin (the "hunger hormone"). “Fasting helps the regulation of this hormone so we feel hungry only when we actually need to eat,” Jacobsen says.

And this is where the trainer's advice to "jump-start" your metabolism by eating breakfast takes a beating: “Much research has shown that your metabolic rate actually increases when fasting, so you burn calories more efficiently when you do start eating,” Jacobsen says. Your metabolic function won’t decrease significantly, she says, unless you go at least three full days without eating.

THE DRAWBACKS

Cutting back on the hours you’re allowed to eat might not come naturally. Some people will adapt easily and get used to eating during a small window of time after just a few days, according to Jacobsen, while others will take up to a month to fully adjust. And you might never feel fully acclimated.

Another big drawback: It might not get you the slim-down results you want. “Some individuals, especially women, are very sensitive to any type of hormonal changes in the body, so fasting may offer no additional benefit when compared to eating a whole-foods diet,” she says.

THE VERDICT

You’ll likely see better weight-loss results and feel better if you make healthier food choices in general, Jacobson says; whether you’re doing time-restricted eating or not, she recommends a diet consisting of about 80 percent whole foods (like vegetables, whole grains, and lean protein) and letting yourself indulge in treats 20 percent of the time.

So intermittent fasting might be worth a shot, but keep in mind that skipping midnight snacks or early-morning coffee with cream might not necessarily be ideal for you. “There is no ‘one size fits all’ when it comes to this concept or any other health-related concept,” Jacobsen says. “Nutrition is so individual, so what works for one group of people, may not work for others. It’s all trial and error.”

Learn Travel Blogging, Novel Writing, Editing, and More With This $30 Creative Writing Course Bundle

Centre of Excellence
Centre of Excellence

It seems like everyone is a writer lately, from personal blog posts to lengthy Instagram captions. How can your unique ideas stand out from the clutter? These highly reviewed courses in writing for travel blogs, novel writing, and even self-publishing are currently discounted and will teach you just that. The Ultimate Creative Writing Course Bundle is offering 10 courses for $29.99, which are broken down into 422 bite-sized lessons to make learning manageable and enjoyable.

Access your inner poet or fiction writer and learn to create compelling works of literature from home. Turn that passion into a business through courses that teach the basics of setting up, hosting, and building a blog. Then, the social media, design, and SEO lessons will help distinguish your blog.

Once you perfect your writing, the next challenge is getting that writing seen. While the bundle includes lessons in social media and SEO, it also includes a self-publishing course to take things into your own hands to see your work in bookshops. You’ll learn to keep creative control and royalties with lessons on the basics of production, printing, proofreading, distribution, and marketing efforts. The course bundle also includes lessons in freelance writing that teach how to make a career working from home.

If you’re more of an artistic writer, the calligraphy course will perfect your classical calligraphy scripts to confidently shape the thick and thin strokes of each letter. While it can definitely be a therapeutic hobby, it’s also a great side-hustle. Create your own designs and make some extra cash selling them as wedding placards or wall art.

Take your time perfecting your craft with lifetime access to the 10 courses included in The Ultimate Creative Writing Course Bundle. At the discounted price of $29.99, you’ll have spent more money on the coffee you’re sipping while you write your next novel than the courses themselves.

 

The Ultimate Creative Writing Course Bundle - $29.99

See Deal

At Mental Floss, we only write about the products we love and want to share with our readers, so all products are chosen independently by our editors. Mental Floss has affiliate relationships with certain retailers and may receive a percentage of any sale made from the links on this page. Prices and availability are accurate as of the time of publication.

Winter is Coming: Why Some People Seem to Feel Colder Than Others

Work blanket? Check. Hot tea? Check. Writing gloves? Check.
Work blanket? Check. Hot tea? Check. Writing gloves? Check.
shironosov/iStock via Getty Images

For a few weeks a year, as winter turns into spring, or summer gives way to fall, people in heavy coats coexist with those in sandals and shorts. Similarly, in an office where the thermostat is set at 74°F, some workers will be comfortable in short sleeves, while others will be wearing sweaters and scarves.

Underlying this disagreement are the different ways people perceive cold—and scientists are still trying to understand them.  

Men, Women, and Metabolism

In work settings, men and women often have different opinions about the ideal temperature. A 2019 study found that women performed better in math and verbal tasks at temperatures between 70°F and 80°F, while men did better below 70°F. The researchers proposed that gender-mixed workplaces might boost productivity by setting the thermostat higher than the current norm (which the Occupational Safety and Health Administration suggests should be between 68°F and 76°F).  

The discrepancy has a known physical basis: Women tend to have lower resting metabolic rates than men, due to having smaller bodies and higher fat-to-muscle ratio. According to a 2015 study, indoor climate regulations are based on an “empirical thermal comfort model” developed in the 1960s with the male workers in mind, which may overestimate female metabolic rates by up to 35 percent. To compound the problem, men in business settings might wear suits year-round, while women tend to have more flexibility to wear skirts or sundresses when it's warm outside.

Culture and the Cold

Cultural factors are also involved. European visitors are habitually alarmed by the chilly temperatures in American movie theaters and department stores, while American tourists are flabbergasted at the lack of air conditioning in many European hotels, shops, and offices. The preferred temperature for American workspaces, 70°F, is too cold for Europeans that grew up without the icy blast of air conditioners, Michael Sivak, a transportation researcher formerly at the University of Michigan, told The Washington Post in 2015.

The effects of cultural change on the human ability to withstand extreme temperatures can be dramatic. In the 19th century, 22 percent of women on the Korean island of Jeju were breath-hold divers (haenyeo). Wearing thin cotton bathing suits, haenyeo dove nearly 100 feet to gather shellfish from the sea floor, holding their breath for more than three minutes in each dive. In winter, they stayed in 55°F-57°F water for up to an hour at the time, and then warmed up by the fire for three of four hours before jumping back in.

In the 1970s, haenyeo starting wearing protective wet suits. Studies conducted between the 1960s and the 1980s showed that their tolerance for cold diminished [PDF].

Blame Your Brain

Beyond the effects of cultural practice and body composition, scientists have started to identify the cognitive factors that influence our temperature perception. It turns out that what feels unpleasantly cold versus comfortably chill is partly in our own minds.

One example is the phenomenon described as “cold contagion.” A 2014 study asked participants to view videos of people immersing their hands in visibly warm or cold water. Observers not only rated the hands in cold water as cooler than those in hot water, but their own hands became cooler when watching the cold-water videos. There was no comparable effect for the warm water videos, however. The findings suggest that we may feel colder when surrounded by shivering people at the office than if we're there by ourselves, even when setting the thermostat at the same temperature in both cases.

Other studies highlight the psychological aspects of temperature perception. Experimental participants at the Institute of Biomedical Investigations in Barcelona, Spain, watched their arms become blue, red, or green by means of virtual reality, while the neuroscientist Maria Victoria Sanchez-Vives and her team applied heat to their actual wrists. As the temperature increased, participants felt pain earlier when their virtual skin turned red than when it turned blue or green.

Subjectivity in temperature perception has led to some creative treatments for burn patients. In the 1990s, Hunter Hoffman, David Patterson, and Sam Sharar of the University of Washington developed a virtual-reality game called SnowWorld, which allows patients in hospital burn units to experience virtual immersion in a frozen environment. Amazingly, playing SnowWorld counteracted pain during wound care more effectively than morphine did.

“The perception of temperature is influenced by expectations,” Sanchez-Vives tells Mental Floss. “Putting one’s hand inside a virtual oven is perceived as ‘hot,’ while sticking one’s hand into a virtual bucket filled with iced water is perceived as ‘cold,’ despite being at room temperature in each scenario.”

In other words, if you expect to feel cold walking into the office or out on the street, chances are that you will.