But it’s important not to completely neglect your fruits and vegetables, and not just for the vitamins and other nutrients they provide. Yup: we're talking about fiber.
The amount of fiber in a person’s diet can affect weight, blood sugar, insulin regulation, and gut health. But scientists still don’t completely understand how fiber makes all this happen. A pair of 2017 studies in the journal Cell attempt to understand why fiber is so important. In a study with mice, researchers found that just three days on a low fiber diet can change gut microbe diversity, and alter the protective mucus-y layer that forms a sort of seal between your intestinal cells and the surrounding food and bacteria.
Humans can’t actually digest and use any of the fiber we eat. It just passes on through. So why is it so good for us?
Most of the food we eat is quickly broken down in the high-acidity environment of the stomach, then absorbed there and in our small intestines. But fiber survives this entire process and makes its way to the colon unscathed, where it's feasted upon by resident bacteria of the large intestine. Consequently, the more fiber we eat, the more energy we can provide our microbes, and the more abundant and diverse they become. Our microbes then, in turn, do all sorts of good things for us—like help us digest certain foods, regulate our metabolism and blood sugar, and maintain a healthy weight. Research suggests that the healthiest gut microbiome is one full of a diverse flourish of flora, so it follows that high doses of fiber help keep us healthy.
But what happens if you take a few days—or even a week—off your fastidious fiber foraging in favor of more frivolous feasts? Researchers found that after just three to seven days on a low-fiber diet, mice microbiomes changed and shrank, becoming less diverse as various bacterial species died off. Additionally, the key layer of mucus that protects the lining of the intestine started to break down. That allows bacteria to reach the gut lining, triggering widespread inflammation which can contribute to metabolic diseases like diabetes and obesity.
So-called Western diets, featuring more heavily processed foods that are thus lower in fiber, have long been associated with a slew of health issues like diabetes, obesity, and inflammatory diseases (like IBD). And research indicates that many people with these conditions have altered microbial diversity. The new study shows just how quickly these microbes start dying off—just one week after a dietary shift.
When researchers switched the mice onto diets with lots of a fiber called inulin, the change did create a more diverse and microbe-friendly gut. Unfortunately, their mousy microbiomes never quite reached the level of diversity seen at the start of the study.
What does this mean for me?
Fiber is really, really important. Although it’s fine to indulge in foods that are not considered the healthiest, we should probably never completely neglect fiber. Anxiety over packing on a pound or two might have you counting calories and denying yourself cookies, but you'd be much better off focusing your efforts on keeping fruits and veggies in the mix as you enjoy treats in moderation.
And while you're at it, keep high-fiber diets in your heart every day of the year. Americans, on average, consume just 15 grams of fiber daily, which is something like half the recommended amount. Even if you meet that recommended threshold, you can do better: a study done this year analyzing the diets of the Hadza, a hunter-gatherer tribe in Africa, found that they eat, on average, 100 grams of fiber a day. They tend to live long and healthy lives, and they definitely have healthier guts.
Of course, the entire world can’t go back to a hunter-gatherer lifestyle. Instead, researchers are figuring out which microbes help our guts (and how) so we can harness them to treat and reverse certain diseases. But in the meantime, you should definitely eat more fruits and vegetables.
Check out 10 up-and-coming healthy fast food chains to help keep you on track while traveling below!
10 up-and-coming healthy fast food chains
10 up-and-coming healthy fast food chains
Leon — a European fast food chain that's coming to the US
The London-based fast-food chain Leon offers wraps, salads, sandwiches, and bowls made from fresh ingredients.
Launched in 2004, Leon now has almost 50 restaurants in the United Kindom and Netherlands. After a $31 million funding boost in 2017, the company announced it will expand to the US market.
Leon founders John Vincent, Henry Dimbleby, and Allegra McEvedy have said that their long-term goal is to become more valuable than McDonald's.
Salad and Go — A drive-thru salad chain
Salad and Go sells 48-ounce salads for around $6, as well as soups, smoothies, and breakfast items for around $4.
The brand is trying to rival more established drive-thru chains by making the ordering experience fast and convenient, cofounder Roushan Christofellis told Business Insider.
Since launching in the fall of 2016, Salad and Go now has six locations in Arizona, with plans to open eight more by 2018 and to expand elsewhere in the US by 2020.
LYFE Kitchen — A healthy chain backed by Oprah's former personal chef
Founded in 2011 in Palo Alto, California, LYFE has 20 locations in six states (California, Colorado, Illinois, Nevada, Tennessee, and Texas).
While the chain doesn't explicitly brand itself as healthy, everything on the menu contains less than 600 calories and 1,000 mg of sodium, and the dishes are free of high-fructose corn syrup, butter, cream, trans fats, MSG, and preservatives. Most items cost less than $10.
As noted by First We Feast, LYFE is backed by Art Smith, Oprah’s former personal chef, who has also appeared on "Top Chef."
Veggie Grill — A vegan chain that claims its burger tastes better than a Big Mac
The vegan chain Veggie Grill serves burgers primarily made of pea protein, while its "chicken" sandwiches contain soy, pea, and wheat protein. Prices range from $3.50 to $11.50.
The chain has 28 locations, all of which are in California, Washington, and Oregon. In late 2016, the chain announced it will expand nationally after getting $22 million in funding from investors. By 2020, Veggie Grill plans to double in size.
"Today’s consumer is more mindful and aware that eating a diet made up primarily of veggies, fruits, grains and nuts is better for you," CEO Steve Heeley told Business Insider. (Unsurprisingly, Heeley is a vegan himself.)
Eatsa — An automated vegetarian chain
At the vegetarian chain Eatsa, customers place their orders on iPads and pick up their food from automated cubbies. Human workers prepare everything in the back.
Specializing in quinoa bowls that cost around $7, the chain's meals range from 450 to 700 calories.
Currently, Eatsa (which debuted in 2015) has four locations in San Francisco and Los Angeles. In November 2016, it added a DC location and opened its first New York City location in December.
Dig Inn — A farm-to-table eatery
With a menu that emphasizes locally sourced vegetables, Dig Inn offers items like maple and sriracha-glazed Brussels sprouts and poached wild salmon. Diners order pre-made main dishes and sides at a counter, which are placed in compostable boxes.
Since its launch in 2011, the farm-to-table chain has opened 14 locations in New York City and one in Boston. Dig Inn's CEO Adam Eskin told BI that the company plans to open more Massachusetts locations and add others in a third state by 2018.
Dig Inn forms partnerships with local farmers, which allows it to keep its prices relatively low, Eskin said. However, a plate from Dig Inn generally costs between $8-$11, which is more expensive than most food from McDonald's or Burger King. (However in New York City, where real estate prices are among the highest in the country, a McDonald's Big Mac meal costs around $8.)
The Kitchenette — A grab-and-go joint where most items cost $5
In August 2016, Kimbal Musk (yes, he's Elon's brother) launched a fast food restaurant that serves sandwiches, soups, and salads — the majority of which cost $4.95. Called the Kitchenette, it's located inside the visitor's center at Shelby Farms Park, a 4,500-acre urban park and conservancy in Memphis, Tennessee.
The grab-and-go spot is part of Musk's larger chain of restaurants, called the Kitchen, which strives to use produce and meat from local purveyors. Musk plans to launch more Kitchenette locations within Memphis and eventually nationwide, though there's no firm timeline yet.
Freshii — A plant-based chain that's been around for 10 years
Freshii, a Canadian fast food franchise founded in 2005, offers salads, wraps, and bowls, the majority of which are under 700 calories and cost $7. It boasts more than 300 locations worldwide and is one of America's most popular healthy fast food chains. In the past few years, new locations have opened inside airports, stadiums, and Target stores.
In 2015, after McDonald's announced its menu improvements, Freshii's CEO Matthew Corrin sent an open letter to McDonald's, in which he offered to partner with the fast-food giant and pushed the chain to serve healthier food.
Everytable — A chain that changes its prices based on the average income in the neighborhood where it's located
Everytable, which launched its first Los Angeles location in 2016, adjusts its prices depending on what its local customers can afford.
The South LA location (where households earn a median salary of $30,882), for example, offers salads and bowls for less than $4.50. In early 2017, Everytable opened a second location in downtown LA (where the median salary is $99,990), which offers the same items for around $8. Both stores' ingredients will be sourced from local purveyors, but the idea is that sales in wealthier neighborhoods can partially subsidize operations in lower-income areas.
Everytable's cofounders, Sam Polk and David Foster, told BI they plan to expand the chain to more LA neighborhoods and eventually to other cities around the US.
LocoL — A California eatery where everything costs $6 or less
LocoL, a fast food concept spawned by famed chefs Roy Choi and Daniel Patterson, offers a new take on traditional fast food.
The chain's dishes contain more calories than, say, a salad, but everything is made with high-quality, locally sourced, whole ingredients. In LocoL's cheeseburgers, for example, cooked grains and tofu make up 30% of the beef patties. Its chicken nuggets also contain fermented barley. Instead of soda, fruity aguas frescas are made in-house every day.
The chain, which launched in 2016, currently has three permanent locations and an array of food trucks in Los Angeles. In coming years, Choi and Patterson hope to have nine locations nationwide, including a coffee shop and a kitchen where their staff can prepare the trucks' food off-site, according to Eater.