This article was originally published on February 19, 2022.
People have long sought pre-prepared foods with a long shelf life; for example, the natives of North America created pemmican, dried meat mixture, tallow and berries that settlers later found useful on long journeys and military expeditions. Fast food looked quite different in the 1990s when millions of people were substituting meals with SlimFast drinks hoping for quick weight loss. Sales declined in the early 2000s darkened through other dietary options.
The latest iteration of convenient consumption: In 2014 and 2015, companies Soylent and Huel introduced powdered drinks with Silicon Valley types in mind—people who want to extend their hacking beyond computers and into their diets, consuming all the nutrients they need through multiple daily shakes. without the need for trips to the store.
Diet-oriented products like SlimFast predate the craze for trendier, more millennial-friendly drinks like Soylent and Huel. (Credit: Diana Vukane/Shutterstock)
Online you can find people who claim to have survived thanks to powdered drinks like Soylent and Huel for weeks (such as Soylentthe founder of Rob Reinhart) or even the month and years finally. While neither company recommends this tactic, some social media users see liquid meal replacements as a welcome challenge and hope that their personal experiments will lead to compelling results, including increased physical fitness.
It was the brainchild of Jason Hooper, a physical therapist and YouTuber who endured the 30 Day Huel Diet in which he got most of his calories by mixing powder into drinks. He found this useful for his busy schedule, which can include hours of rock climbing sessions. “It kind of simplified what is a huge part of our lives … that very big factor became very simple, so it allowed me to focus energy elsewhere,” he says.
Regardless of your liquid of choice, decades of drinking food are taking us into unprecedented territory. Research shows that most people naturally desire a varied diet that provides a range of sensory experiences.
“It seems very difficult. Basically, you’ll crave texture,” says Paul Smeets, a senior researcher at Wageningen University in the Netherlands who studies eating behavior. “Of course you can have all the nutrients you need intubated or swallowed, [but] it may not bring satisfaction.’
How liquid meal replacements affect our health
Scientists don’t fully understand how our diet evolved, nor what exactly happens in our bodies as we eat burgers or browse salads. But research shows that variety in food, including aspects such as texture and taste, matters for our health. Experiments have proven this we get tired of certain foods and tend to move on to new ones shortly after—think why you might have room for dessert after a hearty, savory meal. people they may have developed this behavior to ensure proper nutrient intake.
Researchers have even observed this phenomenon known as sensory specific satiety among children (who have not exactly memorized the food pyramid) and animals. So choosing to turn entirely to liquid meal replacements when not otherwise necessary is to ignore our hard-wired instincts. Although meal replacement drinks may come in a growing variety of flavors, you may encounter a relatively similar consistency and miss out on the crunch and flavors of a wider range of foods.
“Eliminating this basic demand for variety that we have is not a good thing,” says Barbara J. Rawls, a nutrition scientist at Penn State University who coined the term sensory specific satiety and has studied the process for more than four decades. “It’s so ingrained in all species and from a very young age.”
Liquids have been found not to they make us feel so satisfied as solids do. One possible explanation: Even “complex” liquids like smoothies and protein shakes leave the stomach faster than solid foods — literally, “fast food,” Smits says. Meanwhile, proteins and fatsrich solid meals can last twice as longaccording to the Cleveland Clinic.
Horace Fletcher (also known as “The Great Chewer”) pushed the benefits of chewing to its extreme in the early 20th century when he advised dieters to chew food until it reached a liquid consistency. (Source: Wikimedia Commons)
The extreme itchiness of SlimFast or Soylent also means you’ll miss out on the joy of chewing. As it turns out, chewing is rewarding even in the absence of food—consider why some people tear up packs of gum. most importantly, chewing cues body to prepare for digestion and longer chewing may even help we eat less.
Lindsay* suffers from multiple chronic illnesses and disabilities, including gastroesophageal reflux disease (GERD), which can make eating and cooking difficult. They add supplements to protein shakes for most snacks and other occasional meals while waiting for treatment, and sometimes add ice cream or coffee to mix things up. But this does not always make up for the lack of chewing. “Definitely not the most satisfying,” says Lindsay. “It’s not the same as sitting there and slowly chewing and eating.”
Do liquid meal replacements work?
Aside from feeling bored and maybe hungry and unsatisfied, what health effects come from drinking your food excessively? While trying to lose weight they have considered monthly liquid meal replacement plans are generally safe under medical supervision, there is not much data on the safety of a regimen filled with newer drinks like Soylent and Huel (except small trials carried out by the companies themselves).
Another challenge with drinking most (or all) of your food: it can be hard to get full fiber that helps regulate hunger and blood sugar levels. Brands vary in fiber content. Huel and Soylent powders offer a significant amount per serving, while Boost and Ensure drinks offer little to none. Meanwhile, drinks in the latter category can contain extremely high amounts of sugar, which add up if you’re downing several times a day. Drinking your food can also affect the absorption of the medicine, as thick liquids can slow down dissolution of drugs.
Liquid diets are also ironically linked to dehydration, possibly because people forget to drink enough water and don’t get much from food (which provides about 20 to 30 percent of H2O We need). Hooper says he did well, except for one day when he felt “pretty awful,” which he attributed to dehydration. A lab test showed there was elevated potassium levels, which can lead to from lack of fluids. He also consumes more than the recommended daily amount of potassium through approximately 2,700 daily calories from Huel products.
(Credit: Dan Leveille/Wikimedia Commons)
And although some brands claim to put all the necessary nutritional components into a bottle or powder, Rolls and Smeets say this feat may not actually be possible. We have not necessarily listed all the compounds that make certain foods healthy and how they may work together to produce specific effects.
“As much as there’s been progress in nutrition, we don’t understand the full complexity of what’s in different foods,” Rawls says. “Fruits and vegetables, for example, have all kinds of phytonutrients that haven’t necessarily even been defined yet.”
Not to mention, the act of eating is inherently social. While his comrades were digging into Domino’s Pizza one evening, Victor Nevarez sit he looked defeated with his bottle of strawberry soylent. Nevarez, a video producer who does cooking tutorials under the Internet username Shaquille, I tried a week-long diet made up exclusively of Soylent—he says he often felt run down and may have had digestive issues from drinking so much fat at once (sipping slowly is recommended).
He sees the voluntary shift from whole grains to Soylent as a reversal of antisocial behavior. “For someone to say, ‘No thank you, I don’t because I consume Soylent for all my meals,’ is not going to be easy to understand,” he says.
A useful alternative
For the three months in 2019 when Bethany* drank all her meals, she didn’t have much of a choice due to her lack of participation in group meals. After catching a virus two years earlier, she developed gastroparesis, a condition that causes partial paralysis of the stomach and can slow or stop the movement of food into the small intestine. This made it difficult to eat without throwing up, and she had few options while waiting to see a specialist.
So she counted of Boost and Ensure drinks for sustenance, along with some Gatorade and salads—all the while working toward his Ph.D. “I don’t recommend it,” she says, and the routine leaves her with “crap” energy levels and barely enough food to survive.
Contrary to the popular view of users of liquid meal replacements as overzealous software engineers or fad diets, these products can serve as a last resort for people who cannot eat solid foods for various reasons. Nevarez says he was surprised to learn from comments on his Soylent video that people were using it while recovering from surgery and eating disorders.
Although more diverse liquid meal replacement options have emerged in the past few years, Lindsey and Bethany point to the fact that people with disabilities and chronic illnesses would benefit from more beverages without common allergens such as soy and dairy that are prevalent in such products along with reduced sugar levels.
In the future, Bethany also hopes to see more rigorous evidence behind different products to help bridge the gap when solid food isn’t an option. “You try to get things for medical reasons, but you end up stepping into either the toxic diet culture or the wellness manipulation of pseudoscience,” she says.
*Some sources’ last names have been omitted to ensure anonymity.