People have long sought out pre-prepared foods with a long shelf-life; for example, Indigenous North Americans created <a href="https://www.sciencedirect.com/science/article/pii/S0309174021001029?casa_token=OE9wEDn8nekAAAAA:RHLs_vYAOnCSPIrmJD8M_4bT9qHDYbD3zjzViVpXX24qus9UE36c9Bfr74tFeExsMSQKAbnuGg">pemmican</a>, a mix of dried meat, tallow and berries, which settlers later found useful for long voyages and military expeditions. Quick eats looked pretty different by the 1990s, when <a href="https://www.washingtonpost.com/archive/lifestyle/food/1991/03/13/shake-up-in-the-diet-industry/dc9507d2-9e59-4de2-b544-c67bb2d317db/?utm_term=.1ee097393716">millions</a> of people were replacing meals with SlimFast drinks in hopes of quickly losing weight.

The Lure Of Quick Food: The Background

Online, you can find people who claim to have survived off of powder-based drinks such as Soylent and Huel for <a href="https://thehustle.co/soylent-what-happened-when-i-went-30-days-without-food/#:~:text=In%202013%2C%2024%2Dyear%2D,friends%20could%20buy%20the%20product.">weeks</a> (as Soylent’s founder, Rob Rhinehart, did) or <a href="https://medium.com/@Lewis_Grant/8-things-i-learned-eating-only-huel-for-6-months-ddad4bc42f9b">even</a> <a href="https://nextshark.com/alex-webber/">months</a> and <a href="https://www.reddit.com/r/soylent/comments/c0ac9n/drank_only_soylent_for_2_years_got_sent_to_the_er/">years</a> on end. While neither company recommends this tactic, some social media users see it as a welcome challenge and hope their personal experiments bring compelling results, including ramped-up physical fitness. Regardless of one’s liquid of choice, decades of meal-drinking ushers us into unprecedented territory. Most people naturally desire a varied diet that provides a range of sensory experiences.

Surviving On Protein Shakes

Scientists haven’t fully grasped how our diet evolved nor what exactly transpires in our bodies as we munch on burgers or pick through salads. But research has demonstrated that the diversity within one’s meals, including aspects like texture and taste, matters for our health. Experiments <a href="https://www.sciencedirect.com/science/article/pii/S0195666321000878">have</a> demonstrated that we tire of specific foods and tend to move on to new ones shortly after — consider why you may have room for dessert after a heaping savory meal. Humans <a href="https://www.sciencedirect.com/science/article/pii/S0195666317309017">may</a> have developed this behavior to ensure proper nutrient intake.

Missing Out on Variety (and Chewing)

Eliminating that fundamental variety-seeking that we have is not a good thing.It has been found that liquids don’t <a href="https://www.nature.com/articles/s41598-020-69504-y">make us feel as</a> satisfied as solids do. One possible explanation: “complex” liquids like smoothies and protein shakes <a href="https://health.clevelandclinic.org/how-long-does-it-take-to-digest-food/">leave</a> the stomach within 40 to 60 minutes — literal “fast food,”  while protein- and fat-rich solid meals can linger twice as long.

Drinking Instead Of Eating

Beyond feeling bored and perhaps hungry and disgruntled, what health effects come with exclusively drinking your meals? While weight-loss trials <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3322430/">have</a> <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3471207/">deemed</a> months-long liquid meal replacement plans as generally safe under medical supervision, there isn’t much data on the safety of a regimen filled with newer drinks like Soylent and Huel (apart from <a href="https://soylent.com/blogs/news/a-dietitian-s-view-on-clinical-research">small</a> <a href="https://huel.com/pages/a-summary-five-weeks-on-a-100-huel-diet">trials</a> carried out by the companies themselves).

Unnatural Way To Intake Food

Liquid diets are also ironically associated with dehydration, likely because people forget to drink enough water and aren’t getting much from food (which <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5084017/">provides</a> around 20 to 30 percent of the H2O we need)

Drinking More Water

As much progress as nutrition has made, we don’t understand all the complexities of what’s in different foods. And although some brands claim to stuff all of the necessary nutritional components into a bottle or powder, this feat may not actually be possible. We haven’t necessarily pinpointed all of the compounds that make certain foods healthy, and how they might work together to produce specific effects.Fruits and vegetables, for example, have all kinds of phytonutrients that aren’t necessarily even defined yet.

This Is No Magic Powder

When drinking supplements, it may be difficult to get enough fiber, which helps <a href="https://www.hsph.harvard.edu/nutritionsource/carbohydrates/fiber/#:~:text=Fiber%20helps%20regulate%20the%20body's,%2C%20whole%20grains%2C%20and%20beans.">regulate</a> hunger and blood sugar levels. Brands vary in their fiber content. The powders from Huel and Soylent offer a considerable 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 throwing back multiple per day. Drinking your food can also affect drug absorption, since thick liquids may <a href="https://www.ncbi.nlm.nih.gov/books/NBK554389/?_ga=2.185699489.968491278.1644862274-624627884.1644862274">delay</a> the dissolution of drugs.

The Missing Fiber

Exclusively slurping on SlimFast or Soylent also means that you’ll miss out on the joy of chewing. As it turns out, chewing is rewarding even when food is absent — consider why some people tear through packs of gum. Most importantly, munching <a href="https://www.mdpi.com/2072-6643/13/5/1391/htm">signals</a> the body to prepare for digestion, and longer chewing <a href="https://www.sciencedirect.com/science/article/pii/S0031938415300317#:~:text=Systematic%20review%20revealed%20an%20effect%20of%20chewing%20on%20food%20intake.&text=Increasing%20the%20number%20of%20chews%20per%20bite%20increased%20gut%20hormone%20release.&text=Mastication%20promotes%20satiety%20by%20influencing%20appetite%2C%20intake%20and%20hormone%20release.">might</a> even help us eat less.

The Joy Of Sitting And Slowly Chewing Food

Researchers have observed this phenomenon, known as sensory-specific satiety, among <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4146395/">animals</a> and <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5532562/">children</a> (who haven’t exactly memorized the food pyramid). Choosing to turn entirely to liquid meals when it isn’t otherwise necessary means overriding our hard-wired instincts. While meal replacement drinks may come in an increasing variety of flavours, you may encounter a relatively similar consistency and miss out on the crunch and flavours from a wider range of foods.

Sensory-Specific Satiety

Some powders and drinks boast all of the necessary nutrients a body needs — no grocery trips required. But it isn't clear how drinking our meals might affect our health.