Snack Day

What Is Snack Day?

Every year around June 21st (the exact date varies slightly) is "Snack Day." It traces back to a historical custom around the time of the summer solstice, in which leftover New Year's mochi was hardened, toasted, and eaten in a ritual called "hagatame" (tooth-hardening). Today, snack food makers and others promote the day as a time to enjoy snacking culture to build up energy for summer -- a fusion of the traditional habit of "chewing" with the modern culture of "enjoying" food.

The Historical Facts Behind "Hagatame" and the Summer Solstice

From ancient times, Japanese people have prayed for health by eating "hard things" at seasonal turning points.

• A Heian-era court ritual: In the Heian period, the imperial court held a "hagatame ceremony" at the summer solstice. By eating hard mochi or melon, people aimed to strengthen their teeth and, by extension, maintain overall health -- a practice considered one of the roots of today's "snack" culture.
• The custom of "chimaki" and wheat mochi: In some regions, people eat mochi or chimaki (rice dumplings) made from wheat at the summer solstice. This reflects a rational survival strategy of efficiently consuming carbohydrates to build up stamina ahead of the busiest farming season.

The Science of Snacking and Brain Performance

Snacking at the right time has real scientific benefits for brain function.

• Stabilizing blood sugar (the "second-meal effect"): Going too long without eating depletes the brain's glucose supply and lowers concentration. Having a small snack in the afternoon can help prevent a sharp rise in blood sugar at dinner -- the so-called "second-meal effect" -- contributing to mental stability throughout the day.
• How chewing activates the brain: True to the meaning of "hagatame" (tooth-hardening), chewing hard foods increases blood flow to the prefrontal cortex and hippocampus. Research shows this activates working memory and lowers levels of the stress hormone cortisol.

Interesting Facts About Snacks

• The original meaning of "snack": The word originally means a "light meal" or "something eaten quickly." In Japan it often refers to packaged snack foods, but scientifically and culturally, any nutrition consumed between meals counts as a snack.
• The science of the "crunch" in potato chips: Sound is a major factor in how delicious we find a snack. High-frequency crunching sounds stimulate the brain's reward system and amplify both appetite and satisfaction -- a phenomenon studied in psychoacoustics.
• Snack foods in space: Snack foods designed not to scatter crumbs (using special coatings, for example) have been developed for use in space. They're recognized for their value as comfort foods that ease psychological stress in extreme environments.
• The benefits of nuts as "natural snacks": The unsaturated fatty acids and vitamin E in nuts help reduce oxidative stress in the brain. In the context of "hard foods," nuts are a highly rational modern-day "scientific hagatame."
• The origin of "oyatsu" (Japanese for snack): The word comes from "yatsudoki," an old time designation for around 2-4 p.m. during the Edo period, when people commonly ate a snack. Biorhythmically, body temperature rises and metabolism becomes more active during this window, making it a scientifically suitable time for a snack.

Tips for Spending Snack Day

• To mark "June 21st, Snack Day," deliberately choose something with a satisfying crunch, like nuts or hard rice crackers, and chew thoroughly. This can improve blood flow to the brain and help clear away the "brain fog" that often builds up by this point in the fiscal year.
• Try "mindful snacking." Instead of mindlessly snacking while watching TV or scrolling your phone, focus on the taste and texture. Eating with all your senses increases satisfaction and can help prevent overeating.
• Give yourself permission to enjoy your favorite snacks as "nourishment for the soul." An occasional treat boosts dopamine, and incorporating moderate enjoyment -- not just restriction -- is essential for long-term mental health.
• Look into the traditional food culture of the summer solstice. Learning about regional customs like wheat mochi is an intellectually rewarding way to reconnect with the relationship between the seasons and the body.

A Satisfying Crunch and Rich Flavor with Every Bite Will Pleasantly Stir Your Brain and Set a New Rhythm for Tomorrow

June 21st marks the longest day of the year, full of light. Just as people in the Heian era chewed hard mochi while praying for health, we too can care for and nurture ourselves through what we eat each day. Has your busy schedule turned eating into just another task to get through? Today, savor a single snack mindfully, enjoying its texture and aroma. That solid, satisfying "crunch" can restore energy to your body and ease to your mind. Turn traditional wisdom into modern enjoyment, and step boldly into the bright light of early summer.