How to Chew 30 Seconds per Bite, and How to Stick With It

Being told to “chew well” isn’t much help if counting chews while you eat isn’t realistic. The moment you start counting, the meal turns into a task, and it usually ends within three days.

So here’s a way to set a boundary using time instead of count. Once a bite is in your mouth, you simply don’t swallow until 30 seconds have passed.

Up front, here’s how much effect to expect from this method: postprandial energy expenditure increases slightly, but not by an amount that will move your body weight on its own. The numbers come later.

Why Time Instead of Count

Counting chews pulls your attention away from the food and onto the count. Talking during a meal makes you lose track, and people usually give up partway through.

Setting a boundary by time removes the need to count. Use a phone timer for the first few times to get a feel for what 30 seconds is, and after that you’ll roughly match it by sense.

There’s another benefit: it naturally changes what foods you choose. White rice or udon won’t last 30 seconds in your mouth. Trying to make something last 30 seconds pushes you toward foods with more bite — roasted nuts, root vegetables, mushrooms, lean cuts of meat. This ends up being more sustainable than trying to directly increase your chew count.

Three Rules for Sticking With It

1. Limit It to the First Bite

Chewing for 30 seconds through an entire meal won’t last. Instead, set the rule as once a day, and only the first bite.

Slowing down at the start of a meal tends to slow the pace for the rest of it too. Changing just the entry point takes less effort than trying to change an entire meal.

2. Decide on a Way to Time It

30 seconds feels longer than you’d expect. Use a phone timer for the first week, then drop it once you’ve got a feel for it.

Without deciding on a tool ahead of time, you end up thinking “close enough is fine,” and often end up swallowing after around 10 seconds.

3. Let the Menu Buy the Time

Rather than relying on willpower to hold out for 30 seconds, it’s more reliable to let the food itself do the work.

What to change	What to actually do
Main dish	Choose cuts over ground meat, bone-in over fillets
Side dish	Add one dish of root vegetables, mushrooms, or seaweed
Snacks	Whole nuts instead of ground products
Soup	Cut ingredients into larger pieces

How Big an Effect to Expect

This is the part that tends to get exaggerated, so here are the numbers as they were actually measured.

Chewing increases postprandial diet-induced thermogenesis | Scientific Reports (2021) https://doi.org/10.1038/s41598-021-03109-x

This was a randomized crossover trial with 11 healthy young men. They consumed a 200 kcal liquid meal in 20mL portions, compared under three conditions.

Condition	What happened in the mouth	DIT over 90 minutes after eating
Control	Swallow as-is	3.4 kcal
Taste	Hold in mouth 30 seconds without chewing	5.6 kcal
Chew	Chew for 30 seconds, then swallow	7.4 kcal

DIT (diet-induced thermogenesis) is the energy consumed for digestion and absorption after eating. The chewing condition was significantly higher than the control (p < 0.05).

The difference is about 4 kcal over 90 minutes — roughly a sixth of a single bite of rice.

The middle row is easy to overlook. Simply holding food in the mouth without chewing already produced a 2.2 kcal increase, meaning more than half of the increase is explained not by chewing but by the time food spends in the mouth. That’s why this method is described as “don’t swallow for 30 seconds” rather than “chew for 30 seconds.”

Note that this study used a liquid meal. A prior study by the same authors using solid food is cited in the discussion, reporting 6 kcal for a 100 kcal solid meal and 15 kcal over 180 minutes for a 621 kcal meal.

What This Method Cannot Claim

• It cannot claim you will lose weight. This study did not measure body weight or body fat. The authors themselves use the word “speculate” in their conclusion
• It cannot claim you’ll feel full and eat less. This study found no significant difference in hunger or fullness ratings
• It cannot claim fat becomes easier to burn. There was no significant difference in respiratory exchange ratio or substrate oxidation
• The subjects were 11 young men, and measurements were taken over 90 minutes. Reproducing this in women, middle-aged or older adults, or people with obesity is outside the scope of this study

Summary

• Deciding not to swallow for 30 seconds is easier to stick with than counting chews
• Start with once a day, only the first bite
• Let the menu buy the time rather than relying on willpower
• The increase in energy expenditure is a few kcal per meal — not something to count on for moving your weight
• Still, the side effect of gravitating toward foods with more bite may end up mattering more in practice

Further Reading

• The Mechanism Behind Chewing and GLP-1 Secretion
• The Relationship Between Fast Eating and Obesity: Sorting Out What’s Been Reported

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※ This article is for informational purposes and is not a substitute for diagnosis or treatment.