“Nature will castigate those who don’t masticate”
“Drink your food and chew your water”
These two phrases come from different nutritionists, whose view on the importance of chewing your food ( a lot) matters – a lot.
But what does it mean? What can you gain, or lose, from more thoroughly chewing food? Can it really help you eat less and cut your calories down as much as many claim?
In brief, aside from some special cases like nuts, chewing more should help you cut calorie intake. Chewing more has many effects on feeding behavior, appetite, and digestion – some good and some questionable, depending on your goals.
Why You Should Chew More & Eat Slower
In one study, participants were fed small (5 grams) or large (15 grams) mouthfuls of chocolate custard, and allowed to chew for 3 or 9 seconds prior to swallowing1. Then, for the next 30 minutes they were allowed to consume as much or as little chocolate custard as they wanted. The results showed that significantly less chocolate custard was eaten if they were initially fed small bites and/or allowed to chew it more prior to swallowing. In fact, comparing the two extreme conditions (small bite size & longer chew time vs. large bite size & shorter chew time), the difference in subsequent intake amounted to 294 vs. 447 kcal – that’s a 52% increase!
Similarly, another study showed that subjects assigned to chew their food 40 times ate 11.9% less than those assigned to chewing it 15 times2.
Collectively, these data suggest that taking the time to enjoy your food, eat slowly & savor it, can cause you to eat less. Eating slower may be particularly important because it takes our brain and stomach about 20 minutes to register feelings of fullness.
The Curious Case Of Nuts
Nuts are a phenomenally complex food, consisting of a blend of proteins, fats, carbs, and fibers, all packaged tightly into small calorie-dense bundles. And the release of those calories may depend more on how well you chew than on anything else.
In one study, participants were given roughly 2 ounces of almonds per day and instructed to chew 10, 25, or 40 times3. The results showed that significantly less fat was absorbed when the almonds were chewed only 10 times. The subjects who chewed more reported feeling fuller and less hungry, but this may be due as well to the fact that they absorbed more calories, not only that they chewed their food more.
These findings were confirmed in another study, albeit indirectly. In this one, subjects were given either peanuts, peanut butter, or peanut oil, and fat absorption was subsequently monitored4. The peanuts most closely resembled the 10-chew condition in the almond study, peanut butter the 25-chew, and peanut oil the 40-chew condition. And the results were similar – peanut ingestion was associated with significantly less, and peanut oil significantly more absorption of the fat in peanuts. What this study suggests it that when it comes to nuts, sticking to whole nuts may result in less calorie absorption than nut butters and nut oils. While this is not a direct, chew vs less chew scenario, it does relate the idea that in either case, chewing seems to be our friend when it comes to less caloric intake.
Chewing More & Eating Slower Can Cut Your Calorie Intake
Based on the research examine here, when eating a mixed meal, smaller bites and longer chewing times may result in less hunger and eating less food overall. Chewing more not only allows for more absorption, but also seems to signal to the body that you have eaten enough, allowing your brain (which is slightly behind your stomach’s reaction to this) to register a feeling of fullness.
- Zijlstra N, de Wijk RA, Mars M, Stafleu A, de Graaf C. Effect of bite size and oral processing time of a semisolid food on satiation. Am J Clin Nutr. Aug 2009;90(2):269-275. ↩
- Li J, Zhang N, Hu L, et al. Improvement in chewing activity reduces energy intake in one meal and modulates plasma gut hormone concentrations in obese and lean young Chinese men. Am J Clin Nutr. Sep 2011;94(3):709-716. ↩
- Cassady BA, Hollis JH, Fulford AD, Considine RV, Mattes RD. Mastication of almonds: effects of lipid bioaccessibility, appetite, and hormone response. Am J Clin Nutr. Mar 2009;89(3):794-800. ↩
- Traoret CJ, Lokko P, Cruz AC, et al. Peanut digestion and energy balance. Int J Obes (Lond). Feb 2008;32(2):322-328 ↩