We all have a friend (or maybe we are that friend) who finishes his meal in about 10 seconds. It’s like they’re competing with each other to disguise their food faster than anyone else at the table.
No matter how hungry you may be, there is plenty of research out there to show the importance of chewing your food completely before swallowing it.
In fact, proper chewing could be key to achieving a chiseled jaw, leaner physique, and improved digestion. So let’s dive in.
The recipe for a weak jaw & double chin
A sculpted jaw is in great demand with bodybuilders, celebrities, and people who just want to be pretty. However, jaw strength is about more than just aesthetics. At a time when soft foods and liquid calories are the norm, the answer is clear: you need to prioritize solid foods and chew them well.
Food scientists engineered our foods to be softer, which requires less chewing. Think of the staples on a standard American diet: fries, cereal, bread, candy, etc. Even healthier foods like eggs don’t require a lot of chewing.
As we turn away from tougher foods like meat, fibrous vegetables, and tubers, our jaws get narrower, weaker, and softer. If we continue to trend in this direction, all of our future generations will have tiny jaws and double chins.
Chewing hard foods requires activating several muscles and bones of the face that would otherwise have gone limp. If you want a beautiful jaw, you have to chew.
This doesn’t mean taking 3-5 bites of a food and then swallowing it – it means chewing 30-50 times until you’ve broken the food into pieces small enough to swallow easily.
As you rush through your meal, you miss hundreds of extra “repetitions” to build muscles like the masseter, temporalis, medial pterygoid, and lateral pterygoid. These muscles are mainly made up of slow-twitch fibers, which means you want to accumulate a lot of volume.
You could even buy some hard gum to keep using these muscles. (Just don’t go overboard as chewing all day can cause jaw pain and even arthritis in the lower jaw.)
The first step in digestion
It chews. And when you do it right, your body produces the digestive enzymes it needs to break down the food you are preparing to swallow. It also triggers the production of hydrochloric acid and saliva to help guide food through the digestive tract.
Digestive enzymes are proteins that effectively signal the other systems in the body that you are ingesting food, and they start breaking down those food particles when they get into the stomach.
Different types of enzymes are responsible for breaking down different types of food: amylases help you digest carbohydrates, lipases make it easier to digest fats, and proteases are responsible for breaking down proteins. There are several other types of digestive enzymes, each of which is released in a different area of the body – the mouth, pancreas, stomach, and small intestine.
The longer we chew, the lighter the load on the esophagus, the easier it is for these different enzymes to do their job, creating less work for the stomach.
How chewing affects calorie intake
Several studies have shown an inverse relationship between chewing time and calorie intake during a given meal. One study compared the chewing habits of slim and obese people. At baseline, obese subjects consumed more food overall and relied on less chewing per gram of food consumed than lean subjects.
The researchers compared the differences in total calorie consumption during a meal and in subsequent ghrelin (a hormone that increases appetite) between subjects who chewed 15 times per bite and 40 times per bite.
The group that chewed 40 times ate fewer total calories (almost 12% fewer) and had a lower concentration of ghrelin.
Did you understand that? Those who chewed the most ate the least and felt more satisfied after eating than those who only chewed each bite 15 times (Li et al. 2011).
Have you ever eaten a large meal and still felt hungry afterwards? You may have eaten it too quickly.
The thermal effect of chewing
In addition to improving your feeling of fullness while you eat, chewing your meals fully can increase the thermal effects of the foods you eat. A study conducted in Japan concluded that eating quickly does indeed decrease the thermal effect of food (TEF). Think of this effect as the calories it takes to digest the food you eat.
So when you eat fast, your body doesn’t use as many calories to digest the food as when you eat slowly (Tomaya et al. 2015). Scientists estimate that 10 to 20% of your daily calorie consumption is caused by the thermal effects of food. So, chewing more thoroughly could have a significant long-term impact on metabolic rate.
Another study that tested young, healthy volunteers suggests that slow chewing increases energy expenditure per cycle compared to faster chewing. In this study, the chewing gum rate was compared to the calorie requirement.
The researchers compared 6-minute sessions of slow gum chewing (~ 60 cycles / min) and fast chewing (~ 120 cycles / min). Surprisingly, the slow chew group consumed significantly more calories than the fast chew group over the 6-minute window. Slower chewing can therefore have a positive effect on the daily metabolic rate (Paphangkorakit et al. 2014).
Rest and digest
As a personal trainer, I hear more and more customers complaining about digestive problems. From IBS to constipation to acid reflux, digestive problems can lead to physical ailments and other health complications. If you have gastrointestinal problems, increasing the chewing time can be a way of improving your digestion.
“Splanchnischer cycle” is a scientific term for the blood flow of the gastrointestinal tract, the liver, the spleen and the pancreas. One particular study found an inverse relationship between chewing time and splanchnic circulation.
Measurements of the diameters of two main arteries and the blood velocities in them showed that after meals with slower chewing rates, there was greater blood flow to these organs (Hamada et al. 2014). I’m sure you won’t be surprised to hear that areas of the body with greater blood flow tend to function more efficiently.
In an analysis of IBS patients, the researchers tried to examine various factors that contribute to lifestyle (regular meals, skipping breakfast, adequate chewing, consumption of spicy and fried foods, and tooth loss) and their effects on symptoms.
One of the most important findings was that “there was a significant positive relationship between lower chewing sufficiency (in people who did not chew all food) and the risk of IBS.” It appears that the chew rate and efficiency have a notable impact on the severity of symptoms in this population.
To optimize digestion, it is important that you chew your food efficiently.
Speed eating is not your friend
No matter how starved you may feel, don’t rush through your meal! Not only will you really enjoy the taste of your food, but you’ll also improve body composition, jaw strength, and digestion.
This small lifestyle intervention can have a variety of downstream health benefits. Take your time, chew your food thoroughly, and eat mindfully.
Related: The Important Muscles You Never Think About
Related: You are overfed but undernourished
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