The benefits of chewing food will be part of a Newcastle-based study to examine links between diet, health and wellbeing.
The push to delve deeper into the issue comes amid widening concern about the links between processed food and chronic disease.
Another factor is that people increasingly want to eat more healthily to feel better.
The study, which has two phases, aims to enlist about 2000 people across Australia.
Hunter residents will be key to the second phase, which will involve about 300 people doing a range of free health tests.
This will include blood pressure and body composition [muscle and body fat] checks, along with blood and urine samples to check health status.
University of Newcastle Professor Clare Collins said people could join the study now.
"We'll also check risk factors for cardiovascular disease by looking at calcification of the big blood vessel, the aorta, which goes through your abdomen," Professor Collins said.
She said the research was important because people could "lower their risk of heart disease by eating better".
A stool sample will be collected with an at-home kit to test the microbiome of participants.
Researchers want to examine the microbiome to determine how diet relates to the "types of good and bad bugs" people have, and how this affects health and wellbeing.
The stool sample would also allow researchers to "evaluate and measure the presence of microplastics and their relationship with your diet".
"We will also measure chewing rate and gut transit by asking people to eat two breakfast muffins that contain blue food colouring, plus 25 grams of nuts," Professor Collins said.
"Then we'll ask them to send us an email and let us know when the blue food colouring appears in their stool.
"We'll then record when they first see the blue food colouring appear in their stool."
The gut transit study will show "how long it takes for food to travel the distance of your gut".
Many people who live busy, stressed lives tend to swallow food with less than optimal chewing, which is linked to poor digestion.
Increased chewing has been found to boost cognitive function.
"When you chew, more blood flows to your brain," Professor Collins said.
"Modern-day diets have pretty soft food," she said, citing hamburger buns as an example.
"We don't chew as much as we used to, when our food was much more unprocessed.
"We want to check whether that has any relationship with health and wellbeing."
Chewing had previously been found to benefit brain function, stress, anxiety, pain perception and hunger.
Professor Collins said people were often told "you need to take a pill or a supplement for this or that, but sometimes we forget how powerful food is".
"It's more than something that takes away feelings of hunger. It's a secret weapon," she said.
Most people 18 and over are eligible for the study, including people with heart disease or diabetes.
The study's first phase is an online survey, open to people across Australia, which takes up to an hour to complete on three occasions over 12 months.
The Hunter Medical Research Institute's food and nutrition research program is doing the study at the University of Newcastle.
It is funded by the National Health and Medical Research Council.
To participate, email PrecisionNutrition@newcastle.edu.au.
