GENES inherited from a person's parents can change the way they interact with food, such as their hunger, what they like to eat and whether they gain or lose weight.
As an identical twin with nine siblings, University of Newcastle molecular nutritionist Dr Emma Beckett has always been interested in DNA, even before she knew what it was. She is one of nine UON scientists who will share their expertise with primary schoolers through Dig Deep with a Mad Scientist sessions on Saturday, as part of UON's Science in Practice virtual event.
"How we taste food and how we smell food, we've all got our own unique combination of genes for that, so for some people vegetables and salad are very bitter and unpalatable whereas for others if you've got less sensitive versions of those receptors, salads and veggies can taste buttery and much more palatable," she said.
"But there's also differences in how we metabolise food, so how readily we can extract the energy from food, so we could all eat the same thing and some of us would gain weight and some of us would lose weight and some of us would stay the same weight.
"There's differences in how our brains detect whether or not we're hungry or full, which comes from differences in genes both in our brains and in our gut, detecting what is there. Then it gets even more complicated because it's not just our genes we need to worry about, it's the genes of the microbes that live in our guts as well.
"It's starting to look like they are part of the signalling chain that start to tell us whether we're hungry or full and how much we want to eat and what exactly we do want to eat, so every step of desiring and processing and using the energy and nutrients from food, we all have our own versions of that."
Dr Beckett said this can help explain why some diets work for some people and not others, although she said learned habits and the environment could also influence a person's relationship with food.
"You can train your body or retrain your body from the genetics, but the genetics is your jumping off point or the baseline you start at," she said. "Some things are harder for some people. People talk about willpower and if you want to lose weight just eat less, why do you keep eating food, but we all have a different set point for how hungry we feel and for some people they're just not going to feel full on the normal or correct amount of food so it makes it a lot harder."
She said a lot of dietary advice was based on experience and trial and error, but if it was personalised based on some key genes this would take out a lot of trial and error, failure and guilt.
"If you look at weight genes for example, the genetics you have related to weight loss or weight gain can explain seven or more kilograms of your body weight."
She said current recommendations were broad and general, but tailoring them more could help "level the playing field in the way our diet links to our health", not only in relation to weight, but also diseases linked to food.
Experimental psychologist Associate Professor Darren Burke will discuss how the structure of faces - not just facial expressions or movements - send signals. He said face shapes convey accurate information about age, sex, height, health and even things like fertility, even if people aren't consciously aware they are detecting these details in other's faces.
National Science Week concludes on Sunday. UON's event also includes a live show, workshops and three ocean-themed webinars.
Details: newcastle.edu.au/faculty/science/community-engagement/science-in-practice
