If you've ever been on a diet for a few months, you might have noticed that over time you don't need as much food to make you full. On the other side, if you've been eating larger portions more recently, you may have noticed your appetite is bigger and you need more food to feel full.
But does the size of our stomach really change depending on how much (and what) we eat? Or are there other factors at play here?
"Your stomach gets a workout each time you have a meal, stretching and contracting repeatedly throughout the day," dietitian Kaitlyn Bruschi told The Huffington Post Australia.
"If we frequently eat large meals then our stomach will eventually starts to lose its tone, meaning it takes more food to fill us up.
"This measure is known as our stomach capacity. Think of it like a balloon -- the first time you try to blow it up you have to use a big breath and lots of force. Letting the air out and blowing it up again, it will be easier to inflate. It's not the size of the balloon that is changing, but its ability to stretch and hold a larger volume. Same with your stomach."
While the actual size of our stomachs does not change, research shows it's the capacity which alters depending on our dietary habits. This doesn't necessarily mean, however, that it's only larger or overweight people who have a larger stomach capacity.
"By regularly eating either small or large meals we can alter the anatomy of our stomach," Bruschi said.
"What's interesting is that we see this increased stomach capacity in healthy weight individuals with bulimia who report regular binge eating, which suggests it is the size of our meals that dictate stomach capacity rather than size of the individual."
One of the best strategies to reduce stomach capacity and hunger signals is to practise mindfulness -- becoming more in tune with what our body is telling us about our hunger levels.
Another factor at play when it comes to our stomach capacity are our 'hunger hormones' which tell us when we're hungry and full. Interestingly, the larger our stomach capacity, the longer it takes for the 'full' hormone to register in our brain.
"Nerve receptors in the stomach wall send signals to the brain once it has been stretched beyond a certain point -- suggested to be about 70 percent of your stomach capacity," Bruschi told HuffPost Austalia. "It goes to follow that individuals with a larger stomach capacity will need more food before the stomach reaches this point.
"As we digest our food and our stomach shrinks back to normal size, it starts to produce a hormone called ghrelin. This hormone tells our brain that we are getting hungry again."
Although we cannot alter the actual size of our stomachs (without restrictive stomach surgery such as gastric imbrication), Bruschi said it is possible to reduce the capacity of our stomach through mindful eating and a healthy diet.
"One of the best strategies to reduce stomach capacity and hunger signals is to practise mindfulness -- becoming more in tune with what our body is telling us about our hunger levels," Bruschi said.
"To become a mindful eater you need to eat like a food critic. It takes about 20 minutes for the stretch signal to get from our stomach to our brain to stop us eating, so if we gulp down our meals quickly we are more likely to overeat.
"Remove distractions and eat slowly, savouring your food. Appreciate the smell, texture and appearance, rather than just the taste."
Focusing on smaller, yet more nutrient-rich, portions can also help tone our stomach from the inside.
"Just do this gradually, or you may get some serious hunger pangs," Bruschi explained.
"As always, make sure you are also choosing nutrient-rich foods -- fruit, vegetables, lean protein, low fat dairy and whole grain carbs. This helps you reach your stomach's capacity while consuming less kilojoules compared to a similar size meal made up of fats, simple sugars and processed foods.
"Veggies are great for this process as they can fill us up without adding excessive energy to your day."