When it comes to food and eating, we all have different approaches. There are some of us who see food just as delicious food, while others see it in terms of nutrition or even as energy (calories).
While it's important not to get too caught up in the amount of calories in food (because not all calories are created equal), knowing about empty calories is a helpful way to stay on track and keep your weight in check.
To understand more about empty calories and which foods and drinks they are found in, HuffPost Australia spoke to two health experts.
What is a calorie?
"A calorie is a unit of energy. It is the amount of energy or heat that is required to raise the temperature of one gram of water by one degree Celsius," Rebecca Gawthorne, accredited practising dietitian and nutritionist, told HuffPost Australia. "One calorie is equal to 4.18 kilojoules.
"In a food and nutrition context, a calorie is the unit of food energy. When people talk about the calories in food, they are referring to how much energy that food provides your body when you eat or drink it."
What is an empty calorie?
"Empty calories refer to foods that are high in calories (that is, they are 'energy-dense') but are also 'nutrient-poor', meaning they are very low in essential nutrients and have little or no nutritional value," Gawthorne said.
"These are foods that are often heavily processed with many additives and we don't require them in our diets -- we can live without them."
As nutritionist Steph Lowe of The Natural Nutritionist explained, "an empty calorie refers to nutrient-poor foods and drinks that are usually full of added sugars and poor-quality fats".
What are empty calorie foods?
Empty calorie foods and drinks include: soft drinks, alcohol, energy drinks, cordial, some white breads, biscuits, sweets, pastries, ice cream, condiments, fatty processed meats and many deep-fried takeaway foods.
Do empty calories make you gain weight?
The short answer: yes.
"There is no health benefit to consuming foods that contain empty calories and they can actually have a negative impact on our health, leading to weight gain and chronic diseases, so it's best to limit or avoid empty calories," Gawthorne said.
"The Australian Guide to Healthy Eating recommends limiting discretionary foods, which would include empty calories, to only 'sometimes' and in small amounts. There is no specific calorie amount [to stay within] but it's best not to consume empty calories on a daily basis."
But why exactly do these energy-dense, nutrient-poor foods cause weight gain? Lowe explained this is primarily due to the way refined sugars and poor-quality fats affect our body's processes.
"Refined sugar spikes the fat storage hormone insulin, and poor-quality fats impair mitochondrial function and contribute to inflammatory weight gain," Lowe told HuffPost Australia.
What's the opposite of empty calorie foods?
The foods we should replace empty calorie foods with include healthy foods like vegetables, fruits, whole grains, lean protein and healthy fats such as avocado, nuts and seeds.
"Foods that are opposite to empty calories are those that are energy-dense (that is, they contain calories -- but remember calories aren't 'bad' or 'unhealthy' when accompanied by nutrients we need to live) and are high in essential nutrients," Gawthorne said.
"For example, foods like salmon, nuts and avocado contain nutrients and calories but are very healthy for us."
Now, with all this talk of calories, it's important to mention that counting calories isn't the best way to manage or lose weight. While it's good to know about empty calories, both Gawthorne and Lowe recommend focusing on real, whole foods rather than their caloric value.
"I believe it's more important to focus on the health and nutritional value of food instead of calories," Gawthorne said.
"It's good to be aware of calories in foods, especially when it comes to empty calories. However, I don't believe counting calories is a healthy way to lose weight. Counting calories can become an obsessive habit and take the focus off health and doesn't always lead to weight loss or improvements in health.
"When people count calories, they also often avoid foods that are nutrient dense and higher in calories (like those mentioned before -- fatty fish, nuts and so on) and replace them with lower calorie foods that have minimal nutritional benefit."
Further, Lowe highlighted that to describe weight loss as 'energy in versus energy out' isn't telling the whole story. For example, 150 calories of chocolate will not be processed in the body the same way as 150 calories of fruit.
"One of the biggest myths is what we refer to here at The Natural Nutritionist as 'The Calorie Fallacy'. Physiology is not math or physics for that matter," Lowe said. "It's about eating real food."