We all experience food cravings on a regular basis -- maybe even every day during that afternoon slump at work. Sometimes these cravings are easy to predict (especially for women during certain times of the month) while at other times it's totally random.
It's often said that food cravings mean that we're nutrient deficient in something, whether it's sodium, glucose or minerals like magnesium.
But is this really true? Are our bodies smart enough to tell our brain to crave a food which contains a particular nutrient, or is it just because these foods usually take the form of chocolate, chips and lollies?
To try and make sense of food cravings, and find out if they truly physiologically mean something, The Huffington Post Australia spoke to a few health experts.
"There are many different reasons we might get cravings," accredited practising dietitian Jemma O'Hanlon told HuffPost Australia. "It could be hormonal (think pregnancy and that time of the month for ladies), it could be a nutrient imbalance in our diet or it could also be related to environmental cues."
Dietitian and sports nutritionist Robbie Clark agrees, saying there's no one simple answer, but that factors like our emotions, mood, personal taste preferences and environment can all contribute to why we crave certain (usually unhealthy) foods.
"To say that we crave certain foods because that's what our body needs is a bit generic and naive," he told HuffPost Australia.
"It's important to understand that people's likes and dislikes, and the kinds of food they purchase and eat at any given moment, are impacted by a lot of variables. Some of those factors might still be unknown, but we're finding out more and more about what goes on in the body and the brain when we make these decisions."
Here are the possible explanations as to what our food cravings mean.
Think about the last time you saw an ad on TV for chocolate, dripping gloriously down the screen. Did you suddenly have an intense craving for it and possibly pop it into the trolley on your next food shop?
"It's amazing what advertising can do to our brains," O'Hanlon said. "Even scrolling through our Instagram feeds can make us hungrier.
"We can also crave foods simply because we're bored, or because of a habit we've created and the way we've programmed our brains to remind us at the same time each day."
Clark said we often underestimate the power of sight, sound and smell when it comes to foods we suddenly feel compelled to devour.
"It's well known that colour and appearance of foods can affect our taste perception," he said. "Environmental sights and sounds are also believed to influence your cravings, as well. Locations such as grocery stores, restaurants, retail stores and even your own home could play a role in what you crave."
We often like to believe, and justify our craving, by saying that wanting chocolate means we need magnesium or a mood booster thanks to its serotonin levels. Or, that we crave chips because our bodies need sodium. But is this true?
"Yes, seeking out or craving certain foods can sometimes be the sign of an imbalance within the body as a result of nutrient deficiencies," Clark explained.
"For example, when our blood glucose (sugar) levels drop because we haven't eaten in a while, we are likely to crave sugary foods to boost them back up. People with iron deficiency or anaemia may crave haem-based foods such as meats, and endurance athletes who train for many hours in a day and lose a lot of fluids through sweat are likely to crave salty foods in order to replace the electrolytes lost."
Nutritionist and celebrity chef, Zoe Bingley-Pullin, agrees, saying that nutrient deficiencies can play a large role in food cravings.
"Chocolate is rich in the mineral magnesium and can be a sign magnesium levels need a top up," she told HuffPost Australia. "Steak is rich in iron and zinc, and [craving it] can be a sign your body wants a serving up of the all important blood forming and immune supportive minerals."
However, O'Hanlon said there needs to be more research to back up this notion.
"We need more quality research before we can be confident this is the case," O'Hanlon said. "What we do know is enjoying a balanced diet, eating regular meals and choosing healthy portions will put us in the best position."
We've all experienced it: work is hectic and family life is a bit tense, and you feel a little low, stressed, overworked or anxious. Lo and behold, all you crave is chocolate, cake and doughnuts.
"Foods high in sugar and fat are linked with pleasure and release chemicals known as 'opioids' into the bloodstream. These bind to receptors in our brains, which release 'feel good' neurotransmitters. The more we eat of these types of foods, the more our brains can become programmed to crave these foods," O'Hanlon said.
"Junk food -- or the types of food we crave -- are normally fatty, sugar rich and have high carbohydrate content," Bingley-Pullin added. "Such foods are tied to release of serotonin and endorphins it explains why we crave them.
"Carbs is a common one. Carbs boost serotonin (our 'feel good' neurotransmitter) which causes us to seek them out. We often crave carbs when emotions are out of sorts. Refined sugar also, when eaten in excess, results in the release of endorphins which makes us feel good and crave more.
"These foods are often also filling and comforting when eaten. It's often certain times of the day (for example, the 3 p.m. slump) or after certain experiences (a stressful day) that cravings hit the hardest -- they are tied to emotions."
Women understand how much hormones can affect the way they eat throughout the month. According to Clark, there are other hormones that affect both men and women which can influence food cravings.
"Leptin resistance -- leptin is a hormone produced in your fat tissue. Its primary role is to stimulate your appetite," Clark said. "Regulation of this hormone is normal when your stomach and your brain are in sync. However, the problem starts when constant surges of leptin 'trick' your brain into feeling hungry, even when you're not."
Low levels of serotonin may also cause our bodies to crave certain foods.
"The neurotransmitter is produced mainly in the gut and is directly linked to our mood, appetite and digestion," Clark said.
"Eating carbohydrates and sugar increases the release of serotonin, making us feel fantastic (temporarily). So, when our levels of serotonin are low, our brain tells us that a sugary or carbohydrate-based snack will fix the problem."
Basically, food cravings are complex and can be due to a number of different reasons, some of which we don't fully understand. The important thing to know is that craving foods is completely natural, and that we should try our best to keep our cravings in check (that is, not eating a block of chocolate a day).
"We can break this cycle by replacing high sugar, high saturated fat foods with healthier alternatives that still give us that feel-good buzz without the unnecessary kilojoules," O'Hanlon said.
"For example, instead of having a chocolate bar as a 3pm pick me up, why not try having a tub of Greek yoghurt with some cacao powder stirred through, or cacao nibs sprinkled over the top."