An excessive intake of dietary sugar has been demonstrated to have a negative impact on health and is associated with hypertension, obesity, dental caries and chronic diseases such as heart disease and type 2 diabetes.

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What makes food cravings different from general hunger is just how specific they are – an intense desire for a very particular food, which unfortunately tends to be something high in sugar (and fat).

So what prompts our urge for that midday sugary snack or late-night bowl of ice cream or tong sui (sweet soup)? Could it be our sugar cravings are actually telling us something?

It is a popular misconception that we crave foods containing nutrients we lack. Scientists used to suspect that if we craved a steak, we were low in iron, and if we craved chocolate, our bodies needed magnesium. However, recent research suggests that most cravings start in our brains, not our bodies.

Though it is hard to pinpoint the exact cause of sugar cravings, many scientists believe that it develops from a complex medley of biochemical processes and various hormonal and emotional factors. Sugary and fatty foods trigger the brain’s reward system (where we get that feeling of pleasure) in the same way that some drugs do. This stimulates a release of the feel-good neurotransmitter dopamine, which then causes our brains to signal to us to keep going back for more. So the more sugar we eat, the more we crave it, which can lead to loss of control and increased tolerance to sugar. Over time, these effects can be physically and psychologically taxing, leading to weight gain, dependence and even chronic diseases.

Other causes include:

Biochemical factors Each bite of food consumed is information for our gut microbiome – the bacteria that lives in our gut and which plays a key role in our digestion and immune system. When we eat sugar-laden foods, we are feeding the bacteria that thrive on sugar, which crowds out healthier bacteria and alters the important balance. These bacteria can then signal our brain to crave more sugar, clouding our judgment in making healthy food choices.

Blood sugar imbalance If a person’s body is ineffective in its management of glucose, this can also play a major role. Our blood glucose levels can fluctuate daily, but rapid and drastic fluctuations that fall outside acceptable levels can cause cravings, thirst and mood swings.

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Emotional factors When we are feeling stressed, upset or bored, we often turn to food for comfort. This is a natural and very common process. When we’re stressed, our body releases a high level of a stress hormone called cortisol. This leads to a craving for sugar, because the resulting burst of serotonin we get when we eat it is calming and relaxing.

Hypoglycaemia Low blood glucose, also known as hypoglycaemia, is a condition where blood sugar levels drop to below a certain acceptable level, often as a result of a lack of food consumption. This triggers symptoms such as food cravings (often sugar), headaches, tiredness and dizziness.

So how do we avoid – or beat – sugar cravings? Here are a few tips:

1. Quench your thirst with healthier alternatives

Drink either plain or carbonated water for hydration, instead of sugar-laden soft drinks. For those of you who love fruit juices, which are often packed with sugar, try adding a lemon or orange slice to a glass of sparkling water. This provides the flavour you enjoy, yet significantly reduces the sugar content.

2. Get enough rest

The more tired you are, the more your body craves sugar to give you an energy boost. Aim to get at least seven to eight hours of sleep each night and avoid using coffee as a pick-me-up, as caffeine can worsen sugar cravings. Reach for herbal, fruit teas or decaffeinated coffee instead.

3. Eat regularly, even when dieting

Going for too long without eating, or simply skipping meals, makes your blood sugar fall, which can result in food cravings and overeating – counterproductive for those who are trying to lose weight. Regular meals can help stabilise blood sugar levels so you won’t be hit by that mid-afternoon sugar slump. Being prepared also helps: always have a piece of fruit or a handful of nuts ready to tide you over until your next meal if cravings strike. Eating regularly can also help to increase the efficiency of your metabolism.

4. Replace sweets with fruit

If you still really want something sweet, try reaching for a piece of naturally sweet fruit instead. Fructose, the sugar found in fruits, is metabolised by our body differently than other types of sugar. These sweet treats provide an energy boost to our brain without the harmful effects of processed sugar, and with the added benefits of vitamins and fibre. Opt for low GI fruits (and foods) such as apples, cherries, and grapefruits for the fewest blood sugar spikes, as high GI foods cause fluctuations in blood glucose levels.

5. Get moving

Exercise has been shown to lower levels of stress hormones such as cortisol and release endorphins. Endorphins are chemicals in the body that help us feel good and are released into the bloodstream when we exercise, along with other “happy” hormones such as serotonin and dopamine. Our mood often affects what we eat and how much of it, so staying active will help to control cravings. Aim for 30 minutes of moderate-intensity physical activity five days a week for maximal health benefits.

Michelle Lau is a certified nutritionist and nutrition educator, and the founder of Nutrilicious (facebook.com/nutriliciousss), a Hong Kong-based nutrition consultancy company.