Daily sugar consumption has steadily risen over the last few centuries (1,3). Sugar is used for many purposes, such as making foods and drinks taste sweeter, look better and last longer (1). It has been well documented that the increased levels of sugar in the food we eat are contributing (at least in part) to a variety of health concerns and conditions (1). This article will explore all things sugar, how we get addicted to eating it and what the results of its overconsumption are. It will then recommend ways to reduce and control how much is consumed daily and outline safe and healthy limits to stay within.
What is sugar?
Sugar is a type of carbohydrate that is naturally found in many foods or is added into foods by manufacturers (1). Every carbohydrate we eat is broken down into a simpler form called glucose, which is used to power crucial functions in our bodies (1). Simple carbohydrates like glucose, fructose, sucrose and lactose are found in many of the foods we eat (1). They are classified as simple because their chemical structure only consists of one to two molecules bonded together (1,3). There are other, more complex carbohydrates, such as those found in wholegrains, that are made up of multiple molecules (1,3). Due to having less bonded molecules, simple carbohydrates are digested quicker and spike blood glucose levels faster and higher when compared to complex carbohydrates (1,3).
Sugar is simply an energy source (1,3). Furthermore, there is no difference between additive sugar and naturally occurring sources (1). Like all things, problems start to occur when it is overused/consumed, or when whole foods are replaced with high sugar/low nutrient dense foods on a regular basis (1,2,3,4).
How we get addicted to it
When we eat, the hormone dopamine (among other hormones) is released into our system (1). Dopamine is known as the reward hormone and helps to reinforce behaviours that give us pleasure (1). Also, eating food has been shown to reduce stress levels (1). Foods with a higher sugar content promote a bigger release of dopamine and stress relieving hormones (1). These effects can cause a cue association to form, i.e. I want to feel good and eating a sugary snack helps me to do that (1). Over time, consistently eating high sugar foods strengthens the pathways in the brain that are associated with pleasure and stress relief (1). This can build into a powerful habit loop, which hijacks the reward system of the brain, and increases the drive to eat more sugary, less nutritional food (1).
The effects of overconsumption
Over consuming sugar effects everything from physical and mental health through to the very structure of the brain (1,2,3). Foods and drinks that are high in sugar content tend to be low in other nutrients (1,3,4). Regular consumption of less nutrient dense foods can contribute to a vitamin and mineral deficiency, which can negatively affect normal functions of the body (1,3). Also, high amounts of sugar can contribute to tooth decay, as bacteria that feed off sugar produce acid that permanently damage our teeth (3).
Moving past the mouth, high levels of sugar have been shown to increase the drive to eat (1). This is because sugar reduces the amount of the hormone leptin in the bloodstream and increases levels of the hormone ghrelin (1). Leptin helps us to feel full and satisfied and ghrelin spikes hunger (1). This can lead to excessive food consumption where there is more sugar in the bloodstream than can stored in the body (1). The excess sugar is converted and then stored as fat by the liver (1). If this happens on a consistent and long-term basis, it can lead to the development of obesity (1). It is estimated that as much as 39% of the adult population of the world is classified as obese, with the total number rising every year (1).
Obesity and constantly high levels of circulating sugar can cause widespread inflammation in the body and can contribute to the development of type two diabetes (1). This then increases the risk of other diseases (such as cardiovascular) developing (1).
As mentioned above, habits can be formed around eating certain foods that lead to higher levels of pleasure and stress relief (1). Consistently eating high levels of sugar can also lead to changes in the structure of the brain (1). Jacques et al. found that a high intake can reduce the production of new brain cells in areas such as the hippocampus and change the way they function. This is turn can negatively impact memory and cognitive ability, behavioural patterns, and mood (1). This coupled with obesity and other diseases have also been shown to increase rates of depression and anxiety (1).
What is a healthy daily limit of sugar to aim for and how do we go about achieving that?
As recommended by The World Health Organisation, sugar should make up no more than 10 percent (optimally five percent) of our total daily calorie intake, which equates to approximately 25 to 50g for an adult (3). Keep in mind one can of coke contains 30 to 39 grams of sugar (5), so being aware of what you are putting into your body is the first step towards limiting sugar consumption (4).
Alongside being aware of how much sugar you are putting into your body, there are other methods to help control its intake. As found by Palmedo et al., limiting where high sugar drinks and foods can be eaten can potentially be a good way to reduce overall intake. Having readily available substitutes and different meal options that are lower in sugar and higher in nutritional value can also be helpful (4). Fruit and vegetables do contain sugar, but at a much lower level compared to snacks and soft drinks (1,3). They also contain key vitamins, minerals and fibre that promote optimal health and function (1,3).
As mentioned by Palmedo et al. change can be difficult, particularly if a behaviour has been repeated for a long time. It is important to learn as much as possible about the negative health effects of high sugar consumption, as it can help to drive change (4). Also, seeking support of friends, family, and/or a community can help with accountability (4). Finally, getting professional support can help to address behaviours and any underlying conditions that may be contributing to excess sugar consumption (4). From there, action plans can be put in place that encourage better food choices and better health overall.
Sugar is not bad, but overconsuming it is (1,2,3,4). Just remember to eat it in safe amounts and from nutritional sources of food where you can.
1. Jacques A, Chaaya N, Beecher K, Ali SA, Belmer A, Bartlett S. The impact of sugar consumption on stress driven, emotional and addictive behaviors. Neuroscience & Biobehavioral Reviews. 2019;103:178-99.
2. Rodda SN, Booth N, Brittain M, McKean J, Thornley S. I was truly addicted to sugar: A consumer-focused classification system of behaviour change strategies for sugar reduction. Appetite. 2020 Jan 1;144:104456. doi: 10.1016/j.appet.2019.104456. Epub 2019 Sep 13. PMID: 31525418.
3. Sugar [Internet]. [Place unkown: Health Direct]; [Date unknown] [updated 2021 July, cited 2023 May 5]. Available from https://www.healthdirect.gov.au/sugar#:~:text=The%20World%20Health%20Organization%20%28WHO%29%20recommends%3A%201%20Adults,the%20nutrition%20panel%20on%20the%20food%20label.%20
4. Palmedo PC, Gordon LM. How to be SSB-free: Assessing the attitudes and readiness for a sugar sweetened beverage-free healthcare center in the Bronx, NY. PLOS ONE. 2019;14(5):e0215127.
5. Lehman, S. How Much Sugar Is In a Can of Soda? [Internet]. [Place unknown], Verywell Fit; date unknown [updated 2021 January 14; cited 2023 May 5]. Available from https://www.verywellfit.com/guess-how-much-sugar-is-in-a-can-of-soda-2506919#:~:text=When%20consumed%20in%20excess%2C%20added%20sugars%20can%20contribute,recommended%20daily%20intake%20for%20a%20healthy%20diet.%201