Laura Castells Navarro is a British Science Association Media Fellow, funded by University of Bradford


If a few years ago it was the trans fats that were seen as a leading cause of poor health, now is the time for sugar to be demonised. Sugar and a wide variety of issues around it have been a recurrent topic of recent news, usually for all the wrong reasons. At the British Science Festival, an interdisciplinary trio of presenters formed by Dr Judy Anne Swift, Professor of Behavioural Nutrition at the University of Nottingham, Anthony Warner, chef and science writer, and Dr Duane Mellor, Lecturer in Human Nutrition and dietitian at the University of Coventry argued against this narrative, and advocated that sugar has also its place in our society.

The controversy around sugar is longstanding, and Dr Mellor started by pointing out that recommendations to reduce the amount of added sugar are not new. In fact, the consumption of sugar is declining in our society. As far back as in 1972, it was poised as one of the great dangers to public health, but in  2015 that the campaign  against sugar was reignited by a report from the World Health Organisation nutrition committee about the impact of sugar on diet. In the same year, the guidelines issued by Public Health England put anything containing non-naturally occurring sugars (such as cereals, yogurts, biscuits, confectionary, sweet spreads among others), as the target of a governmental policy aimed at reducing the amount of sugar consumed by children and the society in general. These guidelines had been famously lobbied for by the celebrity chef James Oliver and culminated in the establishment of a soft drink industry levy, widely known as the “sugar tax” in 2017.  

But, what is sugar? Dr Mellor explained that sugar is not one molecule, and while the most common form of it is glucose (so important for the correct functioning of our body that we can even synthetize it) fructose and lactose, the sugars in fruit and milk are also widely available. Recently, other types of sugar like  honey,  agave syrup, coconut and raw sugar have come up as the “healthy” options to sugar. However, Dr Mellor pointed out that while the characteristics of these sugars might be different, for example some might be absorbed or burnt in a slower or faster manner, their effect on our system is exactly the same because, “at the end, sugar is just sugar”.

And why do we like it so much? Chef Anthony Warner explored the importance of sugar as a multipurpose versatile ingredient. He noted that while the main reason to add sugar is to improve the sweetness of a recipe, the physicochemical characteristics of sugar also help to improve the flavour palate of savoury dishes, for example by counterbalancing the acidity of some ingredients (such as tomato). The caramelisation of sugar in baking improves the appearance of cakes by promoting the aeriation of the batter and adding extra layers of flavour. And finally, for industry, sugar is important in the preservation of food and increasing the products’ shelf-life. These characteristics mean that sugar is notoriously complicated to successfully replace in cooking and industrial food production.

Dr Swift referred to some studies that suggest we are conditioned to like sugar (as well as fats) because it packs high amounts of energy in relatively small quantities. However some people question whether sugar is a nutrient per se and therefore whether it is  needed in our diet. Part of this demonization and attempt to remove sugar from our diet is related to the increase in the prevalence of obesity in our society. However obesity is a multifactorial condition and, while in some individuals the reduction of sugar could help in managing the condition, the reality is that by only removing sugar from the diet, the obesity epidemic will not disappear. Furthermore, it is very common to replace the sugar for other ingredients, which as, previously indicated, have the same effect as sugar, or by increasing the proportion of fat or carbohydrates content and thus actually increasing the calorie density of the “healthy” option.

So, according to the team of presenters, sugar is not good or bad but should be examined with a more holistic view of “nourishment”. They considered that the focus on only one ingredient was not only physically unhealthy but could also impact on the mental wellbeing, since the stigmatisation of sugar can also lead to guilt-related mental issues. Thus, they concluded, instead of focusing too much in a single ingredient or in controlling what is being eaten, the focus should be shifted towards the impact of food (including sugar) in would general wellbeing instead; in the experience of eating, of sharing food and the enjoyment brought from the company the food is shared with. At the end of the day, Dr. Mellor concluded “food is nourishment, it is physical, it is mental and is social health; food is not only the nutrients that come with it”.