In a new study published in PLOS ONE, researchers have unveiled intriguing findings that link the consumption of refined carbohydrates — such as sugary snacks and highly processed foods — with changes in facial attractiveness. The study found that individuals who consumed a high glycemic load breakfast were rated as less attractive than those who consumed a low glycemic load meal.
The transition to a diet rich in refined carbohydrates — foods depleted of their natural fiber and overloaded with added sugars — has not only contributed to the prevalence of various metabolic diseases but also sparked curiosity about its potential impact on human physical traits, including facial attractiveness. Given the role of attractiveness in social interactions, mating preferences, and even professional success, understanding its correlation with diet is of significant interest.
“We were initially intrigued by the profound impact of our food choices on our physiology,” said study author Claire Berticat of the Institute of Evolutionary Science of Montpellier. “While the effects of refined carbohydrates on certain hormones are well-documented, it is less known that sex hormones can also be affected. Certain traits, such as facial attractiveness, are influenced by sex hormones. Thus the possibility of uncovering a previously unexplored connection between refined carbohydrate consumption and attractiveness was highly appealing.”
The research team recruited a total of 104 participants, evenly split between males and females, aged 20 to 30 years. The recruitment process involved online calls through university networks and social media platforms, targeting a demographic likely to provide a homogeneous sample in terms of age and health status.
Participants were asked to attend study sessions early in the morning on an empty stomach. Upon arrival, they were randomly assigned to consume one of two types of isocaloric breakfasts: one high in refined carbohydrates and the other low. Approximately two hours after consuming their assigned breakfast, participants were photographed under standardized conditions to ensure consistency in lighting, background, and positioning.
The attractiveness of participants was assessed by a separate group of raters (110 men and 142 women), who were recruited in public places and carefully selected to minimize cultural bias. Raters evaluated the facial photographs, making judgments on perceived age, masculinity/femininity, and overall attractiveness. This evaluation process was designed to objectively measure the impact of dietary factors on how faces are perceived by others.
To evaluate chronic dietary habits, participants completed detailed dietary questionnaires concerning their consumption during breakfast, afternoon snacks, and between-meal snacks on the day before the study. This information was used to calculate the glycemic load and energy intake for these meals, providing a comprehensive picture of participants’ usual refined carbohydrate consumption.
Additional data were collected on various demographic, lifestyle, and health-related factors, including physical activity, smoking status, and for women, the use of hormonal contraceptives.
Participants who consumed a high-glycemic breakfast (rich in refined carbohydrates) were found to be less attractive than those who consumed a low-glycemic breakfast. This effect was observed for both male and female participants. The researchers proposed that this could be related to the physiological effects of hypoglycemia (low blood sugar), such as changes in skin blood flow and complexion, which occur following the consumption of high-glycemic foods.
When examining chronic consumption of refined carbohydrates through glycemic load measures, the researchers found that a higher energy intake at breakfast was associated with increased attractiveness for both men and women, suggesting that foods high in fats and proteins, which do not lead to rapid glycemic responses, might contribute positively to perceived attractiveness.
Conversely, chronic consumption of refined carbohydrates, particularly during afternoon snacks and between-meal snacks, was generally linked to decreased attractiveness. This effect was thought to be mediated by the long-term physiological consequences of sustained high glycemic load, such as hyperinsulinemia, which could influence sex hormone levels and subsequently affect secondary sexual traits.
“We have found that consumption of refined carbohydrates, whether immediate or chronic, affects facial attractiveness,” Berticat said.
However, the effects of refined carbohydrate consumption on attractiveness varied depending on the specific meal and the gender of the participants. For example, while high energy intake at breakfast increased attractiveness across both genders, the glycemic load of afternoon snacks had opposite effects for men and women. Men with a higher glycemic load during their afternoon snack were perceived as more attractive, whereas for women, a lower glycemic load in this meal was associated with increased attractiveness.
“We found that the results differed, at least for men, according to the different meals of the day (breakfast, afternoon snack and between-meal snack),” Berticat explained. “The varying impact of different meals on attractiveness highlights the complexity of dietary influences on physiology. The fact that the ecophysiology of food intake varies throughout the day (physiology, needs, environment, cultural habits etc.) could be an interesting explanation to explore further.”
Importantly, the study controlled for a range of potential confounders, including physical activity, BMI, smoking status, and, for women, hormonal contraceptive use. These variables significantly influenced attractiveness ratings, underscoring the multifaceted nature of attractiveness and the importance of considering a broad spectrum of factors when investigating the effects of diet on physical appearance.
But the study, like all research, includes some limitations, such as not controlling for factors like skin color, menstrual cycle, sleep quality, and overall diet quality. The authors call for further research to explore these aspects and to understand the broader social implications of diet.
“Our findings serve as a compelling reminder of the far-reaching impact of dietary choices not only on health but also on traits having particular social importance such as facial attractiveness,” Berticat said. “Investigating how refined carbohydrate consumption may influence other traits influenced by sexual hormones could provide valuable insights into the complex interplay between diet, biology, and social behavior.”
The study, “Chronic and immediate refined carbohydrate consumption and facial attractiveness,” was authored by Amandine Visine, Valerie Durand, Leonard Guillou, Michel Raymond, and Claire Berticat.
