If you want to look your best in the morning, it might be worth swapping the ultra-processed pastries and fruit juice for wholegrain toast and sugar-free tea.
Researchers in France found that people who ate a breakfast rich in refined carbohydrates were rated less attractive than those who started the day with healthier unrefined carbohydrates.
Scientists at the University of Montpellier believe the subtle shift in facial attractiveness may be driven by changes in blood sugar and insulin that can affect skin appearance and have longer-term effects on sex hormones.
“It’s surprising to consider, but our dietary choices can have rapid effects on our appearance,” says Dr Claire Berticat, an evolutionary biologist and first author of the study. “These physiological changes can subtly alter facial features, impacting how others perceive attractiveness.”
The researchers recruited 52 men and 52 women aged 20 to 30 and randomly assigned them to have a 500-calorie breakfast rich in either refined or unrefined carbohydrates. The refined carbohydrate breakfast included a French baguette made from industrially ground flour, jam, apple or orange juice, and tea or coffee with sugar available. The unrefined carbohydrate meal was ground wholemeal bread with butter and cheese, an orange or apple, and tea or coffee without sugar.
The scientists measured blood sugar levels of volunteers before and after they ate and then took headshots of the participants under controlled lighting conditions. The photos were then passed to groups of judges to estimate how old, how male or female, and how attractive the individuals looked.
Write in Plos Onethe researchers claimed that eating refined carbohydrates for breakfast reduced facial attractiveness for men and women, although the longer-term effects of eating such foods, obtained from questionnaires completed by the volunteers, were more complicated.
“The effect varies by gender and meal type, highlighting the complex relationship between diet and attractiveness,” Berticat said. “Our findings serve as a compelling reminder of the far-reaching impact of dietary choices, not only on health, but also on traits of particular social importance, such as facial attractiveness.”
Refined carbohydrates can produce spikes in blood sugar, which the body counters by releasing insulin. The reaction can cause sugar levels to drop too low, a condition called hypoglycemia, and can affect blood flow and skin appearance. In the study, only the refined carbohydrate breakfast caused hypoglycemia.
David Perrett, a professor of psychology at the University of St Andrews, who has studied facial cues to health, said it should come as no surprise that diet affects attractiveness. Fruits and vegetables improve attractiveness by increasing plant pigments called carotenoids in the skin, he said, while high-sugar diets can age the skin.
“The authors suggest that the refined carbohydrates may affect peripheral blood flow,” Perrett said. “Blood flow can change skin appearance very quickly. One can see the impact within seconds in the case of feeling sick when the blood drains from the skin. We found that most people look healthier and more attractive when their skin tone reflects a slight increase in oxygenated blood.”
Asked what advice she would give to people who want to look their best, Berticat said: “We know that refined carbohydrates have a negative impact on health and that’s reason enough to limit their consumption.”
