Spanish population trends in Internet searches for information on different diets

To use Google Trends to explore the trends of interest of the Spanish population regarding information related to different types of diets, focused on those that are popular and with evidence-based studies, over the last 10years.

The search trends referred to the terms «Mediterranean diet», «ketogenic diet», «low fat diet», «intermittent fasting» and «vegan diet» were analyzed. The relative search volumes (RSV) of the terms were compared. The direction of the trend was studied using the Spearman's correlation coefficient (SC).

«Mediterranean diet» was the most widely searched term, with a median RSV of 16 (interquartile range [IQR] 6; range 8-100), though it exhibited a decreasing chronological trend (SC=-0.216). It was followed by «ketogenic diet», with an RSV of 8 (IQR 9; range 1-57); «vegan diet», with an RSV of 4 (IQR 5; range 0-16); «intermittent fasting», with an RSV of 2 (IQR 5; range 0-27), and «low fat diet», with an RSV of 1.16 (IQR 0; range 0-2). The term with the best correlation over time was «intermittent fasting» (SC=0.96), followed by «ketogenic diet» (SC=0.91) and «vegan diet» (SC=0.85).

In Spain, the interest of the population in information about the Mediterranean diet is greater than for other diets. However, in recent years there has been a progressive increase in interest (measured as RSV) in other diets such as the ketogenic diet, vegan diet or intermittent fasting, and there has been a decrease in interest in the Mediterranean diet. The low fat diet does not generate interest in the Spanish population.