Global and local diet popularity rankings, their secular trends and seasonal variation in Google Trends data
Mikołaj Kamińsk Nutrition Available online 12 February 2020,
Background
he Internet has become the main source of health-related information including nutrition We aimed to rank the most popular diets among Google users globally and locally as well as secular and seasonal trends in the years 2004-2019.
Methods
We used Google Trends (GT) to identify and analyze course over time and regional interest of (n = 47) topics related to diets. We analyzed secular trends using the Seasonal Mann-Kendall test and seasonal variation using time series decomposition. The topic "Mediterranean diet" (MD) was used as a benchmark. We calculated the interest of all topics in proportion to the Relative Search Volume (RSV) of MD.
Results
Globally, Google users were particularly interested in "Veganism" (19.54 [times higher than MD]), "Vegetarianism" (15.09), and "Gluten-free diet" (11.11). “Veganism" was the most frequently searched in 23 countries followed by "Vegetarianism" (14), "Ketogenic diet" (7), and "Low-carbohydrate" diet (7). Whereas an increase of RSV over time was observed for 23 diets, a decrease was noted for 20. The most dynamic increase was found for "FODMAP" (6.12 RSV/year), "Gluten-free diet" (5.95 RSV/year), and "Raw veganism" (5.72 RSV/year). Sharp declines concerned "Negative-calorie food" (-4.34 RSV/year), "Macrobiotic diet" (-3.89 RSV/year), and "Cabbage soup diet" (-3.50 RSV/year).
The interest in most diets falls in December, but peaks in January.
Conclusion
Veganism, vegetarianism, and gluten-free diet attract the largest public interest globally. Both secular trends and seasonal variation shape the ever-changing landscape of diet popularity. Google Trends holds promise as a valuable tool in local and international nutrition research.
