Extended Data Figure 4: Relationship between activity inequality and obesity holds within countries of similar income.

Of the 46 countries included in Fig. 2a, we have 32 high-income (green) and 14 middle-income (orange) countries according to the current World Bank classification⁴⁰. We find that activity inequality is a strong predictor of obesity levels in both high-income countries and middle-income countries (LOESS fit). Although in middle-income countries, iPhone users might belong to the wealthiest in the population, in high-income countries iPhones are used by a larger proportion of the population. That we find a strong relationship between activity inequality and obesity in both groups of countries suggests that our findings are robust to differences in wealth in our sample.