I'd question that. Poor Americans maybe. But the average american has relatively average work hours[1], shops at large grocery stores or supercenters[2], and has among the highest median income in the world(adjusted for PPP)[3]
1. https://en.wikipedia.org/wiki/Working_time#OECD_ranking
2. https://www.ers.usda.gov/amber-waves/2015/august/most-us-hou...
3. https://en.wikipedia.org/wiki/Median_income#Gross_median_hou...