According to recent research, those who order grande lattes or super-size their food portions don't necessarily have bigger appetites, but could be trying to improve their social status.
Researchers from the HEC Paris business school carried out tests to establish whether bigger portion sizes are associated with high social status.
The majority of participants assumed that people who ordered an extra large food portion were of a higher social status than someone who ordered a small size.
The study found that ordering large was common among the less wealthy and could partly explain the obesity rates being higher in lower-earning communities.
"An ongoing trend in food consumption is consumers' tendency to eat more and more," says researcher David Dubois.
"Even more worrisome, the increase in food consumption is particularly prevalent among vulnerable populations such as lower socio-economic status consumers."
Researchers hope that these findings, published in the Journal of Consumer Research will help tackle the obesity levels among the lower classes.
"Understanding and monitoring the size-to-status relationship of food options within an assortment is an important tool at the disposal of policy makers to effectively fight against over-consumption," professor Dubois added.