How does inflation tie in with obesity?

Inflation is defined as the increase of the general price level, measured by a change in the Consumer Price Index (CPI). Obesity is commonly measured with the body mass index (BMI), a measurement which compares weight and height, defines people as overweight (pre-obese) when their BMI is between 25 kg/m2 and 30 kg/m2, and obese when it is greater than 30 kg/m2.

Both measures have increased over the last decades, which means that a statistical analysis is likely to show a positive correlation coefficient between the two time series. However, a positive correlation does not mean a causality: simply because both inflation rate and obesity have increased does not mean a that one has caused the other.

At least I am not aware of any credible theory that would establish such a causality. The comonality is more likely to be found in the etymology of the word: 'inflate' means to expand or to increase.