N is 15, not 299.

This is comparing one measure for each of the 15 countries against three other measures (cabinet minister's average obesity Vs. Transparency International Corruption Perceptions Index, World Bank worldwide governance indicator Control of Corruption, and Index of Public Integrity).

The 299 is the combined number of cabinet ministers whose weight were averaged, which is a single measure per location, not the actual subject of the statistical question (which is a country, not an individual cabinet minister).

It also isn't in a peer reviewed journal at all.