There are many different factors that affect a country's wheat consumption. Perhaps most important is culture. But this is difficult to measure. A possible proxy for this could be looking at how many bakeries exist in a certain area.
For this data visualisation I downloaded a list of bakeries from OpenStreetMap using Overpass Turbo, and used d3-hexbin plugin together with leaflet to map the density of bakeries in two capital cities - London and Paris. Adapted from Tom Nightingale's hexbin example using leaflet and d3js.