People are not jumping to help you are they.

Farm size is growing because of economics of crop production, independent of the crop being grown and is a worldwide phenomenon. It is driven by each country’s desire for “cheap” food and the need for labor to man the factories. The process can be reversed by government actions but no country has reversed the process successfully (think Zimbabwe, Cuba, etc.).

Corn happens to be the crop that grows the best in the Midwest. >60% of the carbon energy humans in the US eat comes from corn. Corn is a very efficient plant in converting sunlight into energy that can be directly utilized by humans. The cost (dollars per 1000 kcal, the environmental cost of increasing the number of acres in crop production – both in the US and worldwide, etc.) of switching to something other than corn is staggering.

High fructose sweeteners bypass a hormonal control system that regulates calorie consumption. That is bad. Government policy could reverse this use overnight it there was a mandate (and the will).

Corn has been known to be an “incomplete” food for >10k years. Its protein lacks sufficient lysine and tryptophan for “human” requirements, among other nutrient limitations. That is why early Americans domesticate corn, beans and squash (i.e., the three sisters) – and grew them together. Genetic engineering can change that but the use of that approach is still generally prohibited by government’s policies.

Switching to a less efficient production system means that the world’s population must be significantly reduced or that much more land must be brought into cultivation. Much, much more actually because the best land is already being cultivated.

Your audience will be young, educated and relatively wealthy.  You will need to point out repeatedly that millions people in the world are starving without enough calories and/or protein and that 10’s of thousands of those die of their malnutrition every day. Any change in reverberates across international borders.