By setting up an equation where you add in any possible negatives and don't consider any positives you are by definition going to get a result like this.
For instance, they say how much we spend because cheap food makes obesity possible, but think of the number of people that would be cutting corners on their housing/health if their food budget increased another $300 a month. They even list a negative cost of people having food insecurity but that would only get drastically worse with more limited cheap options. They say that the current food regime is bad for workers because there is underpayment of wages and jobs that lack benefits - but are these workers going to be better off if the price of McDonald's goes up 2x, people eat out less, and the jobs get eliminated completely.
I think there are a lot of obvious policy things we could do to improve our health (shifting corn subsidies to other things, for instance) but I don't get the point of studies like this.