They give the recipients the ability to get unhealthy food at the cost of the US taxpayer. This causes multiple issues that affect all taxpaying Americans in addition to the cost of the food subsidy, including adding to the cost of providing healthcare (pushing up premiums, etc).

It seems counterintuitive that having unhealthy food increases healthcare costs over not having enough food. How does that work? Is it because they don't live long enough to accumulate medical expenses? That still doesn't sound like a net win for taxpayers.