The argument that excluding "unhealthy" items would make participants healthier, Alston tells ABC News, "is not a lay-down hand at all." Why not? First, he says, there's nothing to prevent participants from saving up their cash for ice cream. "You can restrict how people spend their stamps but not change their total consumption." Second, no matter how the program's standards might be tweaked, manufacturers, he says, will tweak their products to try to get around the prohibition.
"They will re-engineer the food," he says. The revised products will be different; that doesn't necessarily mean they'll be any more nutritious.
Although changing program rules to promote healthier eating could indeed be expected to reduce participants' obesity, Alston and his co-authors say that the effect on food prices overall might be to make "healthy" food relatively more expensive for non-participant consumers (and "unhealthy" food relatively less), thus negating any net benefit to the population overall.
As for companies lobbying to prevent changes to the existing program, he says that while he personally finds the lobbying process "pretty ugly," it's part of "normal commercial practice" and an appropriate exercise of companies' rights. "It's natural for them to want an outcome favorable to them," he says. Unless there's actual bribery, "It's not necessarily corrupt."