They are probably less likely to consume large amounts of prepackaged desserts, sodas and snack foods than their "English" neighbors, but that varies from community to community.
Cigarettes though.. the youth still love them.
However, your second point is not applicable. The Amish have a culinary tradition of their own that stems from 18th C German cooking adapted to American ingredients. Because they strictly limit their exposure to technology changes, they do more manual labor than is common for their neighbors, but this isn't correlated with a lack of desire for good (tasty, appetizing, visually appealing) food. If you tour Pennsylvania, Ohio and Indiana, you'll discover Amish foods and handmade goods being sold everywhere.