The title promises something light and modern, a diet plan, but the poem quickly turns it into something harsher. The speaker wants to become thin and does it by marrying their bones to the road, which suggests long, punishing walking, a body worn down until it is mostly frame. The word "wed" makes it sound like a vow, as if this is a commitment for life rather than a quick fix.
The second stanza is more puzzling. "Today's new yesterday" seems to describe days piling up, each one turning into the last, while "a cross" brings in the idea of burden or sacrifice. The weight being lost may be more than physical. The final image, "a dark and dirty supper for the eyes," suggests that what the speaker feeds on is not food but what they see along the way. The mood is stark, hungry, and quietly ironic, with a sense of endurance that borders on suffering.