In “The Gluten Lie,” reviewed in this issue beginning on Page 1, author Alan Levinovitz blames the public’s current tendency toward convoluted thinking regarding issues of nutrition in part on what he calls the “monotonic mind.” Coined originally by psychologist Paul Rozin, monotonic refers to a person who believes something harmful at high levels also is harmful at low levels.

“Nutrition isn’t monotonic,” Mr. Levinovitz said. “A glass of wine each day won’t kill you, but 40 glasses of wine per day definitely will.” He said monotonic thinking helps explain a study in which a third of Americans said a diet with no sugar at all was healthier than a diet with a “pinch” of sugar.

A tendency toward monotonic thinking at the Food and Drug Administration was on display last week with its decision to ban partially hydrogenated oils by 2018. Explaining its decision, the F.D.A. acknowledged that average daily intake of phos had plunged to 1.0 gram in 2012 from 4.6 grams in 2003.

To justify the ban, the F.D.A pointed to 90th percentile consumers of trans fat, high-intake individuals still consuming 4.2 grams per day. The F.D.A. has claimed the ban will save thousands of lives. Still, it stands to reason these theoretical at-risk individuals, excessive consumers of treats laden with calorically-dense ingredients, won’t be escaping health challenges after the ill-conceived ban of phos has been fully implemented.