Historical clue formulations

• Amount measured in calories — 2026-02-26
• What's consumed — 2017-07-13
• Dieter's concern — 2010-01-01
• Quantity consumed — 2009-09-22
• Kind of valve — 2007-05-20
• Amount eaten — 2006-07-24
• Food — 2005-10-23
• Food or air — 2004-11-16
• ___ valve — 2004-04-15
• Kind of valve in a car — 2002-06-24
• Air, to a jet engine — 2001-05-10
• Outflow's opposite — 2000-10-24
• Amount eaten — 1998-05-18
• Type of value — 1995-07-30