pattern - What is a Healthy Word™?

If a word conforms to a special rule, I call it a Healthy Word™.

Use the following examples below to find the rule.

*These words are Extra Healthy™.

And, if you want to analyze, here is a CSV version:

HEALTHY WORD™, UNHEALTHY WORD™
DIABETOLOGY, DIETOLOGY
GASTRONOMES, CHEFS
HYDROBIOLOGY, BIOLOGY
GLAMOURED*, GLOOMED
ASTRONOMIC*, ASTROLOGIC
MACAROONS, MARSHMALLOWS
AERODYNAMICS*, AERONAUTICS
MONARCHIST, REPUBLICIST

GENEROUS, BENEVOLENT
LABYRINTHODONT, LABYRINTH
GRAMOPHONE, RADIO

Answer

OK, let's give this a go. A Healthy Word™ is a word which

contains all the letters of the word for a colour of red.

This fits because

DIABETOLOGY contains BLOOD, GASTRONOMES contains MAROON, HYDROBIOLOGY contains BLOOD, MACAROONS contains MAROON, MONARCHIST contains CRIMSON, GENEROUS contains ROSE, LABYRINTHODONT contains BLOOD, and GRAMOPHONE contains MAROON.

And the Extra Healthy Words™:

GLAMOURED contains RED and ROUGE, ASTRONOMIC contains MAROON and CRIMSON, and AERODYNAMICS contains RED and ROSE and CARMINE.

(Hat-tip to @MOehm for helping me to find a few of these.)