The effects of the acute administration of RU 486 on dietary fat preference in fasted lean and obese men.

The effects of RU 486, a potent glucocorticoid antagonist, on dietary fat preference were explored in obese men and lean controls in a double-blind crossover study. An oral 10 mg/kg dose of RU 486 or placebo was administered at midnight the second night of a 48-h hospital stay. Macronutrient and caloric intakes were calculated each day and a taste test of six commercial dairy products (fat content by weight < 0.5%, 2.0%, 3.3%, 10.5%, 18%, and 36%) was performed. Dairy products were judged for pleasantness, creaminess, and overall preference. Subjects were then asked to consume their favorite dairy product until sated. Urinary free cortisol (UFC) and plasma adrenocorticotropic hormone (ACTH), cortisol, insulin, and glucose were determined. Intake of a self-selected diet was recorded. As expected, in response to RU 486, UFC increased from 120 +/- 25 micrograms/24 h to 297 +/- 73 micrograms/24 h (p < 0.05) in obese men and from 81 +/- 10 micrograms/24 h to 357 +/- 109 micrograms/24 h (p < 0.05) in lean men. Plasma cortisol increased from 26.1 +/- 1.1 microgram/dl to 31.8 +/- 1.0 microgram/dl (p < 0.05) in obese men and from 26.1 +/- 1.7 micrograms/dl to 32.2 +/- 1.7 micrograms/dl (p < 0.05) in lean men. Plasma insulin was significantly higher in obese 24.6 +/- 3.2 microIU/ml than in lean men 12.8 +/- 1.1 microIU/ml (p = 0.0001) but was unaffected by RU 486. RU 486 did not decrease fat intake in either obese or lean men.(ABSTRACT TRUNCATED AT 250 WORDS)