“…Elevated levels of the opioid peptide b-endorphin have been found in the pituitary of both genetically obese fa/fa rats and ob/ob mice (Margules, Moisset, Lewis, Shibuya, & Pert, 1978), and food intake has been shown to be reduced in response to naloxone. Preclinical studies indicate that opioid antagonists decrease intake of food and water (Beczkowska, Bowen, & Bodnar, 1992;Brown & Holtzman, 1981;Thornhill, Taylor, Marshall, & Parent, 1982) as well as sweet solutions and high-fat foods (Beczkowska et al, 1992;Islam & Bodnar, 1990). Although studies in human subjects indicate that naltrexone alters eating behavior and reduces intake of food and caloric intake, the influence of naltrexone on weight in normal and obese patients remains equivocal (see de Zwaan & Mitchell, 1992, for review).…”