1. Department of Psychology and Human Development, California Polytechnic
State University, San Luis Obispo, CA 934070, USA; fax: (1) 805-756-1134
2. Division of Nutritional Sciences, Cornell University, 216 Savage Hall,
Ithaca, NY 14853, USA; fax: (1) 607-255-1033
3. Food Consumption and Nutrition Division, International Food Policy
Research Institute, 1200 17th St., NW, Washington, DC 20036-3006, USA; fax:
(1) 202-467-4439