Cortisol Changes with Weight Loss and Affects Food Intake from a Buffet

The purpose of this study was to determine if weight (wt) loss alters cortisol (COR) rhythm and if an association exists between [COR] and self‐selected food intake following an energy‐restricted diet. Obese men (n=2) and women (n=14) participated in this 15‐wk trial. All foods/beverages were provided and measured to achieve wt maintenance during 3‐wk baseline and wt loss during 12‐wk energy‐restriction (500 kcal/d reduced). Wt, body fat, intra‐abdominal fat (IAAT) were measured, and subjects participated in a test protocol that included ingestion of standardized breakfast and lunch and an ad libitum buffet‐style dinner at wks 3 & 15. Saliva was collected 10 times from waking to bedtime on test days. At wk 15 significant changes in wt, fat mass and IAAT occurred and averaged −6.4 ± 0.8 kg, −5.2 ± 0.6 kg, and −7.6 ± 1.6 cc. Peak salivary [COR] was reduced significantly, from 17.12 ± 1.99 at wk 3 to 12.97 ± 1.10 nmol/L at wk 15. Times of peak and nadir COR did not differ at wks 3 & 15, suggesting the absence of phase shift in COR rhythm. Buffet food intake was variable (kcal range=572 to 2636). Salivary [COR] measured immediately before and 30 min after dinner were positively associated with kcal intake (r=.50; p<0.05) and (r=0.72; p<0.01). Energy restriction and/or wt loss is associated with change in amplitude of COR rhythm. Also, [COR] around the meal and kcal consumed at the meal influence one another. Funded by Dairy Mgmt Inc & USDA.