Satiety following intake of potatoes and other carbohydrate test meals.

BACKGROUND AND AIMS: The study investigated satiation and satiety following intake of starch-rich side dishes representing a range of glycemic indices (GIs). METHODS: Twelve normal-weight (BMI = 22.4 ± SD 2.0) participants (6 male, 6 female, 22-30 years) received one of four side dishes or white bread (GI reference) in randomized order on five mornings, followed by an ad libitum lunch. Blood draws prior to test meal and during the 2 h before lunch measured plasma glucose and insulin concentrations. GI was calculated from glucose incremental area under the curve (AUC). Hunger, fullness, desire to eat and prospective consumption were rated just before blood draws. RESULTS: No significant difference was found in hunger or fullness AUCs between test meals. Both potato meals yielded lower desire to eat compared to pasta throughout the 2-hour period (p = 0.002). Total lunch energy intake did not differ. No significant correlations were found between test meal GI and ratings of hunger, fullness or energy intake at lunch meal. CONCLUSIONS: GI of energy-equivalent test meals did not predict satiety or lunch meal intake. There was evidence of reduced appetite following both potato meals relative to the other carbohydrate side dishes but no differences in subsequent intake.

Plasma cortisol levels in response to a cold pressor test did not predict appetite or ad libitum test meal intake in obese women.

Heightened cortisol response to stress due to hyperactivation of the hypothalamic-pituitary-adrenal (HPA) axis may stimulate appetite and food intake. In this study, we assessed cortisol responsivity to a cold pressor test (CPT) as well as appetite ratings and subsequent test meal intake (TMI) in obese women. Following an overnight fast on two counterbalanced days, 20 obese women immersed their non-dominant hand for 2min in ice water (CPT) or warm water (WW) as a control. Plasma cortisol (ng/ml), heart rate, and blood pressure, as well as ratings of stress, pain, and appetite, were serially acquired. An ad libitum liquid meal was offered at 45min and intake measured covertly. Fasting cortisol was higher at 15min (mean peak cortisol) following the CPT compared to WW. Higher stress was reported at 2 and 15min for the CPT compared to WW. Pain, an indirect marker of the acute stress, systolic and diastolic blood pressure increased following the CPT at 2min compared to WW. Hunger decreased after the CPT at 2 and 15min, and desire to eat ratings were lower following CPT compared to WW. Subjects did not have greater test meal intake (TMI) following CPT compared to WW. There was also no significant relationship between cortisol levels following stress and TMI, indicating that cortisol did not predict subsequent intake in obese women.