We questioned whether adrenergic amines extracted from the Seville orange Citrus Aurantium (CA) increases metabolic rate and enhance the thermic response to a 1.7MJ mixed meal (TEF) in lean and obese men and women; the latter had upper-body obesity, a condition associated with defective TEF, attributed to altered SNS. Nine lean (7M, 2F; BMI: 23 +/- 1 k g/m 2; waist circumference: 78 +/- 2 cm) and 13 obese (4M, 9F; BMI: 35 +/- 1 kg/m2; waist circumference: 105 +/- 3 cm) subjects were studied. With CA: (1) RMR increased more in men vs women (94 vs 42 kJ over 5 h), independently of body composition; (2) urinary epinephrine excretion increased in both groups and dopamine only in men. A 17% lower TEF in obese subjects was no longer significant when controlled for gender. By contrast, there was an effect of gender on TEF that remained significant when adjusted for measures of obesity. Women had a lower TEF that increased to values no longer different from men with CA. CA did not affect TEF in men. CA had no cardiovascular effects. Thus, CA ingestion increased thermogenesis by 4% above RMR and enhanced the lower TEF of women by 29% (46kJ).

No description available.