A study conducted in the laboratory revealed the existence of a "window" during which patients with renal failure appreciate the protein-rich foods. This period, located immediately after the dialysis, is likely related to the purification of plasma products resulting from protein catabolism. It therefore appears necessary to understand the mechanisms that may explain these changes by measurements of ghrelin (orexigenic hormone), leptin (anorectic hormone) and plasma amino acids.

In 24 patients with renal failure treated by hemodialysis, it is evaluated (at 8:00 am and at 11:00 am), a day without hemodialysis and another day after the hemodialysis:

• Hunger sensation,

• Olfactory liking assessed separately for 6 foods (2 carbohydrate-, 2 fat- and 2 protein-rich foods) and 2 non-alimentary products,

• Food wanting evaluated by the sequential presentation of 18 images of food (6 fat-, 6 carbohydrate- and 6 protein-rich foods),

• Two blood samples for the assays of leptin, ghrelin, creatinine, albumin and pre-albumin as well as plasma amino acids.

  24 healthy subjects are also evaluated in order to compare the results from patients to those of control subjects.

Inclusion Criteria:

• Patients and healthy subjects were included if they were aged between 18 and 80 years

Exclusion Criteria:

• diabetes, advanced undernutrition (BMI < 17.5 kg m-2, prealbumin < 250 mg.L-1), congestive heart failure, acute or chronic infection, ongoing antibiotic treatment, active cancer, liver cirrhosis, smoking (more than 5 cigarettes/day), alcohol consumption (more than 3 units/day), aversion to the foods eaten or smelt during the study, impaired comprehension of the cognitive tasks

hemodialysis centers of Clinique Drevon, Dijon, France la Breuchillière, Saint Apollinaire, France University Hospital, Dijon, France Macon Hospital, Macon, France