Lean and obese human subjects were observed during various single or mixed flavor meals of different palatability level. Chewing and swallowing responses were continuously recorded on an oscillograph, and a precise temporal analysis of their intrameal eating and drinking patterns was realized. Increasing palatability induced a decrease in chewing activity per food unit and, in the obese only, reduced the duration of intrameal pauses. In lean subjects, chewing time per food unit and intrameal pause duration increased from the beginning to the end of meals, probably due to developing satiation. Obese subjects appeared more stimulated than the lean at intermediate palatability levels. Prandial drinking occurred most often at the end of meals and may serve to enhance sensory stimulation. Mediation mechanisms are discussed.