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Human subjects controlled ingestion of liquid diet orally or intragastrically by activating a pump. When the pump rate was constant, intragastric intakes were comparable to oral intakes. A series of experiments was performed to assess the relative contributions of oral and gastric factors in short-term regulation of food intake. Subjects overate when fed simultaneously by the oral and intragastric routes. Subjects did not respond to caloric dilution within one meal when ingesting intragastrically. When three Metrecal meals a day were taken intragastrically for 2 days, subjects ingested an adequate amount of calories and maintained their weights.The relative contributions of oropharyngeal, gastric, and postabsorptive factors in the production of satiety have been successfully explored in several animal species, where satiety is denned as the cessation of food intake (Janowitz & Grossman, 1949;Mook, 1963). Interspecies differences have been marked, however, and therefore understanding hunger and satiety in man in light of these studies is not a simple extrapolation. Only recently have there been direct studies of eating behavior in man (Hashim & Van Itallie, 1964; Jordan, Stellar, & Duggan, 1968; Jordan, Wieland, Zebley, Stellar, & Stunkard, 1966) that could parallel these animal experiments. It is interesting, however, that in 1883 William Beaumont (reprinted 1959), in his classic studies of the gastric fistula of Alexis St. Martin, had remarkably modern insight into the roles of the oral and postingestional components of the regulatory apparatus in man. He suggested in the report of his work that because of the overriding importance of oral factors, man's capacity for regulation was far from per-

A method for the direct measurement of food intake in man is described. This method provides a means for independently studying many of the variables which are thought to operate in the control of food intake. A liquid diet from a hidden reservoir was ingested through a straw during a 20-min. breakfast or lunch meal. Subjects were tested at the same time each day for several weeks. Stable ingestion patterns emerged after four or five trials. The ingestion of a constant amount of liquid diet at various intervals before the test meal depressed intake as a function of the time interval. Subjective hunger ratings correlated well with rate and amount ingested and were reduced appropriately by ingestion prior to the test meal. R, .ECENT clinical studies of eating behavior in man have revealed a variety of disordered patterns, such as the nighteating and binge-eating syndromes of the obese, 15 and the often bizarre eating patterns in anorexia nervosa. 2 In addition, new experimental techniques used in the study of man have demonstrated

17 human subjects ate 20-min. meals of Metrecal through a straw connected to a hidden reservoir. Oral preloads of Metrecal were administered before the meals, and these varied 20-120% of the amount of the base-line meal intake and were given 1-120 min. before the meal. Test-meal intake was depressed as a function of the size of the preload; however, the subjects did not take the preload fully into account and they overate. Depression of intake was maximal 1-5 min. for some subjects and 15-30 min. for others. Subjective ratings of hunger paralleled the variations in intake produced by preloading. The results are discussed in terms of the joint operation of oropharyngeal and gastric postingestional factors.