Journal Of Consulting o»(t Clinical Psychology 1975, Vol. 43, No. 2, 123-125
Relationship Between Eating Rates and Obesity Donna J, Gaul, W. Edward Craighead, and Michael J. Mahoney Pennsylvania State University A comparison was made of the eating behaviors of obese and nonobese subjects in a naturalistic setting. It was found that obese subjects took more bites, performed fewer chews per bite, and spent less time chewing than did nonobese subjects. The clinical implications of these data are discussed.
In their recent review Stunkard and Mahoney (in press) concluded that behavior modification techniques have demonstrated considerable effectiveness in the treatment of obesity. Many of these techniques were based in part on the behavioral analysis of eating patterns first presented by Ferster, Nurnberger, and Levitt (1962). An implicit assumption of many behavior modification programs has been that eating patterns differ for obese and nonobese people. Specifically, it has been presumed that overweight individuals eat faster and take fewer bites (cf. Stuart & Davis, 1972). However, virtually no empirical data regarding that assumption have been presented. The purpose of the present study was to determine if obese people consume their food more rapidly than nonobese people, and if consummatory behaviors (chewing and drinking) differ for the two groups. METHOD Subjects One hundred subjects were chosen for observation at an eating establishment that specializes in the sale of hamburgers, french fried potatoes, and soft drinks. One criterion for subject selection was that he purchase all three items and only those items. Additionally, for a subject to be included he had to sip his drink through a straw (which nearly all people did). Finally, the subject had to be between the ages of 18 and 35 in the opinion of two trained observers. As each potential subject purchased his food, the two observers independently categorized them on age and obesity. The first SO males (25 obese, 25 nonobese) and first SO females (25 obese, Requests for reprints should be sent to W. Edward Craighead, Department of Psychology, 512 Moore Building, Pennsylvania State University, University Park, Pennsylvania 16802.
25 nonobese) to meet joint agreement criteria were included in the study.
Procedure The consummatory behaviors of each subject were unobtrusively recorded by two trained observers. Any subject who indicated awareness of being observed was excluded from the study. Observations were made, one subject at the time, in order of subjects' appearance until the requisite number (n = 25) for each cell was obtained. Beginning with the subject's first bite or sip of drink, frequency counts were taken, by both observers for five minutes. Data were obtained for the following dependent measures: number of bites taken during the five minutes (three french fries were considered equal to one bite of hamburger), number of chews per bite, total number of seconds (of possible 300) spent chewing, and total number of sips of soft drink.
RESULTS Interobserver agreement was calculated by dividing the number of ratings for which both observers agreed by the number of agreements plus disagreements and multiplying the quotient by 100. Interobserver agreement was 100% for all measures except number of chews per bite where the average interobserver agreement was 92% (range = 87%100%). The means and standard deviations for all the dependent measures are presented in Table 1. The data represent averages between observers for all measures. All data were submitted to 2 X 2 (Obesity X Sex) analyses of variance. The main effect for obesity was significant for number of bites taken (F = 63.2, df = 1/96, p < .001), number of chews per bite (F = 126.8, dj = 1/96, P < .001), and for total amount of time spent chewing (F = 70.1, dj = 1/96, p < .001).
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124
D. J. GAUL, W. E. CRAIGHEAD, AND M. J. MAHONEV TABLE 1
rapid eaters (Ferster et al., 1962). Therapeutic strategies aimed at reducing eating pace may therefore be effective. However, the fact that obese subjects took more bites than Obese Nonobese nonobese subjects is at least partially conCondition tradictory to the popular recommendation Males Females Males Females that overweight individuals increase the number of bites they take (Stuart & Davis, 1972). No. bites Unless this increase is accompanied by a M 17.04 16.84 13.00 12.32 SD 2.20 2.51 2.68 3.26 slowing of the eating pace, countertherapeutic No. of chews per results might ensue. bite The dramatic difference between groups on M 9.76 9.20 21.36 18.84 the mastication variable also deserves comSD 11.51 4.72 3.23 3.03 Time spent ment. Although relatively little therapeutic chewing attention has been paid to this dimension, it (in seconds) seems possible that increased mastication M 104.44 104.08 161.60 153.48 may facilitate weight reduction. This specuSD 35.42 33.41 23.01 33.89 No. sips lation is consistent with recent findings on 8.00 6.56 7.44 M 7.28 the role of food texture and mastication in SD 2.02 1.36 1.84 1.29 satiety (Balagura, 1973). The strategy of counting bites (Stuart & Davis, 1972) may be contraindicated unless Obese subjects took more bites (M = 16.94) obese clients are given specific standards and than nonobese subjects (M — 12.66), per- eating behavior guidelines to pursue. At an formed fewer chews per bite (M obese = intuitive level, the overweight person might 9.24, M nonobese = 18.60), spent less time interpret this self-monitoring task as sugchewing (M obese = 104.26, M nonobese = gesting that he should take fewer bites. Were this to result, he might inadvertently develop 1S7.S4). There was a significant main effect for sex the maladaptive pattern of rapid, large (but (F - 5.8, dj = 1/96, p < .018) and a sig- few) bites. A laboratory study subsequent to nificant .Sex X Obesity interaction effect (F the one described in this article asked obese = 3.7, dj = 1/96, p < .056) for total num- and nonobese individuals to eat a standardber of sips taken. Males (M = 7.72) took a ized meal in a laboratory setting. Within the greater total of sips than did females (M = next three days the subjects were asked to 6.92); however, this was primarily the result count the bites they took while consuming the of obese males (M = 8.00) who took a sig- same standardized meal. Extensive intersubnificantly greater number of sips than did the ject variability was encountered. Self-monitoring did not have any systematic effect on obese female subjects (If = 6.56). eating pace for either group of individuals. A noteworthy finding, however, was that obese DISCUSSION subjects were significantly less accurate in The foregoing results suggest several clinic- their self-monitoring than nonobese subjects ally relevant implications for the behavioral (£/2 = 4.5> m = 6, «2 = 7, p< .05). treatment of obesity. To begin with, it does One final comment has to do with the asappear that there are differences in the eatsumption that obese individuals will lose ing styles of obese and nonobese individuals. Obese subjects in the present study spent less weight if they adopt the eating styles of nortime chewing than nonobese subjects and took mal persons (Stunkard & Mahoney, in press). more bites during the five-minute observation While there is strong evidence that modifying period. This latter finding corroborates the what people eat (calorically) can result in notion that overweight individuals are often weight loss, the data on modifying how they MEANS AND STANDARD DEVIATIONS FOR ALL DEPENDENT MEASURES FOR ALL GROUPS
RELATIONSHIP BETWEEN EATING RATES AND OBESITY eat are less conclusive. Further inquiries need to evaluate the relationship between these ." variables, REFERENCES Baiagura, S. Hunger: A biopsychological analysis, New York: Basic Books, 1973. i'erster, C. B., Nurnberger, J. I., & Levitt, E. B.
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The control of eating. Journal of Mathetics, 1962, 1, 87-109. Stuart, R. B., & Davis, B. Slim chance in a fat world. Champaign, 111.: Research Press, 1972. Stunkard, A, J,, & Mahoney, M. J. Behavioral treatment of the eating disorders. In H. Leitenberg (Ed.), Handbook of behavior modification. New York: Appleton-Century-Crofts, in press. (Received May 23, 1974)
Relationship Between Eating Rates and Obesity Donna J, Gaul, W. Edward Craighead, and Michael J. Mahoney Pennsylvania State University A comparison was made of the eating behaviors of obese and nonobese subjects in a naturalistic setting. It was found that obese subjects took more bites, performed fewer chews per bite, and spent less time chewing than did nonobese subjects. The clinical implications of these data are discussed.
In their recent review Stunkard and Mahoney (in press) concluded that behavior modification techniques have demonstrated considerable effectiveness in the treatment of obesity. Many of these techniques were based in part on the behavioral analysis of eating patterns first presented by Ferster, Nurnberger, and Levitt (1962). An implicit assumption of many behavior modification programs has been that eating patterns differ for obese and nonobese people. Specifically, it has been presumed that overweight individuals eat faster and take fewer bites (cf. Stuart & Davis, 1972). However, virtually no empirical data regarding that assumption have been presented. The purpose of the present study was to determine if obese people consume their food more rapidly than nonobese people, and if consummatory behaviors (chewing and drinking) differ for the two groups. METHOD Subjects One hundred subjects were chosen for observation at an eating establishment that specializes in the sale of hamburgers, french fried potatoes, and soft drinks. One criterion for subject selection was that he purchase all three items and only those items. Additionally, for a subject to be included he had to sip his drink through a straw (which nearly all people did). Finally, the subject had to be between the ages of 18 and 35 in the opinion of two trained observers. As each potential subject purchased his food, the two observers independently categorized them on age and obesity. The first SO males (25 obese, 25 nonobese) and first SO females (25 obese, Requests for reprints should be sent to W. Edward Craighead, Department of Psychology, 512 Moore Building, Pennsylvania State University, University Park, Pennsylvania 16802.
25 nonobese) to meet joint agreement criteria were included in the study.
Procedure The consummatory behaviors of each subject were unobtrusively recorded by two trained observers. Any subject who indicated awareness of being observed was excluded from the study. Observations were made, one subject at the time, in order of subjects' appearance until the requisite number (n = 25) for each cell was obtained. Beginning with the subject's first bite or sip of drink, frequency counts were taken, by both observers for five minutes. Data were obtained for the following dependent measures: number of bites taken during the five minutes (three french fries were considered equal to one bite of hamburger), number of chews per bite, total number of seconds (of possible 300) spent chewing, and total number of sips of soft drink.
RESULTS Interobserver agreement was calculated by dividing the number of ratings for which both observers agreed by the number of agreements plus disagreements and multiplying the quotient by 100. Interobserver agreement was 100% for all measures except number of chews per bite where the average interobserver agreement was 92% (range = 87%100%). The means and standard deviations for all the dependent measures are presented in Table 1. The data represent averages between observers for all measures. All data were submitted to 2 X 2 (Obesity X Sex) analyses of variance. The main effect for obesity was significant for number of bites taken (F = 63.2, df = 1/96, p < .001), number of chews per bite (F = 126.8, dj = 1/96, P < .001), and for total amount of time spent chewing (F = 70.1, dj = 1/96, p < .001).
123
124
D. J. GAUL, W. E. CRAIGHEAD, AND M. J. MAHONEV TABLE 1
rapid eaters (Ferster et al., 1962). Therapeutic strategies aimed at reducing eating pace may therefore be effective. However, the fact that obese subjects took more bites than Obese Nonobese nonobese subjects is at least partially conCondition tradictory to the popular recommendation Males Females Males Females that overweight individuals increase the number of bites they take (Stuart & Davis, 1972). No. bites Unless this increase is accompanied by a M 17.04 16.84 13.00 12.32 SD 2.20 2.51 2.68 3.26 slowing of the eating pace, countertherapeutic No. of chews per results might ensue. bite The dramatic difference between groups on M 9.76 9.20 21.36 18.84 the mastication variable also deserves comSD 11.51 4.72 3.23 3.03 Time spent ment. Although relatively little therapeutic chewing attention has been paid to this dimension, it (in seconds) seems possible that increased mastication M 104.44 104.08 161.60 153.48 may facilitate weight reduction. This specuSD 35.42 33.41 23.01 33.89 No. sips lation is consistent with recent findings on 8.00 6.56 7.44 M 7.28 the role of food texture and mastication in SD 2.02 1.36 1.84 1.29 satiety (Balagura, 1973). The strategy of counting bites (Stuart & Davis, 1972) may be contraindicated unless Obese subjects took more bites (M = 16.94) obese clients are given specific standards and than nonobese subjects (M — 12.66), per- eating behavior guidelines to pursue. At an formed fewer chews per bite (M obese = intuitive level, the overweight person might 9.24, M nonobese = 18.60), spent less time interpret this self-monitoring task as sugchewing (M obese = 104.26, M nonobese = gesting that he should take fewer bites. Were this to result, he might inadvertently develop 1S7.S4). There was a significant main effect for sex the maladaptive pattern of rapid, large (but (F - 5.8, dj = 1/96, p < .018) and a sig- few) bites. A laboratory study subsequent to nificant .Sex X Obesity interaction effect (F the one described in this article asked obese = 3.7, dj = 1/96, p < .056) for total num- and nonobese individuals to eat a standardber of sips taken. Males (M = 7.72) took a ized meal in a laboratory setting. Within the greater total of sips than did females (M = next three days the subjects were asked to 6.92); however, this was primarily the result count the bites they took while consuming the of obese males (M = 8.00) who took a sig- same standardized meal. Extensive intersubnificantly greater number of sips than did the ject variability was encountered. Self-monitoring did not have any systematic effect on obese female subjects (If = 6.56). eating pace for either group of individuals. A noteworthy finding, however, was that obese DISCUSSION subjects were significantly less accurate in The foregoing results suggest several clinic- their self-monitoring than nonobese subjects ally relevant implications for the behavioral (£/2 = 4.5> m = 6, «2 = 7, p< .05). treatment of obesity. To begin with, it does One final comment has to do with the asappear that there are differences in the eatsumption that obese individuals will lose ing styles of obese and nonobese individuals. Obese subjects in the present study spent less weight if they adopt the eating styles of nortime chewing than nonobese subjects and took mal persons (Stunkard & Mahoney, in press). more bites during the five-minute observation While there is strong evidence that modifying period. This latter finding corroborates the what people eat (calorically) can result in notion that overweight individuals are often weight loss, the data on modifying how they MEANS AND STANDARD DEVIATIONS FOR ALL DEPENDENT MEASURES FOR ALL GROUPS
RELATIONSHIP BETWEEN EATING RATES AND OBESITY eat are less conclusive. Further inquiries need to evaluate the relationship between these ." variables, REFERENCES Baiagura, S. Hunger: A biopsychological analysis, New York: Basic Books, 1973. i'erster, C. B., Nurnberger, J. I., & Levitt, E. B.
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The control of eating. Journal of Mathetics, 1962, 1, 87-109. Stuart, R. B., & Davis, B. Slim chance in a fat world. Champaign, 111.: Research Press, 1972. Stunkard, A, J,, & Mahoney, M. J. Behavioral treatment of the eating disorders. In H. Leitenberg (Ed.), Handbook of behavior modification. New York: Appleton-Century-Crofts, in press. (Received May 23, 1974)
