Dietary fat reduction behaviors in college students - Science Direct

Appetite (2001) 36, 51±56 doi:10.1006/appe.2000.0383, available online at http://www.idealibrary.com on

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Original Article

Dietary fat reduction behaviors in college students: relationship to dieting status, gender and key psychosocial variables M. Liebman, B. A.Cameron, D. K.Carson, D. M. Brown and S. S. Meyer Department of Family and Consumer Sciences,University of Wyoming (Received15 July1999, revision18 September 2000, accepted in revised form 20 October 2000, published electronically19 December 2000)

The primary objectives were to assess dietary fat reduction/avoidance behaviors within a sample of college students, and to assess the strength of the relationship between self reported fat avoidance and a number of variables including body mass index (BMI), self-esteem, and responses to the Eating Disorder Inventory (EDI) and Eating Attitudes Test (EAT). A total of 210 female and 114 male undergraduate students were administered a food habits questionnaire (which assessed four dietary fat reduction behaviors), the EDI, the dieting subscale of the EAT, and the Coopersmith Self-Esteem Inventory. Measured heights and weights were used to compute BMI. Thirty-eight percent of the females and 13% of the males reported that they had dieted with the express purpose of losing weight in the past 12 months. The finding that females in general and female dieters in particular, scored higher on the EAT dieting subscale, and relied on three of the four dietary fat reduction behaviors to a greater extent than did males, supports the assertion that women rely heavily on dietary fat avoidance as a method to reduce caloric intakes. In females, the finding that a greater degree of fat avoidance was associated with significantly lower levels of self-esteem and higher scores on the EAT and on six of the eight EDI subscales suggested that fat avoidance may be a predictor of eating pathology and/or psychosocial problems in college-aged women. # 2001 Academic Press

Introduction Based on recent national surveys, the prevalence of overweight among adult men and women is increasing. Data from NHANES III, 1988±1994, indicate that 63% of adult men and 55% of adult women are overweight, defined as a body mass index (BMI) of 25
0 or more (Must et al., 1999). BMI, computed as weight in kilograms divided by the square of height in meters, is widely used in research and clinical practice. BMI is more strongly associated with percent body fat and health complications than is weight (Expert Panel on the Identification, Evaluation, and Treatment of Overweight in Adults, 1998).

Address correspondence to: Dr Michael Liebman, Department of Family and Consumer Sciences, University of Wyoming, P.O. Box 3354, Laramie, WY 82071-3354, U.S.A. 0195±6663/01/010051+06 $35.00/0

During the last few decades, there has been a marked trend toward an increasingly thin, and yet physically fit, ideal of female attractiveness (Wiseman et al., 1992). Dieting to lose weight is a widespread practice in the U.S., and a greater percentage of women than men report dieting sometime during their lives (Jeffrey et al., 1991; Horm & Anderson, 1993). Dieting, especially among women, appears to be related to lower selfesteem, greater depression, and a higher level of body dissatisfaction (French et al., 1995b; Polivy & Herman, 1987). Moore-Streigel et al. (1986) showed that low selfesteem and negative body image were antecedents of attempts at weight loss by women. Chronic dieters, or restrained eaters, consciously limit food consumption, are highly concerned with their body weight, and may alternate periods of limited food consumption with periods of overeating (Tuschl et al., 1990). Lower dietary fat intakes have been reported among adolescent (Contento et al., 1995) as well as adult # 2001 Academic Press

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M. Liebman et al.

chronic dieters (Tuschl et al., 1990). Although many individuals make an effort to consume low-fat diets, it is unclear which specific dietary practices are employed to lower total fat intakes. The primary objective of this study was to assess the strength of the relationship between self reported fat avoidance and a number of variables including BMI, self-esteem, and responses to the Eating Disorder Inventory (EDI) and Eating Attitudes Test (EAT). A secondary objective was to assess degree of reliance by college undergraduates on specific dietary fat reduction practices.

Methods Subjects Subjects were male (N ˆ 114, age range 18±40 years, mean 22
3 years) and female (N ˆ 210, age range 17±55 years, mean 21
2 years) students enrolled in either introductory nutrition or marriage/family courses at a major western university (N ˆ 212) and introductory psychology, sociology, or communication courses at a community college in the same state (N ˆ 112). Subjects were either awarded extra credit for participation, or in some classes participation was totally voluntary. Greater than 90% of the students in each class chose to participate.

Measures Participants filled out a series of inventories which elicited information related to various dietary behaviors, self esteem, and psychological and behavioral traits commonly associated with eating disorders. The following instruments were used in the study.

Dieting subscale of Eating AttitudesTest (EAT) This is a 13-item subscale designed to assess both the degree of pathological avoidance of fattening foods and preoccupation with body shape. This factor was demonstrated to be both reliable ( ˆ 0
90) and highly correlated with the total EAT (26-item) score (r ˆ 0
93). Higher scores connote higher levels of dieting behavior (Garner et al., 1982).

Food Habits Questionnaire This is an 18-item questionnaire developed to assess four relevant dimensions of dietary behavior associated with selecting diets low in fat (fat avoidance): modifying meat to decrease fat (modify meat); avoiding fat as a seasoning (avoid fat); substituting high-fat foods with specially manufactured lower-fat foods

(fat substitution); and replacing high-fat foods with low-fat alternatives (fat replacement). The scales had high test±retest and internal consistency reliabilities. Lower scores connote greater levels of fat avoidance (Kristal et al., 1990).

Self-Esteem Inventory (adult form) This is a 25-item scale appropriate for individuals aged 16 and above. Pretest reliability using college age students was 0
80 for males and 0
82 for females. Higher scores connote higher levels of self-esteem (Coopersmith, 1981).

Eating Disorder Inventory (EDI) This is a 64-item, multiscale measure designed for the assessment of psychological and behavior traits commonly associated with eating disorders. The EDI consists of 8 subscales: drive for thinness, bulimia, body dissatisfaction, ineffectiveness, perfectionism, interpersonal distrust, interoceptive awareness, and maturity fears. Higher scores connote higher levels of these traits (Garner et al., 1983). In addition, participants provided demographic data including age, sex, academic year, academic major, place of residence (on or off campus), and self-reported weight and height. After completion of the questionnaires, each subject's weight and height were measured with a beam balance scale and attached stadiometer. Actual weight and height were used to compute BMI. BMI, calculated as weight (in kilograms) divided by the square of height (in meters), is a widely used indice for estimating an individual's degree of underweight/overweight. Participants were subdivided into ``dieters'' and ``non-dieters'' on the basis of their response to the question: ``Have you dieted in the past 12 months with the express purpose of losing weight?''.

Statistics Differences in dependent variables (EAT total score, EDI subscale scores, self-esteem inventory score, and eating behavior subscale scores) between males and females and between dieters and non-dieters were tested with a two-way analysis of variance. t-tests were used to assess differences in dependent variables between subjects in the lowest and highest quintiles for fat avoidance scores. Pearson correlation coefficients were also computed to further assess the relationship between fat avoidance and key variables of interest. SAS software (Statistical Analysis System Institute, Inc, Cary, NC) was used to compute all statistical analyses.

Dietary fat reduction

Results Of the 114 males and 210 females who participated in this study, 15 males (13%) and 84 females (38%) reported that they had dieted with the express purpose of losing weight in the past 12 months. A comparison of key variables of interest between males and females and between dieters and non-dieters is summarized in Table 1. Compared to males, females had a significantly lower mean BMI; lower self-esteem; higher EDI subscale scores for drive for thinness, body dissatisfaction, bulimia, ineffectiveness, and interoceptive awareness; a higher mean score for the EAT; and scores indicative of greater reliance on three of the four dietary behaviors associated with selecting diets low in fat (i.e. modifying high-fat/meat foods, substituting low-fat foods for their higher fat counterparts, and replacing high-fat foods with low-fat alternatives). Compared to non-dieters, dieters had a significantly higher BMI and EAT dieting subscale score, and higher scores on four of the EDI subscales (drive for thinness, bulimia, body dissatisfaction, and interoceptive awareness). Dieters were also characterized by scores which indicated a greater reliance on modifying high-fat/meat foods, avoiding fat, and replacing highfat foods with low-fat alternatives. Statistically significant diet by sex interactions for the EAT and drive for thinness subscale scores indicated that the differences in scores between dieters and non-dieters were more pronounced in females than in males. Significant

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interactions for the interoceptive awareness scores and for the dietary behaviors fat replacement and fat substitution indicated that dieter/nondieter differences occurred only within the female sub-population. The strength of the relationships between selfreported fat avoidance and a number of variables including BMI, self-esteem, and responses to the EDI and EAT were assessed by comparing scores of these variables of interest between subjects falling in the lowest (Q1) and highest (Q5) quintiles for fat avoidance (Table 2). In females, a greater degree of fat avoidance (scores for subjects falling within Q1 as compared to those falling within Q5) was associated with significantly lower levels of self-esteem and higher scores on the EAT and on six of the eight EDI subscales (drive for thinness, body dissatisfaction, bulimia, ineffectiveness, interpersonal distrust, and interoceptive awareness). In males, a greater degree of fat avoidance was only significantly related to higher scores on the EAT and the drive for thinness and perfectionism subscales of the EDI. Statistically significant correlations within the female sub-population between fat avoidance scores and scores for EAT (r ˆ ÿ0
47), drive for thinness (r ˆ ÿ0
39), body dissatisfaction (r ˆ ÿ0
18), bulimia (r ˆ ÿ0
17), ineffectiveness (r ˆ ÿ0
16), interpersonal distrust (r ˆ ÿ0
14), and interoceptive awareness (r ˆ ÿ0
18) are supportive of the findings described above. Within the male sub-population, fat avoidance scores were significantly correlated with those for EAT (r ˆ ÿ0
30),

Table 1. Mean body weight, BMI and inventory responses according to gender and dieting status Male

Body weight (lb) BMI EAT dieting subscale total EDI subscales Drive for thinness Bulimia Body dissatisfaction Ineffectiveness Perfectionism Interpersonal distrust Interoceptive awareness Maturity fears Self esteem index total Eating behavior subscales Modify meat Avoid fat Fat replacement Fat substitution a

Female

F Value

Dieter (N ˆ 15)

Non-dieter (N ˆ 99)

Dieter (N ˆ 84)

Non-dieter (N ˆ 126)

Diet

Sex

Diet*sex

207
6  38
2a 29
7  3
7 4
7  4
1

180
6  32
5 25
6  4
0 2
0  2
7

149
4  31
6 24
8  5
4 11
7  8
2

140
7  23
4 23
3  3
7 4
8  5
2

15
3*** 17
8*** 31
2***

115
9*** 28
5*** 32
6***

4
0* 3
6 5
6*

3
8  4
0 2
0  2
3 5
3  4
8 2
1  2
2 6
8  3
3 2
9  2
6 2
9  2
5 4
1  2
6 81
3  16
1

1
3  1
9 1
6  1
7 3
6  3
8 1
7  2
3 7
9  3
4 3
4  3
1 3
0  3
2 4
0  3
2 80
9  15
4

10
6  5
1 4
1  3
8 15
3  6
6 5
0  5
0 8
3  3
5 3
8  3
7 6
8  5
2 5
4  3
8 69
2  19
2

5
0  7
7 2
3  3
0 10
4  7
7 3
1  4
2 7
6  4
0 2
4  2
7 4
0  3
9 3
8  2
6 76
6  18
0

39
0*** 6
2* 11
5*** 3
7 0
2 0
8 4
8* 3
4 1
6

66
6*** 9
7** 72
6*** 12
5*** 1
1 0 15
5*** 1
2 9
1*

5
4* 2
3 2
6 1
6 2
2 3
5 5
6* 2
5 2
0

2
7  0
7 2
6  0
6 3
5  0
5 3
2  0
4

2
9  0
7 2
9  0
7 3
5  0
5 3
2  0
6

2
0  0
8 2
3  0
9 2
8  0
9 2
2  0
8

2
3  0
8 2
7  0
8 3
3  0
7 2
7  0
7

4
4* 8
1* 4
6* 3
7

27
3*** 2
6 16
3*** 46
8*

0 0
1 4
1* 5
1*

x  SD. *p < 0
05; **p < 0
01 ***p < 0
001.

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M. Liebman et al.

Table 2. BMI, dieting, and psychosocial subscale scores for subjects in the lowest and highest quintiles for fat avoidance Fat avoidance score (females) a

Q5

Q1 Self esteem index total BMI EAT dieting subscale total EDI subscales Drive for thinness Body dissatisfaction Bulimia Ineffectiveness Perfectionism Interpersonal distrust Interoceptive awareness Maturity fears

b

67
3  19
8 (43) 22
9  3
7 (46) 13
1  8
6 (46) 10
9  5
6 (46) 14
2  6
8 (46) 3
9  3
6 (46) 5
5  5
0 (46) 8
5  3
6 (46) 4
1  3
6 (46) 7
2  5
8 (46) 5
2  3
2 (46)

Fat avoidance score (males) T

76
8  15
9 (45) ÿ2
5* 23
6  6
3 (45) ÿ0
6 3
3  4
3 (45) 6
9*** 4
3  4
6 (45) 9
8  7
8 (45) 2
1  3
4 (45) 2
8  4
6 (45) 7
4  4
1 (45) 2
5  3
3 (45) 4
4  4
7 (45) 4
9  3
8 (45)

6
1*** 2
9** 2
4* 2
7** 1
2 2
2* 2
5* 0
4

Q1

Q5

T

82
5  13
4 (24) 27
1  4
8 (24) 4
0  4
4 (24)

80
3  16
9 (24) 25
3  3
8 (25) 1
4  2
0 (25)

0
5 1
4 2
6*

2
5  2
7 (24) 3
8  3
7 (24) 1
9  2
3 (24) 1
7  2
4 (24) 9
6  3
4 (24) 3
2  3
2 (24) 3
0  3
0 (24) 3
5  2
8 (24)

1
0  1
7 (25) 3
6  3
7 (25) 2
0  1
6 (25) 1
7  2
2 (25) 7
3  3
0 (25) 3
4  3
3 (25) 3
0  3
6 (25) 4
2  3
6 (25)

2
3* 0
2 ÿ0
1 0
1 2
6* ÿ0
3 ÿ0
1 ÿ0
7

a

Q1 and Q5 refer to the lowest and highest quintiles, respectively, for fat avoidance scores. x  SD (number of subjects). *p < 0
05; **p < 0
01; ***p < 0
0001.

b

drive for thinness (r ˆ ÿ0
26) and perfectionism (r ˆ ÿ0
25). Since low fat avoidance scores from the food habits questionnaire indicate greater reliance on dietary behaviors related to selecting diets low in fat, the negative correlations stated above actually indicate positive associations.

Discussion The findings of a high prevalence of dieting behavior within this population of college students and a higher prevalence among females (38%) compared to males (15%) are consistent with results of previous studies conducted in High School students (Serdula et al., 1993; ``National Adolescent'', 1989; French & Jeffrey, 1994), studies conducted in college environments (Hartung, 1997), and studies which used adult populations of individuals aged 18 year and older (Serdula et al., 1993) and 25 year and older (Horm & Anderson, 1993). One root cause of the high prevalence of dieting among women appears to be the intense preoccupation with body sizes and shapes in economically advantaged societies. Because of the high value placed upon appearance, self-worth is enhanced for those who are perceived as attractive. Women, in particular, have increased their dieting and exercise behavior in an attempt to attain the contemporary ideal of being thin and physically fit (Wilfrey & Rodin, 1995). In the present study, dieters were characterized by a higher mean BMI and a higher mean score for the EAT dieting subscale. The greater reliance by dieters on three of the four dietary behaviors associated with selecting

diets low in fat is consistent with results obtained by Tuschl et al. (1990) who reported that restrained eaters consumed diets with a lower percentage of the total calories from fat. Contento et al. (1995) reported that adolescent dieters had less fat in their diets and were significantly more likely than non-dieters to want their foods not to be fattening. Dieters in the present study also had significantly higher scores on four of the EDI subscales (drive for thinness, bulimia, body dissatisfaction, interoceptive awareness). French et al. (1995a) suggested that dieting may be a direct causal antecedent of negative psychological changes and reported that body dissatisfaction and drive for thinness significantly increased over a 3-year period among frequent dieters. The lack of a significant difference in self-esteem between dieters and non-dieters reported herein is in contrast to findings from previous studies which indicated lower self-esteem among dieters (French et al., 1995b; Moore, 1993). In this study, fat avoidance behaviors were not related to BMI in either sex. However, dieting-related behaviors, as assessed by the dieting subscale of the EAT, and drive for thinness, were associated with fat avoidance in both sexes. These findings support the assertion that both female and male dieters employ some combination of the fat avoidance behaviors (i.e. modifying meat, avoiding fat, fat substitution, fat replacement) assessed in this study. In females, greater reliance on fat avoidance behaviors was also related to lower self-esteem and higher scores on the body dissatisfaction, bulimia, ineffectiveness, interpersonal distrust, and interoceptive awareness subscales of the EDI. These associations suggest that fat avoidance may be a predictor of eating pathology

Dietary fat reduction

and/or psychosocial problems in college-aged women. An additional interpretation is that female undergraduates with an eating pathology are likely to avoid dietary fat. Similar results were reported from a sample of female undergraduate students at a major midwestern university. Here, eating pathology was associated with the consumption of diets providing  20% of energy from fat (Rock et al., 1996). In light of the overconsumption of fat in many westernized cultures, an individual's willingness to adopt dietary fat avoidance practices is typically perceived as positive. For example, Devine & Sandstrom (1996) reported that among employed women aged 30±60 year, fat avoidance scores were lower among those who perceived many barriers to healthful eating. In this assessment of the relationship of social roles and nutrition beliefs to fat avoidance practices, there is an inherent assumption that fat avoidance is desirable and consistent with improved health. The present finding of a relationship between fat avoidance scores and subscale scores indicative of higher levels of eating pathology and/or psychosocial problems appears to be at odds with conventional wisdom. However, college-aged women are likely to represent a unique population in this regard, a group characterized by a high prevalence of dieting and disordered eating and for whom fat avoidance may be primarily related to negative factors such as poor body image and low self-esteem. Also of interest was the finding of an association between fat avoidance and perfectionism scores in males but not in females. However, the overall significance of this relationship is unclear and awaits confirmation from future investigations. In summary, study participants were classified as dieters on the basis of having dieted during the 12 month period preceding the study with the express purpose of losing weight. Both male and female dieters were characterized by a greater reliance on modifying meat to reduce fat and on avoiding fat as a seasoning whereas female, but not male, dieters indicated a greater likelihood of substituting high-fat foods with specially manufactured lower-fat foods and of replacing high-fat foods with low-fat alternatives. Although many nutrition-related recommendations remain controversial, there is a general consensus among health and nutrition professionals that lowering dietary fat is an appropriate goal for most Americans. In recent years, the food industry has introduced a variety of low-fat or no-fat foods designed to help the consumer achieve a reduction in fat intake. In light of evidence from a variety of sources that dietary fat can play a key role in the etiology of obesity (Ravussin & Tataranni, 1997), it is not surprising that dieters relied heavily on the dietary fat reduction behaviors assessed in this

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study. Of particular interest is the finding that females in general, and female dieters in particular, relied on these behaviors to a greater extent than did males. This is consistent with the previously made assertion that women, more so than men, have increased their dieting and exercise behavior in an attempt to attain the contemporary ideal of being thin and physically fit (Wilfrey & Rodin, 1995). In the present study, female participants appeared to focus on dietary fat reduction as a method to reduce caloric intakes. However, since specific dietary intakes were not assessed, it is unclear whether these dietary fat reduction behaviors actually led to a reduction in dietary fat. Finally, the results indicated that, in females, a greater degree of fat avoidance was associated with significantly lower levels of self-esteem and higher scores on the EAT and on six of the eight EDI subscales. These data suggest that fat avoidance may be a predictor of eating pathology and/or psychosocial problems in college-aged women. If this is indeed the case, these factors may become mutually reinforcing, thus making positive change or modification of behaviors more difficult, and necessitating a more holistic approach to the treatment of eating disorders.

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