Food Practices and Concerns of Teenage Girls

Food Practices and Concerns of Teenage Girls

written for the National Institute of Nutrition by Gwen Chapman, Ph.D.

Despite a general improvement in nutrition knowledge of teenage girls in the past three decades, interventions directed toward this group have not resulted in improved eating habits.^1-4 Surveys consistently show that in North America teenage girls consume excess fat and less than the Recommended Nutrient Intake (RNI) for some micronutrients^5-11 In addition, the increasing prevalence of obesity and eating disorders in this population is a concern.^3,6 The difficulty in changing teenagers' eating habits may be related to inadequate consideration of issues that they consider important. The nutritional adequacy of teenage girls' diets and their perspectives on food and its relevance in their lives is the focus of this review.

The Teenage World

Teenage girls experience a variety of transformations. The increased proportion of body fat in early adolescence leads to a rise in preoccupation with body image. Mid-adolescence is associated with assertion of independence, when peer groups dominate social life and risk behaviours increase. Late adolescence may bring uncertainties about sexuality, future relationships and career options.¹²

Having a part-time job, spending more time away from home, dating and getting a driver's licence are examples of significant lifestyle changes that can affect eating habits. Even the availability of balanced meals at home does not guarantee they will be eaten. Teenagers' food choices also can be influenced by social pressures to achieve cultural ideals of thinness or athletic prowess, gain peer acceptance or assert independence from parental authority. Young women seem especially vulnerable to pressures from advertising and to frequent promotion of low nutrient density foods on television.¹⁴

What Do They Eat?

Despite the lack of information about the nutritional status of Canadian teenagers, they likely represent a healthy segment of the population. In Ontario, more than half of 12 to 19 year-olds were free of even minor health problems.¹⁵

The self-reported dietary intakes of teenage girls range from 1850 kcal/d to 2200 kcal/d. ^7-11 In comparison, the RNI is 2200 kcal/d and 2100 kcal/d for 10- to 15- and 16- to 18- year-old females, respectively. ¹⁶ Surveys showing a mean energy intake less than the RNI ^7,9,10 found no evidence of low body weights, suggesting low levels of activity among girls or under-reported intake. Other surveys also show that their activity levels decline dramatically in adolescence.^13,17 In Ontario, one third are only involved in some form of physical activity no more than twice weekly.¹⁵ In British Columbia, the proportion of female students who exercised less than three times per week increased steadily throughout adolescence, from 24% in Grade 8 to 61% in Grade 12.¹⁷ These low activity levels have raised concerns about adolescent obesity. The prevalence of this problem is difficult to assess because criteria defining obesity in this group have not been standardized.¹⁸ However, comparison of cross-sectional data collected over the past three decades indicates substantial increases in the levels of overweight among North American teenagers.^19-21

The difficulty for teenage girls to meet the RNI with a low energy intake is especially apparent for iron and calcium. Between 29% and 84% of young Canadian women may not meet the RNI for iron^8,10,11 , and between 34% and 65% may consume less calcium than recommended.^{7-10, 22} The predicted prevalence for inadequate calcium intakes ranges from 20% to 24%^8,10 . However, the actual prevalence may be higher as the RNI for calcium may be inadequate.²³ Fewer girls would have low micronutrient intakes if they ate enough food to meet the RNI for energy, without changing their dietary composition.

The energy distribution of the average teenage girl's diet is approximately 15% protein, 50% carbohydrate and 35% fat.^7,9 In Ontario, 44% of 12- to 19- year-old girls report more than 38% of their total dietary intake as fat, and 78% consume less than 55% of their energy as carbohydrate.¹⁵ It is recommended that during early adolescence, an energy intake adequate to sustain growth be emphasized with a gradual lowering of fat intake.²⁴ Once linear growth has stopped, fat intake should be limited to 30% of energy and at least 55% of energy should come from carbohydrate.¹⁶

Although low iron intakes could have a relatively immediate negative effect, resulting in iron deficiency, the consequences of low calcium and high fat intakes would not be apparent for years. Recent evidence suggests that a low calcium intake may be a serious problem because it can result in decreased peak bone mass in early adulthood, increasing the risk for development of osteoporosis.^25-27 High fat and low carbohydrate intakes during adolescence are thought to increase the future risk of cardiovascular disease and perhaps some types of cancer.^3,6,18

What is Their Relationship with Food?

Three interrelated themes have emerged from studies of teenagers' food habits.

"Healthy" or "Junk" Foods
Girls tend to classify foods as either "healthy" (i.e., good) or "junk" (i.e., bad).^4,28-31 "Healthy" foods, of which fresh fruit and vegetables are their most cited examples, are described as low in calories, sugar, fat, cholesterol, salt, additives, preservatives and artificial ingredients, and as sources of vitamins, minerals and proteins. "Junk" foods such as chocolate bars and potato chips are described as having the opposite profile, and are valued because they taste good and are convenient.^4,28,30 Poor health is only one of several negative consequences of "junk" food consumption they name. More frequently mentioned are weight gain, acne, bad mood, laziness and cavities.^28,29

"Junk" food is associated with snacks, friends, being away from home, independence and having fun. However, conflict is apparent as these foods also have the negative connotations of going off a diet, being out of control, overeating and feeling guilty. "Healthy" food is associated with family, home and meals, being on a diet, being concerned with weight and appearance, self-control and being good. Overall, girls' categorization of foods as "junk" or "healthy" appears to have more to do with social issues and concerns with weight and body image than with health issues.³⁰

Weight Concerns and Body Image
These connotations of "junk" and "healthy" foods reflect how teenage girls' insecurity about their bodies affects their thoughts about food. Although most Canadian girls fall within the healthy weight range, many do not believe their weight is appropriate. More than 80% of teenage girls surveyed in British Columbia reported a healthy body weight for their height, but less than 50% saw their weight as "about right". The proportion seeing themselves as overweight increased from 38% in Grade 8 to 51% in Grade 11.¹⁷ The proportion who wanted to lose weight increased from 69% in Grade 7 to 82% in Grade 12.¹⁷ Another Canadian study showed 74% of those between 15 and 19 years of age would like to lose weight.³² U.S. and U.K. studies show similar findings, indicating that between 40% and 66% of teenage girls perceive themselves as being too heavy even though less than 15% would be considered obese using objective criteria.^33-36 A U.S. study found that 81% of female high school students wanted to lose, including 49% of underweight girls.³⁶

For many young women, weight and eating concerns extend beyond dissatisfaction with their current body to include worrying about gaining weight or becoming fat.^29,33,34,36 In one study, more than 30% of the 9-year-old girls expressed fear of fatness. This fear increases with age, reaching over 80% among 18 year-olds.³⁴

Thus, it is not surprising that most teenage girls have dieted at some time.^35-37 Fortunately, evidence shows that many young Canadians take a common-sense approach in their weight control strategies. In one study, 35% of 15- to 19- year-old girls were trying to lose weight. Cited as the best ways to lose weight were: being more active (85%), eating a balanced diet (53%), and eating less food (21%).³⁸ Of the young women studied in British Columbia, over 50% were trying to lose weight. Exercise was their most common strategy (46%), followed by exercise and diet together (30%), then diet alone (13%).¹⁷ A Toronto study reported that teenage girls dismissed fad diets as "stupid", unhealthy and ineffective, and advocated increased exercise and "watching what you eat" by eating "healthy" foods and reducing or eliminating "junk" foods.²⁹

Girls' weight and dieting concerns are linked more strongly to social and psychological issues than to physical health matters. Cross-sectional studies have shown weight and eating concerns to correlate with decreased self-esteem and increased depression.^39,40 Participants in qualitative studies thought that looking good, which means having an appropriate body size, is important to attracting boyfriends.^4,29 In another study, where teenage girls were asked to give one or more reasons for dieting, 95% listed cosmetic reasons while only 25% gave health-related reasons.³⁶

Food Preferences and Eating Habits
Food preferences and taste appear to be key in determining their food habits. In one study, girls used the statement "don't eat" interchangeably with "don't like", and "I eat" seemed to be synonymous with "I like".²⁹ Other studies have shown relatively strong correlations between consumption of specific foods and perceived taste.^22,41,42 Although much individual variation exists in food preferences, teens tend to prefer the taste of many "junk" foods, and dislike many "healthy" foods. Most of the girls in one study²⁹ agreed that they disliked most cooked vegetables and organ meats, and most took it for granted that "everyone" likes "junk" foods.

Implications for Nutrition Interventions

To be successful, any nutrition intervention must incorporate fundamental health promotion principles.^43,44 Programs developed specifically for young women must consider issues that are important to them, seek their input, and include strategies directed toward these girls and their environment.

Youths participating in health promotion efforts have often been passive recipients of adult efforts. When asked what they think, youths report overwhelmingly the desire for participation and involvement.⁴⁵

Within an empowerment model of health promotion, it is important to acknowledge and accept as valid the views of youths and, perhaps, to use them to broaden the understanding of how food and health are linked. Teenagers identify different health priorities than health professionals. They tend to care more about relationships and appearance, while nutritionists focus on nutritional adequacies.

Health promotion programs should address the myriad factors affecting food choices, including body image, healthy eating choices, social pressures and busy, stressful lifestyles. Although teenage girls require guidance and support, it is important not to force adult behaviours on them, instead allowing them to "be adolescents".¹² An environment of trust must be created before presenting (not preaching) the facts and options, which lets them form their own conclusions.

Some programs directed toward teenage girls could provide background information, skills and opportunities to make better food choices, and assist them to develop healthier behaviours and become less vulnerable to food myths and false promises from advertising.

Programs aiming to reduce fat intake, or increase calcium and iron intake, should not be based solely on risks of developing heart disease, osteoporosis or anemia, as these problems may be too far removed to be motivating.⁴⁶ Focusing on vitality and bone and muscle strength might better reinforce positive behaviour.

Current standards for the female body could be discussed and challenged, helping young women to feel comfortable with a wider variety of body shapes and sizes, and to dissociate issues of attractiveness, self-esteem and success.

Nutrition education programs could also challenge young women's understanding of foods as either "healthy" or "junk", and the feelings and associations that go along with each. As part of the diet of an active teenager, fun foods and convenience foods are not necessarily fattening or unhealthy. Discussion of the "Other Foods" category of Canada's Food Guide to Healthy Eating may be a useful way of approaching this issue.

Without a supportive environment, awareness of the issues will not lead to an improvement in teenage girls' nutritional well-being. As long as they live in an environment that dictates women must be thin and, at the same time, encourages the consumption of both diet products and high fat, high energy, low nutrient density foods, teenage girls will have difficulty feeling comfortable with food, their bodies and themselves. Social marketing techniques could be used to increase acceptance of people with a wider variety of body shapes and sizes, or to promote the role of fun foods and fast foods as a part of a healthy diet. It is essential to increase the availability of convenient, tasty, affordable foods of appropriate nutrient density, and to provide more opportunities for girls to become involved in physical activity, particularly of the kind that can be sustained after leaving school.¹³

Conclusions

Diet surveys indicate that, although many teenage girls have adequate intakes of most nutrients, calcium, iron and energy intakes tend to be lower and fat intakes higher than recommended. This eating pattern, coupled with low levels of physical activity, could put some girls at increased risk for development of osteoporosis, anemia, obesity and cardiovascular disease.

Teenage girls' concerns about their eating habits tend to focus on the interrelationships between their food preferences, their beliefs about foods as either "healthy" or "junk", and their concerns about weight and body image. Issues of social and psychological well-being, rather than physical health, are their main concerns.

Nutrition intervention programs for this population should integrate problems of dietary adequacy with those identified by teenage girls, and should include strategies aimed at both individual and environmental levels. In addition, further research is needed to increase understanding of their food issues and to evaluate the effectiveness of different intervention programs.

References

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This review was written for the NIN by Gwen Chapman, Ph.D., School of Family and Nutritional Sciences, The University of British Columbia.

NIN gratefully acknowledges the contributions of Rena Mendelson, D.Sc., School of Nutrition, Consumer and Family Studies, Ryerson Polytechnic University; Stanley Zlotkin, M.D., Ph.D., F.R.C.P.(C), Department of Pediatrics and Nutritional Sciences, The Hospital for Sick Children; and the NIN Scientific Advisory Council in the preparation of this text.

This article first appeared in NIN REVIEW, No. 23, Fall 1994, published by the National Institute of Nutrition.

Posted by: National Institute of Nutrition, September 1996.