Dietary guidance for obese children and their families using a model nutritional balance chart

Authors


Atsuko Satoh, Akita Nursing and Welfare University, 2-3-4, Shimizu, Oodate, Akita 017-0046, Japan. Email: a-satoh@well.ac.jp

Abstract

Aim:  Childhood obesity has been described as a public health disaster. Nutritional balance is surely one of the key factors to reduce obesity, but successful nutritional education has not been reported yet. In the present study, an easily handled model nutritional balance chart (MNBC) for obese children and their families was investigated.

Methods:  Twenty-one children received dietary guidance using the MNBC once per month for 6 months. Eight control children did not receive dietary guidance but cooperated in providing data once per month. The effectiveness of the program was judged by changes in nutritional balance, percentage overweight values based on age- and sex-specific standard body weights for height, and responses to questionnaires.

Results:  The percentage overweight values significantly decreased after 6 months for the intervention group, while the percentage overweight values for the eight control children showed a tendency to increase. Improvement in the nutritional balance was observed for sugar and beans. Most children using the MNBC described paying more attention to their nutritional balance than before.

Conclusion:  Our guidance method seems to be useful for obese children and their families.

INTRODUCTION

The nationwide statistics for the physical development of Japanese children by The Ministry of Education, Culture, Sports, Science and Technology revealed that the prevalence of obesity in school children increased two-fold (from 5% to 10%) in the last 20 years (The Ministry of Education, Culture, Sports, Science and Technology, 1990). The data available from surveys of young people aged 5–17 years, collated for the World Health Organization’s (WHO’s) Global Burden of Disease report, reflects a wide range of prevalence levels, with the prevalence of overweight children in Africa and Asia averaging well below 10%, but in the Americas and Europe, at >20% (Lobstein, Baur & Uauy, 2004). It has been suggested that obesity is second only to smoking as a preventable cause of death. Childhood obesity is thought to be related to a higher risk of developing lifestyle-related diseases, such as ischemic heart disease, hyperlipidemia, and diabetes (Freedman, Khan, Dietz, Srinivasan & Berenson, 2001).

There have been a number of reports on interventions to reduce obesity in children: increasing physical activity, decreasing television-viewing, and healthy dietary habits, or a combination of them. Caregivers directly determine a child’s lifestyle, environment, and body weight through food selection, home eating patterns, meal structure, responsiveness to a child’s feeding cues, and general parenting style (Golan & Crow, 2004). Dietary guidance methods for obese children and their families have been developed, including group programs such as summer camps (Di Pietro et al., 2004), childhood obesity workshops (Pietrobelli, Flodmark, Lissau, Moreno & Widhalm, 2005), individual family programs such as the meal-recording method (Brady, Lindquist, Herd & Goran, 2000) and the Food Guide Pyramid method (Goldberg et al., 2004). However, nutritional education for healthy dietary habits generally has not been successful. The expansion of fast food restaurants and take-home food industries might contribute to a breakdown in dietary habits, including the excessive intake of fats and sugars. Changing ingrained dietary habits is not easy and it is apparent that, as a preventive measure for obesity, the family must be involved in any dietary guidance program.

In the present study, in order to enable children and their families to learn to adjust their nutritional balance and to control energy intake, we investigated a simple guidance method, the model nutritional balance chart (MNBC). The MNBC demonstrates the ideal dietary distribution of 11 categories of food. The number of times each food category was consumed was marked with black dots, but not by amount. This method shows where the children’s choices were made through visual confirmation. With guidance and recommendations provided to the subjects regarding any unbalances, there was a subsequent adjustment of the nutritional balance of foods consumed by the subject. In order to investigate the effectiveness of the nutritional effect, other factors such as exercise or television-viewing were not controlled.

METHODS

The study subjects for the present study were recruited from the pediatric clinics of the three hospitals in Oodate city, Akita Prefecture, Japan, where the authors had clinical assignments. The criteria for inclusion to the multicenter study were obesity and ages from 8–14 years. According to the criteria for obesity in childhood adopted by The Ministry of Health, Labor and Welfare in Japan, a child was considered to be obese when the body weight exceeded 120% of the standard body weight, which is defined as the mean body weight corresponding to the height for that age and sex obtained from national statistics for Japanese school children in 1990 (The Ministry of Education, Culture, Sports, Science and Technology, 1990). The subjects of the present study had no endocrine, metabolic or kidney disease. Blood was drawn after an overnight fast and the subjects underwent anthropometric measurement of their height and body weight. The data on the blood were provided by the clinical laboratory in each hospital.

Among the 43 obese children, 29 were randomly chosen for the obesity intervention groups and the other 14 children comprised the control group. Three children in the intervention group refused to participate in the study and five children in the intervention group withdrew after 1 month of intervention, leaving 21 remaining children in the intervention group. Among the 14 children in the control group, six children refused to participate in the study, leaving eight remaining children in the control group. These two groups were stable during the entire length of the study. Before starting dietary guidance, both the intervention and control subjects and their parents received conventional dietary guidance from nutritionists at the hospitals. The intervention group was subsequently under the charge of the authors for the long-term, present intervention, while the control group participants and their parents subsequently received conventional dietary guidance once per month, such as the restriction of kilojoules and nutritional balance of carbohydrates, proteins, and fat by the nutritionists at the hospitals. All of the subjects continued in the program for 6 months. The control group of eight subjects did not receive the present dietary guidance, but cooperated in providing data.

All the participants, including their parents, completed a questionnaire about physical characteristics, health assessment, lifestyles, family composition, and eating habits. The physical characteristics and physical examination, including peripheral blood examinations, are listed in Table 1. The average age in the intervention group was 11.0 ± 1.5 years (mean ± SD), ranging from the second grade in primary school (age = 8 years) to the second year in junior high school (age = 13 years). The ratio of females to males was 11:10. The average age of the control group was 12.4 ± 1.6 years, ranging from fourth grade in primary school (age = 10 years) to the third year in junior high school (age = 14 years). The ratio of females to males was 6:2. The study protocol adhered to the Recommendations of the Declaration of Helsinki for Human Experimentation (World Medical Association, 2000), verbal informed consent was obtained, and subject anonymity was preserved by the use of a coding system. Ethical approval was obtained from the Ethical Committee of Akita Nursing and Welfare University.

Table 1.  Blood examinations and physical characteristics
ExaminationGroupP
InterventionControl
  • *, **

    show significance at P < 0.05 and P < 0.01 between the pre- and post-interventions using two-sided Wilcoxon’s signed rank test, respectively. The values are the mean ± SD. HDL-C, high density lipoprotein cholesterol; LDL-C, low density lipoprotein cholesterol; NS, no significance between the intervention and control groups by two-sided Mann–Whitney’s U-test.

Sex (female/male)11/10 6/2 
Age (years)11.0 ± 1.512.4 ± 1.6 
Fatty liver (N) 2 0 
Pre-intervention
 Blood examination
  Total cholesterol (mg/dL)184 ± 27174 ± 24NS
  Triglyceride (mg/dL)118 ± 67 86 ± 26NS
  LDL-C (mg/dL)101 ± 21125 ± 14NS
  HDL-C (mg/dL) 58 ± 11 51 ± 12NS
  Serum glucose (mg/dL) 83 ± 10 89 ± 5NS
  Serum protein (g/dL) 7.2 ± 0.6 7.4 ± 0.3NS
  Hemoglobin (g/dL)14.1 ± 0.713.0 ± 0.6NS
 Percentage overweight (%)
  Overall 50 ± 22 49 ± 16NS
  Female 58 ± 26 46 ± 15NS
Post-intervention
 Blood examination
  Total cholesterol (mg/dL)169 ± 33189 ± 32NS
  Triglyceride (mg/dL)112 ± 50 69 ± 14NS
  LDL-C (mg/dL)103 ± 19130 ± 19NS
  HDL-C (mg/dL) 58 ± 11 56 ± 17NS
  Serum glucose (mg/dL) 80 ± 11 88 ± 5NS
  Serum protein (g/dL) 7.3 ± 0.5 7.4 ± 0.7NS
  Hemoglobin (g/dL)14.5 ± 0.813.5 ± 0.6NS
 Percentage overweight(%)
  Overall 42 ± 21** 50 ± 18NS
  Female 48 ± 21* 47 ± 18NS

The MNBC was designed to outline a 6697 kJ intake according to the recommendation by the Japan Obesity Society (Japan Obesity Society, 2001). The MNBC demonstrates the ideal dietary distribution of 11 categories of food: meat, fish, eggs, milk and dairy products (hereinafter called milk), beans and bean products, such as bean curd and miso soup (hereinafter called beans), green and yellow vegetables, light-colored vegetables, fruit, potatoes and grains (hereinafter called grains), oil, and sugar (Table 2). The number of times each food category was consumed was marked with black dots; the foods eaten were recorded by category, but not by amount. The MNBC includes food for 3 days.

Table 2.  Model nutritional balance chart for 3 days
MealMeatFishEggsMilkBeansGreen and yellow vegetablesLight-colored vegetablesFruitGrainsOilSugar
Breakfast••••• 
  ••  
    ••   
     ••    
Snacks between-meal
Lunch••••• 
  ••••  
     ••  
     ••   
Snacks between-meal      ••  
         
Dinner •••••• 
  ••••• 
   •••••  
    •••••   
Snacks between-meal

The pre-intervention period, before the subjects received dietary guidance, was 1 month and the postintervention period was 6 months. After finishing the post-intervention period, we followed up changes in height and body weight for 6 months. It took 2 years of serial participation by the subjects, from August 2003 to July 2005. The intervention method consisted of four steps performed once per month: (i) The investigator mailed the meal chart to the child (and/or mother). The meal chart consisted of columns for breakfast, lunch, dinner, and snacks between meals. The meal chart was to be filled out for 3 days of the last week of each month: Friday (when the school lunch is eaten), Saturday (when school is not held and the school lunch is not eaten, but when many children attend cram schools or private lessons), and Sunday (when school is not held and the school lunch is not eaten). The subjects were instructed to record the name of each food eaten on the meal chart; (ii) the child (and/or mother) completed a meal chart based on a 24 h recall and mailed it to the investigators; (iii) the investigators placed black dots on the nutritional balance chart according to the content of the meal chart. Each time any food was consumed, one black dot was placed on the nutritional balance chart in the corresponding section. We compared the distribution of food for each menu plan in Table 2 to the food actually eaten. Foods cooked at home, as well as commercially available, prepared food, were converted from the food exchange list published by the Japan Diabetes Society (Japan Diabetes Society, 1998). The nutritional balance chart was mailed to the child (and/or mother) within 1 week after receiving the meal chart, providing guidance and recommendations to the subjects regarding any unbalances; and (iv) the child (and/or mother) looked at the nutritional balance chart, noting any imbalances, and mailed their comments and impressions to the investigators. The investigator responded with advice, comments, and encouragement to the child (and/or mother), which was then mailed together with the meal chart for the next month.

We calculated the nutritional balance, as follows: (the actual food intake [black dots]÷ the ideal food intake following the MNBC [black dots]). Thus, the nutritional balance based on the MNBC was ideally “1”. The use of Body Mass Index (BMI) cut-off points of 25 and 30 to define adult overweight and obesity, respectively, has been recommended by the WHO, but, for children, their BMI will normally change with age and vary by gender (Lobstein et al., 2004). Furthermore, the populations used to define the criteria did not include Japanese children. We therefore used percentage overweight values, defined as the fractional difference of actual weight to age and sex-matched standards derived from nationwide surveys of Japanese children (The Ministry of Education, Culture, Sports, Science and Technology, 1990). Two-sided Wilcoxon’s signed rank test was performed between the percentage overweight values pre-intervention and postintervention and between postintervention and 6 months after finishing the intervention. The blood examinations were statistically calculated using two-sided Mann–Whitney’s U-test. The two-sided Wilcoxon’s signed rank test was used for the significance in the food intake data. In all the items, statistical significance was considered for P-values <0.05.

RESULTS

A medical check revealed no diseases in any of the children, except for two children with fatty liver in the intervention group. The peripheral blood results at entry to the study were within the upper limits of normal for the total cholesterol, serum glucose, serum protein, serum triglyceride, and hemoglobin (Table 1). The intake ratios of food before and 6 months later in the intervention group are shown in Table 3. The pre-intervention nutritional intake was high in eggs, grains, oil, and sugar, and low in fish, milk, beans, green and yellow vegetables, light-colored vegetables, and fruit. Six months later, the figures approached the “1” of the MNBC in some categories. Significant increases in nutritional balance were observed for beans (P < 0.05) and significant decreases were observed for sugar (P < 0.05) (Table 3). The time courses in relation to the nutritional balance for beans and sugar are shown in Figure 1. The intake of sugar decreased rapidly at 1 month after intervention and the intake of beans increased gradually to 1.

Table 3.  Intake ratio of food before and 6 months later in the intervention group
TimeMeatFishEggsMilkBeansGreen and yellow vegetablesLight-colored vegetablesFruitGrainsOilSugar
  • *

    P < 0.05; NS, no significance. The values are the mean ± SD.

Before intervention1.0 ± 0.40.6 ± 0.51.4 ± 0.80.6 ± 0.50.8 ± 0.50.3 ± 0.20.4 ± 0.20.9 ± 0.91.5 ± 0.41.4 ± 0.51.3 ± 0.9
Six months later0.9 ± 0.30.7 ± 0.41.1 ± 0.60.4 ± 0.30.9 ± 0.60.3 ± 0.10.5 ± 0.20.7 ± 0.71.6 ± 0.31.2 ± 0.40.8 ± 0.6
SignificanceNSNSNSNS*NSNSNSNSNS*
Figure 1.

Changes in the intake ratios of food before and following 6 months of intervention. The significance was plotted compared with the baseline values for sugar and beans (*P < 0.05). (●) intake of sugar; (○) intake of beans.

Individual changes in the percentage overweight values in the intervention and control groups are shown in Figure 2. Before intervention, the percentage overweight value in the intervention group was 50 ± 22% (mean ± SD); after 6 months, it was 42 ± 21% (P < 0.01) (Fig. 2a). After finishing the guidance period, we were able to follow up for 6 months on the 15 subjects in the intervention group. The percentage overweight values in those 15 subjects were 46 ± 18% pre-intervention and 38 ± 17% post-intervention (P < 0.01) and they decreased further after finishing the guidance period, to 34 ± 16% (P < 0.05) (Fig. 2b). The overall decrease in the percentage overweight value from pre-intervention to that after finishing the guidance period was significant (P < 0.01).

Figure 2.

Individual changes in the percentage overweight values before and after the intervention in the (a) intervention group and the (c) control group. After finishing the intervention period, the 15 subjects in the intervention group (b) and the eight control subjects (c) had their percentage overweight values followed for 6 months. (□) and bars, the mean ± SD; (○–––○) female; (●––●) male.

Of the eight subjects in the control group, the percentage overweight value increased slightly from pre-intervention (49 ± 16%) to after 6 months (50 ± 18%) (no significance) (Fig. 2c). In addition, there was a further slight increase during the 6 months after the conclusion of the guidance period, from 50 ± 18% to 52 ± 27% (no significance). The percentage overweight value in the female subjects in the intervention group (n = 11) was 58 ± 26% before intervention and 48 ± 21% after intervention (P < 0.05), while that of the female subjects in the control group (n = 6) was 46 ± 6% before intervention and 47 ± 8% after the guidance period (no significance) (Table 1).

After finishing the intervention guidance, impressions of the study were elicited from 17 subjects. All reported that they had become more careful about their nutritional balance. In addition, 16 subjects reported that the MNBC was easy to read and to understand, although 14 subjects reported that filling out the meal chart was a burdensome chore. Increased conversation with the mothers (and/or children) was reported by 12 subjects, increased physical activity by 11 subjects, and a lighter body sensation by 10 subjects.

DISCUSSION

Conventionally, food intake has been calculated through meal recording and the weighing of food and a nutritionist would give dietary guidance. However, although the food-weighing method gives a relatively accurate grasp of the energy intake, it is also a very onerous chore that is not suited to children (and/or mothers). Also, in recent years, the expansion of restaurants and take-home, prepared food industries has made it difficult to determine how many kilojoules are in a particular food. Lifestyle patterns that lead to a breakdown in nutritional balance might involve spending a large portion of time at home engaged in watching television programs or playing video games. In addition, because many mothers use prepared, heat-and-serve pouch and instant foods, a lack of vegetable intake was seen. The continued prevalence of pediatric obesity has been reported to be contradictory.

Physical education in schools and reduced television viewing are two examples of interventions that have been successful (Doak, Visscher, Renders & Seidell, 2006). It is possible to prevent obesity in children through limited, school-based programs that combine the promotion of healthy dietary habits and physical activity (Flodmark, Marcus & Britton, 2006). Togashi et al. (2002) reported that, in achieving normal body weight in adulthood, the adults’ dietary and exercise habits had changed after childhood obesity treatments with parental involvement. Epstein, Valoski, Wing and McCurley (1990) evaluated the effects of a family-based, long-term behavioral treatment for obese children on young adults’ body weight over 10 years and they concluded that the treatment was effective in improving their relative weight 10 years later. However, no differences were found between the intervention and control groups in most studies, although the interventions did not have a negative effect in any of the studies (Lobstein et al., 2004). Losing weight over the short term, but then experiencing a rebound gain in weight, remains the usual experience for the majority of obese children and adolescents (Lobstein & Dibb, 2005). Lake, Power and Cole (1997) reported that the children of obese parents are several times more likely to develop adult obesity than the children of parents with a normal body weight. Among the visual guidance methods that put the focus on nutritional balance, the Food Pyramid Method is the most prevalent in the USA (Goldberg et al., 2004). In the present study, through the repetitive action of comparing the dietary balance and the MNBC each month, the subjects learned to be aware of imbalances in their diets and to control their energy intake. The present method is a simple dietary guide for obese children and their mothers.

A significant improvement was seen for sugar and bean intake. We thought that the percentage overweight values were brought about by the intake of sugar, which is easily turned into energy. Although there was a slight improvement in the intake of green and yellow vegetables and light-colored vegetables, the intake was still low at only 0.3 and 0.6 of the MNBC, respectively. Advising an increase in the intake of vegetables and especially bringing sugar closer to the MNBC ideal appears to be the key point in bringing about an improvement in obesity.

There are many limitations in the present study: (i) A small number of subjects might lead to false-positive conclusions. The subjects choosing to participate in the present study might bias the positive results. The present method must thus be viewed as a pilot study in the control of obesity; (ii) in the control group, there were more females than males. The obesity level of girls of this age has particular characteristics. However, the percentage overweight values of the females in the intervention group were similar to the overall group. Therefore, we pooled the percentage overweight values of both the females and males; and (iii) we did not control for sedentary activity compared to physical activity. The lack of an association between the intervention of physical activity and nutrition was reported by Prochaska and Sallis (2004). They suggested that, rather than changing the behaviors in concert, the participants might opt to focus on only one behavioral target. In the present intervention group, some described a lighter body sensation, which might increase physical activity. Finally, the participants were responsible for reporting their own food intake by category but not by the amount of food, which precludes any quantitative estimate of their actual food intake. Importantly, however, our method is a simple way to visually educate the child regarding good nutritional habits.

Caldwell, Nestle and Rogers (1998) and Harrell, Davy, Stewart and King (2005) have pointed out the importance of dietary education in school. However, in actual practise, it is very difficult to obtain adequate time in the school setting to give guidance (Moyers, Bugle & Jackson, 2005). After finishing the intervention, the intervention percentage overweight values continued to decrease, which suggests that the present method might be more long-lasting compared with the conventional educational treatment. Food intake is a very complex phenomenon, with both rational and habitual components. The present method might be one way to modify habits and customs through the rational use of the MNBC. Computerized analysis of the meal chart from the subjects referring to the MNBC might reduce the turnaround time and accelerate the application of the present method to a large number of subjects in the future.

ACKNOWLEDGMENTS

We thank Dr James P. Butler, physiology program, School of Public Health, Harvard University, Boston, USA, for his editorial guidance in preparing this manuscript.

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