Israel Medical Association Journal

Background: Data regarding the validity of self-reported weight and height in adolescents are conflicting.

Objectives: To evaluate the validity of self-reported weight and height among 13–14 year old schoolchildren. 

Methods: We conducted a cross-sectional study of 517 schoolchildren aged 13–14 years and compared self-reported and measured weight and height by gender, population group, parental education and crowdedness.

Results: Females under-reported their weight on average by 0.79 ± 5.46 kg (P = 0.03), resulting in underestimation of the body mass index with borderline significance (mean difference 0.28 ± 2.26 kg/m², P = 0.06). Males over-reported their height on average by 0.75 ± 5.81 cm (P = 0.03). Children from less crowded homes (≤ 1 person per room) overestimated their height more than children from more crowded homes, resulting in a significant underestimation of BMI[1] (mean difference between reported BMI and measured values was 0.30 ± 2.36 kg/m², P = 0.04). Measured BMI was a significant predictor of the difference between self-reported and measured BMI, adjusted for gender, population group, parents' education, and crowdedness (β = -0.3, P < 0.0001). As a result of this reporting bias, only 54.9% of children with overweight and obesity (BMI ≥ 85th percentile) were classified correctly, while 6.3% of children were wrongly classified as overweight and obese. The largest difference in BMI was observed in obese females (4.40 ± 4.34) followed by overweight females (2.18 ± 1.95) and underweight females (-1.38 ± 1.75). Similar findings were observed for males, where the largest difference was found among obese males (2.83 ± 3.44).

Conclusions: Studies based on self-reported weight and height in adolescents may be biased. Attempts should be made to correct this bias, based on the available data for each population.

Background: In view of the rising prevalence of obesity, the identification of young adult populations at risk is important for the formulation of intervention and prevention programs.

Objectives: To assess demographic and behavioral factors associated with an increase in body mass index in young healthy adults and to identify the incidence of overweight/obesity in this population.

Methods: Data on anthropometric measures, demographic characteristics, and health behaviors were collected retrospectively for a representative sample of young Israeli adults (11,391 men, 11,280 women) on their release from military service (age 20–22 years) between 1989 and 2003. The incidence of overweight (BMI[1] < 25-< 30 kg/m²), incidence of obesity (BMI ≥ 30 kg/m²), and increase in BMI during military service were calculated.

Results: The average increase in BMI during military service was 1.11 kg/m² in males and 1.08 kg/m² in females. A greater increase was positively associated with low paternal education and smoking cessation, and negatively associated with high physical activity. Twelve percent of subjects with a normal BMI on recruitment became overweight, and 21.7% of overweight subjects became obese. On multivariate logistic regression analysis, a higher incidence of overweight was associated with low education level (in both the subject and his or her father) in both genders, and non-use of oral contraceptives and low level of physical activity in females.

Conclusions: BMI appears to increase significantly during early adulthood. Intervention programs should be targeted specifically at subjects with low education or who started smoking before age 18, and physical activity (especially among females) should be encouraged.

Background: It has been suggested that increased calcium intake plays a role in preventing obesity and promoting weight loss.

Objectives: To assess the association between calcium intake, body mass index and waist circumference in Israel.

Methods: MABAT is a cross-sectional survey based on a random sample of 3246 Israelis aged 25 to 64. Of the 3246 survey participants, height and weight measurements were recorded for 2782 (1371 men and 1411 women). These were divided into three groups according to their BMI[1] (group A ≤ 24.9, group B 25–29.9, and group C ≥ 30) and given a 24 hour food consumption recall questionnaire. Waist circumference was measured in 2601 participants (1760 men and 841 women) and was considered to be excessive if ≥102 cm for men or 88 cm for women.

Results: The mean calcium intake was 511.5 ± 301.8 mg for group A, 499.4 ± 283.7 mg for group B, and 464.7 ± 280.1 mg for group C (group A significantly differed from group C, P < 0.002). The mean daily milk consumption in group A was higher than in groups B and C (103.4 ± 147.5, 85.7 ± 122.25, and 84.5 ± 135.1 g, respectively; P < 0.01). There was no correlation between daily dietary calcium intake and waist circumference for men but women with a waist circumference below 88 cm consumed significantly more dietary calcium than those with a waist circumference ≥ 88 cm (P < 0.03).

Conclusions: The study confirms the inverse relationship between daily dietary calcium intake and obesity. This linkage relates to the intake of milk, but not to other dairy products.

Background: The prevalence of obesity among children and adolescents in the western world has increased dramatically.

Objective: To assess the efficiency of routine childhood obesity screening by primary physicians in the pediatric population in Israel and the utilization of health services by overweight children.

Methods: The electronic medical records of children aged 60–83 months registered in 39 pediatric primary care centers between January 2001 and October 2004 (n=21,799) were reviewed. Those in whom height and weight were documented during a clinic visit (index visit) were classified as overweight, at risk of overweight, and normal weight by body mass index percentiles. The number of visits to the pediatrician, laboratory tests and health care costs 12 months after the index visit were calculated.

Results: Anthropomorphic measurements were performed in 1556 of the 15,364 children (10.1%) who visited the clinic during the study period. Of these, 398 (25.6%) were overweight, 185 (11.9%) were at risk of overweight, and 973 (62.5%) were normal weight. Children in the first two groups visited the clinic slightly more often than the third group, but the differences was not statistically significant (P = 0.12), and had significantly more laboratory tests than the rest of the children visiting the clinics (P = 0.053). Health care costs were 6.6% higher for the overweight than the normal-weight children.

Conclusions: Electronic medical records are a useful tool for population-based health care assessments. Current screening for obesity in children during routine care in Israel is insufficient and additional education of community pediatricians in diagnosis and intervention is urgently needed.

Objective: To assess the prevalence of diabetes in an Arab community, the contribution of obesity to diabetes development, and the therapeutic potential of a preventive program.

Methods: Data were obtained from the medical files of diagnosed diabetes patients attending a primary care clinic in an Arab village in northern Israel.

Results: Type 2 diabetes was diagnosed in 323 patients of whom 63% were women. The prevalence of diabetes below age 65 years was significantly higher among women than men. Diabetic women were younger than men at diagnosis (48.27 vs. 59.52 respectively) and were found to have higher body mass index (34.35 vs. 30.04 respectively) at diagnosis. The age at diagnosis of diabetes was strongly correlated with BMI[1] (r = 0.97, P < 0.0001).

Conclusions: Women of Arab origin are at higher risk of developing type 2 diabetes compared to men. Obesity in women seems to be associated with higher diabetes risk as well as earlier appearance of the disease. Therefore, they will have the disease for longer and, consequently, a higher risk for complications.