Food insecurity, weight control practices and body mass index in adolescents

OBJECTIVE: We investigated whether experienced food insecurity was associated with weight control behaviour of adolescents. DESIGN: A national survey of 16-year-old students with the six-item food security scale, questions concerning intentions of trying to change weight, physical activity patterns, and measurement of height and weight. SETTING: Representative sample of 29 schools in Trinidad, West Indies. SUBJECTS: Data analysed for 1903 subjects including 1484 who were food-secure and 419 who were food-insecure. RESULTS: In the whole sample, food security status did not vary by body mass index (BMI) category. 'Trying to gain weight' and 'spending most free time in activities involving little physical effort' were each associated with lower BMI. 'Trying to gain weight' was more frequent in food-insecure subjects (135, 32%) than in food-secure subjects (369, 25%, P = 0.012). After adjustment for BMI, age, sex, ethnicity and socio-economic variables, the adjusted odds ratio (OR) of 'trying to gain weight' for food-insecure subjects was 1.39 (95% confidence interval (CI) 1.07-1.82, P = 0.014). Food-insecure subjects (197, 47%) were more likely than food-secure subjects (575, 39%) to report that most of their free time was spent doing things that involved little physical effort (P = 0.003). This association was not explained by adjustment for BMI, age, sex and ethnicity (OR = 1.41, 95% CI 1.13-1.76, P = 0.002) or additional socio-economic variables (OR = 1.27, 95% CI 1.02-1.57, P = 0.033). CONCLUSIONS: Adolescents who experience food insecurity are more likely to intend to gain weight but engage in less physical activity than food-secure subjects with the same BMI.     

Association of body mass index and dietary restraint with changes in eating behaviour throughout late childhood and early adolescence: a 5-year study

OBJECTIVES: To describe patterns of dietary behaviours specific to low quality snacking, fruit and vegetable, and fast food consumption during the transition from childhood to adolescence and to examine how these behaviours are associated with tendencies towards dietary restraint and the occurrence of overweight and obesity in mid-adolescence. DESIGN: A 5-year follow-up of self-reported eating. Hierarchical linear modelling was utilised to explore the relationship between dietary changes and body mass index (BMI) and dietary restraint while controlling for physical activity and smoking. SETTING: The sample was derived from students participating in the Quebec Heart Health Demonstration Project, and represents rural, suburban and inner city youths. SUBJECTS: A sample of 561 girls and 627 boys in the fourth, sixth, seventh and ninth grades. RESULTS: Overall the sample was characterised by a decrease in fruit and vegetable consumption and increase in low quality snacking, and a decrease in fast food consumption over the 5-year follow-up. Dietary restraint and BMI were found to be associated with dietary behaviour. Lower than average dietary restraint was associated with a lower frequency of fast food consumption and greater increase in low quality snacking over the 5-year period. Higher than average dietary restraint was associated with lesser frequency of low quality snacking at baseline. Having a BMI in the obese range was associated with more frequent fast food consumption in the fourth grade and a more rapid drop in fast food consumption across the 5-year period. CONCLUSIONS: Dietary behaviours are associated with the psychological construct dietary restraint and with weight status in this population of adolescents.     

The effects of suspended ‘red mud’ on mortality,body weight,and growth of the marine planktonic copepod,Calanus helgolandicus

The effect of ‘red mud’ at a dilution of 1:10⁵ to 1:10⁶ on growth, body weight and mortality of juvenile stages of the planktonic copepodCalanus helgolandicus were investigated. In the presence of phytoplanktonC. helgolandicus ingested large amounts of ‘red mud’. In comparison to control copepods growth of ‘red mud’ animals was delayed. Mortality of ‘red mud’ animals was 5 to 8 times higher than that of control animals. The dry body weight of C III, C v, and adults raised from N v/NVI on in ‘red mud’ was far lower than the dry weight of the control animals. All results show that ‘red mud’ at the above mentioned dilutions affects negatively juvenile stages and adults ofCalanus helgolandicus.     

The impact of body mass index and Western advertising and media on eating style, body image and nutrition transition among Jordanian women

OBJECTIVES: To identify the impact of body mass index (BMI) and Western advertising and media on the stage of the nutrition transition among Jordanian women, and to evaluate their impact on eating styles and body image. DESIGN: A randomised cross-sectional survey that included a variety of culturally measured Likert-type scales and body size images. In addition, BMI was calculated based on measured height and weight. SETTING: In the homes of the participants. The data were collected by female interviewers who worked for the Jordan Department of Statistics. SUBJECTS: The sample was based on a random and representative selection of 800 mostly urban Jordanian women. A pre-test sample of 100 women was also used to validate the instruments. RESULTS: Women tended to agree that they ate based on emotional cues. They had high levels of disordered eating attitudes and behaviours and 42.1% were considered restrained eaters. However, these women also had higher than expected body esteem levels and desired a healthy body size. As expected, being obese was associated with a desire to lose weight, being a restrained and emotional eater, and having more disordered eating attitudes and behaviours. Similarly, Western advertising and media were associated with restrained and emotional eating, desired weight loss, and disordered eating attitudes and behaviours. CONCLUSIONS: There is a need to develop health education materials that explain the influence of obesity on health and the negative psychological and physical consequences of restrained and emotional eating, building on the current cultural preferences of healthy body size. Further implications and suggestions for future research are discussed.     

The effect of drug abuse on body mass index in Hispanics with and without HIV infection

OBJECTIVE: There is a widely held view that the lower weight of drug abusers is attributable to diet. However, many studies on the dietary intake of drug abusers have failed to find energy insufficiency, while non-dietary factors have rarely been examined. The purpose of this study was to examine non-dietary factors that could affect the weight of drug abusers with and without HIV infection. DESIGN: Participants were recruited into one of three groups: HIV-positive drug abusers (n=85), HIV-negative drug abusers (n=102) and HIV-positive persons who do not use drugs ('non-drug abusers', n=98). Non-dietary factors influencing weight included infection with HIV and/or hepatitis, malabsorption, resting energy expenditure and physical activity. SETTING: The baseline data from a prospective cohort study of the role of drug abuse in HIV/AIDS weight loss conducted in Boston, USA. SUBJECTS: The first 286 participants to enroll in the study. RESULTS: HIV-positive drug abusers had a body mass index (BMI) that was significantly lower than that of HIV-positive non-drug abusers. The differences in weight were principally differences in fat. In the men, cocaine abuse, either alone or mixed with opiates, was associated with lower BMI, while strict opiate abuse was not. Infection with HIV or hepatitis, intestinal malabsorption, resting energy expenditure and physical activity, as measured in this study, did not explain the observed differences in weight and BMI. CONCLUSIONS: Drug abuse, and especially cocaine abuse, was associated with lower weight in men. However, infection with HIV and/or hepatitis, malabsorption and resting energy expenditure do not explain these findings.     

Family average income and body mass index above the healthy weight range among urban and rural residents in regional Mainland China

OBJECTIVE: To explore the relationship between family average income (FAI; an index of socio-economic status) and body mass index (BMI; a widely used, inexpensive indicator of weight status) above the healthy weight range in a region of Mainland China. DESIGN: Population-based cross-sectional study, conducted between October 1999 and March 2000 on a sample of regular local residents aged 35 years or older who were selected by random cluster sampling. SETTING: Forty-five administrative villages selected from three urban districts and two rural counties of Nanjing municipality, Mainland China, with a regional population of 5.6 million. SUBJECTS: In total, 29,340 subjects participated; 67.7% from urban and 32.3% from rural areas; 49.8% male and 50.2% female. The response rate among eligible participants was 90.1%. RESULTS: The proportion of participants classified as overweight was 30.5%, while 7.8% were identified as obese. After adjusting for possible confounding variables (age, gender, area of residence, educational level, occupational and leisure-time physical activity, daily vegetable consumption and frequency of red meat intake), urban participants were more likely to be overweight or obese relative to their rural counterparts, more women than men were obese, and participants in the lowest FAI tertile were the least likely to be above the healthy weight range. CONCLUSIONS: The proportion of adults with BMI above the healthy weight range was positively related to having a higher socio-economic status (indexed by FAI) in a regional Chinese population.     

The influence of age and body mass index on relative accuracy of energy intake among Japanese adults

OBJECTIVE: To examine relationships between the ratio of energy intake to basal metabolic rate (EI/BMR) and age and body mass index (BMI) among Japanese adults. DESIGN: Energy intake was assessed by 4-day semi-weighed diet records in each of four seasons (16 days in total). The EI/BMR ratio was calculated from reported energy intake and estimated basal metabolic rate as an indicator of reporting accuracy. SETTING: Residents in three areas in Japan, namely Osaka (urban), Nagano (rural inland) and Tottori (rural coastal). SUBJECTS: One hundred and eighty-three healthy Japanese men and women aged > or =30 years. RESULTS: The oldest age group (> or =60 years) had higher EI/BMR values than the youngest age group (30-39 years) in both sexes (1.74 vs. 1.37 for men; 1.65 vs. 1.43 for women). In multiple regression analyses, age correlated positively (partial correlation coefficient, beta = 0.012, P < 0.001 for men; beta = 0.011, P < 0.001 for women) and BMI correlated negatively (beta = -0.031, P < 0.001 for men; beta = -0.025, P < 0.01 for women) with EI/BMR. CONCLUSION: Age and BMI may influence the relative accuracy of energy intake among Japanese adults.     

Changes in neighbourhood food store environment, food behaviour and body mass index, 1981--1990

OBJECTIVE: This paper examines trends in the neighbourhood food store environment (defined by the number and geographic density of food stores of each type in a neighbourhood), and in food consumption behaviour and overweight risk of 5779 men and women. DESIGN: The study used data gathered by the Stanford Heart Disease Prevention Program in four cross-sectional surveys conducted from 1981 to 1990. SETTING: Four mid-sized cities in agricultural regions of California. SUBJECTS: In total, 3154 women and 2625 men, aged 25-74 years. RESULTS: From 1981 to 1990, there were large increases in the number and density of neighbourhood stores selling sweets, pizza stores, small grocery stores and fast-food restaurants. During this period, the percentage of women and men who adopted healthy food behaviours increased but so did the percentage who adopted less healthy food behaviours. The percentage who were obese increased by 28% in women and 24% in men.ConclusionFindings point to increases in neighbourhood food stores that generally offer mostly unhealthy foods, and also to the importance of examining other food pattern changes that may have a substantial impact on obesity, such as large increases in portion sizes during the 1980s.     

Lipid, protein and carbohydrate intake in relation to body mass index: an Italian study

OBJECTIVE: To analyse the association between macronutrient intake and body mass index (BMI). DESIGN: A series of hospital-based case-control studies. SETTINGS: Selected teaching and general hospitals in several Italian regions. SUBJECTS: A total of 6619 subjects from the comparison groups of the case-control studies were included in the analysis. METHODS: We obtained data from a validated 78-item food-frequency questionnaire submitted between 1991 and 2002. For various macronutrients, the partial regression coefficient (variation of BMI (kg m(-2)) per 100 kcal increment of energy intake) was derived from multiple linear regression models, after allowance for age, study centre, education, smoking habits, number of eating episodes and mutual adjustment for macronutrients. RESULTS: BMI was directly associated with protein intake among women only (beta = 0.68) and with unsaturated fats in both genders (for monounsaturated fats beta = 0.27 for men and 0.26 for women; for polyunsaturated fats beta = 0.27 for men and 0.54 for women), and inversely related to carbohydrates (beta = -0.05 for men and -0.21 for women) and number of eating episodes in both genders (beta = -0.42 for men and -0.61 for women) and to saturated fats among women only (beta = -0.57). CONCLUSIONS: These results confirm and provide convincing evidence that, after allowance for selected covariates including total energy intake, a protein-rich diet is not inversely related to BMI, and a carbohydrate-rich diet is not directly related to BMI.     

Dietary intake and body mass index in HIV-positive and HIV-negative drug abusers of Hispanic ethnicity

OBJECTIVE: Malnutrition in drug abusers has been attributed to poor diet. However, previous studies are conflicting. Many studies have not considered possible concurrent HIV disease. The purpose of this study was to determine the relationship between drug abuse and dietary intake in Hispanic Americans with and without HIV infection. DESIGN: Dietary intake was measured using 3-day food records and 24-hour dietary recalls in three groups: HIV-positive drug abusers, HIV-negative drug abusers and HIV-positive persons who do not use drugs ('non-drug abusers'). SETTING: The baseline data from a prospective cohort study of the role of drug abuse in HIV/AIDS weight loss and malnutrition conducted in Boston, Massachusetts, USA. SUBJECTS: The first 284 participants to enroll in the study. RESULTS: HIV-positive drug abusers had a body mass index (BMI) that was significantly lower than that of HIV-positive non-drug abusers. Reported energy, fat and fibre intakes did not differ between groups. All groups had median reported intakes of vitamin A, vitamin B6, vitamin B12, selenium and zinc that were in excess of the dietary reference values (DRI). Intakes of alpha-tocopherol were below the DRI, but did not differ from intakes of the general US population. However, increasing levels of drug abuse were associated with lower reported intakes of vitamin B6, vitamin B12, selenium and zinc. CONCLUSIONS: Overall, this study does not support the notion that dietary intake can explain the lower BMI of HIV-positive drug abusers. Further studies examining non-dietary determinants of nutritional status in drug abusers are warranted.     

Ethnic differences in body mass index and associated factors of adolescents from minorities in Oslo, Norway: a cross-sectional study

OBJECTIVES: To examine ethnic differences in body mass index (BMI), food habits and physical activity, and determine the factors contributing to differences in BMI. DESIGN AND METHOD: In 2000-2001, 7343 (response rate 88%) 15- and 16-year-old students, enrolled in lower secondary schools in Oslo, participated in the cross-sectional Oslo Health Study. Of these participants, 1719 were defined as ethnic minorities. RESULTS: Significant gender and ethnic differences in mean BMI were observed. Of the ethnic minority adolescents, 5.8% were underweight (<5th percentile of the US Centers for Disease Control and Prevention (CDC)/National Center for Health Statistics (NCHS) reference distribution) and 9.1% were overweight (>85th percentile of the US CDC/NCHS reference distribution). BMI was not significantly associated with either socio-economic factors or physical activity. Food habits and physical activity differed with ethnicity but not with socio-economic factors. An ordinal regression showed that girls from East Asia (odds ratio (OR) 0.4) and boys from sub-Saharan Africa (OR 0.4) had lower BMI than the Western group. Among girls, higher BMI was associated with less frequent consumption of chocolates and sweets, full-fat milk and breakfast (OR 2.4, 1.7 and 1.7, respectively). Higher BMI, for both boys and girls, was associated with current and past dieting (OR 3.7 and 4.2, respectively). CONCLUSIONS: Adolescent food habits and physical activity varied by gender and ethnicity but not with socio-economic factors. BMI was associated with ethnicity, gender and food habits, but no significant relationship was observed with socio-economic factors or physical activity. Ethnicity, in addition to gender, should be taken into consideration when studying BMI and associated factors among adolescents.     

Genetically modified rapeseed oil containing cis-9,trans-11,cis-13-octadecatrienoic acid affects body fat mass and lipid metabolism in mice

Punicic acid, one of the conjugated linolenic acid (CLN) isomers, exerts a body-fat reducing effect. Although punicic acid is found in pomegranate and Tricosanthes kirilowii seeds, the amount of this fatty acid is very low in nature. The goal of this study was to produce a transgenic oil containing punicic acid. A cDNA encoding conjugase that converts linoleic acid to punicic acid was isolated from T. kirilowii, and the plant expression vector, pKN-TkFac, was generated. The pKN-TkFac was introduced into Brassica napus by Agrobacterium-mediated transformation. As a result, a genetically modified rapeseed oil (GMRO) containing punicic acid was obtained, although its proportion to the total fatty acids was very low (approximately 2.5%). The effects of feeding GMRO in ICR CD-1 male mice were then examined. Wild-type rapeseed (B. napus) oil (RSO) containing no CLN was used as a control oil. For reference oils, RSO-based blended oils were prepared by mixing with different levels of pomegranate oil (PO), either 2.5% (RSO + PO) or 5.0% (RSO + 2PO) punicic acid. Mice were fed purified diets containing 10% of either RSO, RSO + PO, RSO + 2PO, or GMRO for 4 weeks, and dietary PO dose-dependently reduced perirenal adipose tissue weight with a significant difference between the RSO group and the RSO + 2PO group. GMRO, as compared to RSO, lowered the adipose tissue weight to the levels observed with RSO + 2PO. The liver triglyceride level of the RSO + 2PO and GMRO groups but not that of the RSO + PO group was lower than that of the RSO group. The RSO + 2PO and GMRO groups, but not the RSO + PO group, had increased carnitine-palmitoyltransferase activity in the liver and brown adipose tissue. These results showed that dietary GMRO, even at a dietary punicic acid level as low as 0.25 wt % of diet, reduced body fat mass and altered liver lipid metabolism in mice and was more effective than an equal amount of punicic acid from PO.     

The association between the body mass index of first-year female university students and their weight-related perceptions and practices, psychological health, physical activity and other physical health indicators

OBJECTIVE: To investigate the association between the weight status of first-year female students (FYFS) and various weight management-related characteristics to identify possible components of a weight management programme for students. DESIGN: Cross-sectional study. SETTING: Female residences at a South African university. SUBJECTS: A total of 360 FYFS. RESULTS: Mean (+/-standard deviation (SD)) body mass index (BMI) of the FYFS was 21.8 +/- 2.6 kg m(-2), with 7.2% being underweight, 81.9% normal-weight, 10.0% overweight and 0.8% obese. Underweight, normal-weight and overweight students differed with regard to their perception of their weight (P < 0.001), weight goals (P < 0.001) and previous weight-loss practices (P < 0.001). Mean+/-SD score on the 26-item Eating Attitudes Test (EAT-26) was 8.5 +/- 9.0 with 8.4% classified as high scorers. Mean+/-SD score on the 34-item Body Shape Questionnaire (BSQ) was 87.7 +/- 32.2, with 76.1% classified as low, 11.9% as medium and 11.9% as high scorers. The self-concept questionnaire indicated that 36.7% had a high, 43.9% a medium and 19.4% a low self-concept. Higher BMI correlated with a higher BSQ score (P < 0.001), a lower self-concept (P = 0.029) and a higher EAT-26 score (P < 0.001). Smoking was prevalent amongst 13.1% of students, and 51.2% used vitamin and/or mineral supplements. Students who quitted smoking had higher (P = 0.006) BMI (22.7 +/- 2.9 kg m(-2)) than those who never smoked before (21.6 +/- 2.5 kg m(-2)). Normal-weight students were more physically active than underweight or overweight students (P = 0.038). CONCLUSIONS: The specific weight management-related needs of FYFS include information about supplement use, smoking, realistic weight goals, safe and sound weight-loss methods, weight cycling, body-shape perceptions, eating attitudes and behaviours, self-concept and physical activity. Interventions aimed at correcting these problems should target all students, regardless of their BMI.     

Physical activity, diet and gene-environment interactions in relation to body mass index and waist circumference: the Swedish young male twins study

OBJECTIVE: The aim of the present study was to examine the relationships between genetic susceptibility to obesity, physical activity (PA), dietary fibre, sugar and fat intakes and 4-year changes in body mass index (BMI) and attained waist circumference (WC) in a cohort of 287 monozygotic and 189 dizygotic young adult male twin pairs. Increased knowledge about interactions between genes and environment may provide insight into why some individuals are more prone to obesity than others. DESIGN: Information about PA, BMI, dietary habits, WC and potential confounders was collected by questionnaire in 1998 and 2002. The cohort data were analysed by mixed linear models. RESULTS: Twins with low PA attained larger WC than twins with high PA (difference 2.5 cm; 95% confidence interval (CI) 1.3, 3.6). The twins with the lowest fibre intake were found to have attained the highest WC and to have increased most in BMI (difference between highest and lowest fibre intakes: 1.6 cm, 95% CI 0.4, 2.9 and 0.45 kg m(-2), 95% CI 0.15, 0.76, respectively). Furthermore, our results suggested the presence of interactions so that twins with genetic susceptibility to obesity were more prone to have larger WC if sedentary than twins without genetic susceptibility. CONCLUSION: PA and a diet rich in fibre may be protective against weight gain among younger adult men. An interaction between PA, genes and attained WC is a novel finding which needs confirmation by other studies.     

Alcohol intake in relation to body mass index and waist-to-hip ratio: the importance of type of alcoholic beverage

OBJECTIVE: Alcohol consumption may play a role in the development of obesity but the relationship between alcohol and weight is still unclear. The aim of our study was to assess the cross-sectional association of intakes of total alcohol and of specific alcoholic beverages (wine, beer and spirits) with waist-to-hip ratio (WHR) and body mass index (BMI) in a large sample of adults from all over France. DESIGN: Cross-sectional. SETTING: Participants were free-living healthy volunteers of the SU.VI.MAX study (an intervention study on the effects of antioxidant supplementation on chronic diseases). SUBJECTS: For 1481 women aged 35-60 years and 1210 men aged 45-60 years, intakes of total alcohol and specific alcoholic beverages were assessed by six 24-hour dietary records. BMI and WHR were measured during a clinical examination the year after. RESULTS: A J-shaped relationship was found between total alcohol consumption and WHR in both sexes and between total alcohol consumption and BMI in men only (P<0.05). The same relationships were observed with wine (P<0.05); men and women consuming less than 100 g day(-1) had a lower BMI (men only) and WHR than non-drinkers or those consuming more. Spirits consumption was positively associated with BMI (linear regression coefficient beta=0.21, 95% confidence interval (CI): 0.09-0.34 and beta=0.22, 95% CI: 0.06-0.39 for men and women, respectively) and WHR (beta=0.003, 95% CI: 0.001-0.005 and beta=0.003, 95%CI: 0.0002-0.006) in both sexes in a linear fashion. No relationship between beer consumption and BMI or WHR was found. CONCLUSION: If confirmed in longitudinal studies, our results indicate that consumption of alcoholic beverages may be a risk factor for obesity.     

The impact of a national mass media campaign in The Netherlands on the prevention of weight gain

OBJECTIVE: A 5-year nationwide mass media campaign aimed at prevention of overweight was organised from 2002 onwards. The present study evaluates the first campaign, which was aimed primarily at increasing awareness of weight gain. DESIGN AND SUBJECTS: Data were collected by telephone interview in four independent cross-sectional surveys among non-obese Dutch adults aged 25-35 years (total n = 1,949) for statistical analyses. Awareness of personal body-weight status, overweight-related risk perceptions, attitudes towards weight-gain prevention, motivation to prevent weight gain and self-reported body mass index (BMI) were measured in each survey. Campaign exposure was assessed in the post-intervention surveys. To identify intervention effects over time multiple linear and logistic regression analyses were used, adjusted for secular time effects and age. RESULTS: After the campaign about 65% of the respondents knew about the campaign. The campaign was associated with more positive attitudes towards the prevention of weight gain (beta = 0.16; P < 0.01) and higher self-reported BMI (beta = 0.14; P < 0.01). CONCLUSIONS: The results suggest that the first campaign reached a large proportion of the population and initiated some positive change in attitudes, but did not achieve significant improvements in other determinants of weight-gain prevention among non-obese young adults.