Mediterranean diet in relation to body mass index and waist-to-hip ratio

OBJECTIVE: The Mediterranean diet is rich in fat and starch, and hence may be related to overweight. We therefore investigated the relationship between adherence to a Mediterranean diet and body mass index (BMI) and waist-to-hip ratio (WHR). DESIGN AND SETTING: Data were obtained from the control group of a network of case-control studies on cancer conducted in major teaching and general hospitals in four Italian areas between 1991 and 2002. An interviewer-administered validated 78-item food-frequency questionnaire was used to obtain information on the subjects' habitual diet. Information on socio-economic factors, lifestyle habits and anthropometric measures was also collected. A Mediterranean diet score (MDS) was derived on the basis of eight characteristics of the Mediterranean diet. SUBJECTS: Subjects were 6619 patients (3090 men, 3529 women) admitted to hospital for a wide spectrum of acute, non-neoplastic conditions, unrelated to known risk factors for cancer and long-term modifications of diet. RESULTS: In multiple linear regression models adjusted for age, study centre, education, tobacco smoking, occupational physical activity and total energy intake, the MDS was not related to BMI (beta = 0.05 for men and -0.04 for women) or WHR (beta = 0.000 and 0.001, respectively) in both sexes. CONCLUSIONS: Adherence to the major characteristics of the Mediterranean diet is unrelated to BMI and WHR, confirming previous data from Greece and Spain.     

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.     

Body mass index, waist circumference and waist-to-hip ratio cut-off points for categorisation of obesity among Omani Arabs

BACKGROUND: There are no data on optimal cut-off points to classify obesity among Omani Arabs. The existing cut-off points were obtained from studies of European populations. OBJECTIVE: To determine gender-specific optimal cut-off points for body mass index (BMI), waist circumference (WC) and waist-to-hip ratio (WHR) associated with elevated prevalent cardiovascular disease (CVD) risk among Omani Arabs. DESIGN: A community-based cross-sectional study. SETTING: The survey was conducted in the city of Nizwa in Oman in 2001. SUBJECTS AND METHODS: The study contained a probabilistic random sample of 1421 adults aged > or =20 years. Prevalent CVD risk was defined as the presence of at least two of the following three risk factors: hyperglycaemia, hypertension and dyslipidaemia. Logistic regression and receiver-operating characteristic (ROC) curve analyses were used to determine optimal cut-off points for BMI, WC and WHR in relation to the area under the curve (AUC), sensitivity and specificity. RESULTS: Over 87% of Omanis had at least one CVD risk factor (38% had hyperglycaemia, 19% hypertension and 34.5% had high total cholesterol). All three indices including BMI (AUC = 0.766), WC (AUC = 0.772) and WHR (AUC = 0.767) predicted prevalent CVD risk factors equally well. The optimal cut-off points for men and women respectively were 23.2 and 26.8 kg m-2 for BMI, 80.0 and 84.5 cm for WC, and 0.91 and 0.91 for WHR. CONCLUSIONS: To identify Omani subjects of Arab ethnicity at high risk of CVD, cut-off points lower than currently recommended for BMI, WC and WHR are needed for men while higher cut-off points are suggested for women.     

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.     

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.     

Mortality attributable to higher-than-optimal body mass index in New Zealand

OBJECTIVES: To estimate the burden of mortality in New Zealand due to higher-than-optimal body mass index (BMI) in 1997, as well as mortality that could be avoided in 2011 with feasible changes in mean population BMI. SETTING: New Zealand. DESIGN: Comparative risk assessment methodology was used to estimate the attributable and avoidable mortality due to high BMI. Outcomes assessed were ischaemic heart disease (IHD), ischaemic stroke, type 2 diabetes mellitus, colorectal cancer and postmenopausal breast cancer. RESULTS: In 1997, 3154 deaths (11% of all deaths) in New Zealand were due to higher-than-optimal BMI (>21 kg m(-2)). This amounted to 83% of diabetes deaths, 24% of IHD deaths, 15% of ischaemic stroke deaths and 4% of all cancer deaths. If the projected increase in mean population BMI by 2011 was limited to 1.0 kg m(-2) rather than 1.3 kg m(-2), approximately 385 deaths could be prevented annually, mainly from diabetes. CONCLUSIONS: These results quantify the importance of higher-than-optimal BMI as a major modifiable cause of premature death in New Zealand. Intervention policies that would have only modest effects on slowing the rate of increase in mean population BMI by 2011 could still prevent hundreds of deaths annually.     

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.     

Monetary costs of dietary energy reported by young Japanese women: association with food and nutrient intake and body mass index

OBJECTIVE: Little is known about the relationship of monetary diet costs to dietary intake and obesity, particularly in non-Western populations. This study examined monetary cost of dietary energy in relation to diet quality and body mass index (BMI) among young Japanese women. DESIGN: Dietary intake was assessed by a validated, self-administered, diet history questionnaire. Diet costs were estimated using retail food prices. Monetary cost of dietary energy (Japanese yen 1000 kcal-1) was then calculated. BMI was computed from self-reported body weight and height. SUBJECTS: A total of 3931 female Japanese dietetic students aged 18-20 years. RESULTS: Monetary cost of dietary energy was positively associated with intakes of fruits, vegetables, fish and shellfish, and pulses; however, higher monetary cost of dietary energy was also associated with higher consumption of fat and oil, meat and energy-containing beverages, and lower consumption of cereals (rice, bread and noodles) (all P for trend <0.01). At the nutrient level, monetary cost of dietary energy was positively associated with intakes of dietary fibre and key vitamins and minerals, but also associated positively with intakes of fat, saturated fatty acids, cholesterol and sodium, and negatively with carbohydrate intake (all P for trend <0.0001). After adjustment for possible confounders, monetary cost of dietary energy was quite weakly but significantly negatively associated with BMI (P for trend = 0.0197). CONCLUSIONS: Increasing monetary cost of dietary energy was associated with both favourable and unfavourable dietary intake patterns and a quite small decrease in BMI in young Japanese women.     

Associations between salivary bacteria and reported sugar intake and their relationship with body mass index in women and their adolescent children

OBJECTIVE: To study associations between reported sugar intake and salivary bacteria (mutans streptococci, MS and lactobacilli, LB), and sugar intake in relation to body mass index (BMI), in women and adolescents. DESIGN: Cross-sectional study. Habitual dietary intake was reported in a questionnaire and whole saliva samples were collected and cultivated. SETTING: Stockholm, Sweden. SUBJECTS: Four hundred and fourteen mothers and their 16-year-old children (57% girls). RESULTS: Reported total sugar intake was significantly associated with LB in mothers (P = 0.001), but not in daughters and sons (P = 0.03 for mother-son interaction). When excluding lactose, the associations with LB and MS were significant in daughters (P = 0.032 and 0.005, respectively). High BMI and sugar intake from milk were independently associated with MS counts in mothers in a multiple regression model (R2 = 0.053). In daughters, sugar from beverages, candies/chocolates and fruits were all independently associated with MS counts (R2 = 0.074), whereas in sons, only mothers' MS counts were associated (R2 = 0.084). High BMI, low intake from cooked meals and high intake of candies/chocolates were all independently associated with LB in mothers (R2 = 0.076), while, except for candies/chocolates in daughters, no significant associations were found in children. BMI was significantly associated with bacteria counts in both mothers and children, whereas reported sugar intake was not. CONCLUSION: The associations between reported sugar intake and bacteria were generally weak. In mothers and daughters, some significant associations were found, but not in sons. Bacteria counts, but not reported sugar intake, were positively associated with BMI.     

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.     

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.     

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.     

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.     

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.