Television viewing and abdominal obesity in young adults : is the association mediated by food and beverage consumption during viewing time or reduced leisure-time physical activity?

BACKGROUND:The behavioral pathways through which television (TV) viewing leads to increased adiposity in adults are unclear.

OBJECTIVE:We wanted to determine whether the association between TV viewing and abdominal obesity in young adults is mediated by food and beverage consumption during TV viewing time or by a reduction in overall leisure-time physical activity (LTPA).

DESIGN:This study involved a cross-sectional analysis of data from 2001 Australian adults aged 26–36 y. Waist circumference (WC) was measured at study clinics, and TV viewing time, frequency of food and beverage consumption during TV viewing, LTPA, and demographic characteristics were self-reported.

RESULTS:Women watching TV >3 h/d had a higher prevalence of severe abdominal obesity (WC: =88 cm) compared with women watching =1 h/d [prevalence ratio (PR): 1.89; 95% CI: 1.32, 2.71]. Moderate abdominal obesity (WC: 94–101.9 cm) was more prevalent in men watching TV >3 h/d than in men watching =1 h/d (PR: 2.16; 95% CI: 1.37, 3.41). Adjustment for LTPA made little difference, but adjustment for food and beverage consumption during TV viewing attenuated the associations (PR: 1.48; 95% CI: 1.01, 2.17 for women; PR: 1.73; 95% CI: 1.06, 2.83 for men).

CONCLUSIONS:The association between TV viewing and WC in young adults may be partially explained by food and beverage consumption during TV viewing but was not explained by a reduction in overall LTPA. Other behaviors likely contribute to the association between TV viewing and obesity.

Takeaway food consumption, diet quality and abdominal obesity in young adults

Background - Takeaway food consumption is associated with a higher BMI and poorer diet quality in the USA but little is known about the association in Australians.
Objective - To examine if takeaway food consumption is associated with abdominal obesity and poorer diet quality in young Australian adults.
Design - A national sample of 1,277 men and 1,585 women aged 26-36 completed a self-administered questionnaire on demographic and lifestyle factors, a 127 item food frequency questionnaire, and usual frequency of fruit, vegetable and takeaway food consumption. Dietary intake was compared with the dietary recommendations of the Australian Guide to Healthy Eating. A pedometer was worn for seven days. Waist circumference was measured and moderate abdominal obesity was defined as ≥94 cm for men and ≥80 cm for women. Prevalence ratios (PR) were calculated using log binomial regression with eating takeaway food once a week or less as the reference group.
Outcomes - Consumption of takeaway food twice a week or more was reported by more men (37.9%) than women (17.7%). Participants eating takeaway food at least twice a week were less likely to meet the guidelines for vegetables (P<0.05 men and women), fruit (P<0.001 men and women), dairy (P<0.01 men and women), extra foods (P=0.001 men and women), breads and cereals (P<0.05 men only), lean meats and alternatives (P<0.05 women only) and overall met significantly fewer dietary guidelines (P<0.001 men and women) than participants eating takeaway less than twice per week. After adjusting for confounding variables (age, physical activity, TV viewing, and employment status) consuming takeaway food twice a week or more was associated with a 31% higher prevalence of moderate abdominal obesity in men (PR 1.31; 95% CI: 1.07, 1.61) and a 25% higher prevalence in women (PR 1.25; 95% CI: 1.04, 1.50).
Conclusion - Eating takeaway food twice a week or more was associated with poorer diet quality and a higher prevalence of moderate abdominal obesity in both young men and young women.

Health and mortality consequences of abdominal obesity : evidence from the AusDiab study

Objective: To provide an estimate of the morbidity and mortality resulting from abdominal overweight and obesity in the Australian population.

Design and setting: Prospective, national, population-based study (the Australian Diabetes, Obesity and Lifestyle [AusDiab] study).

Participants: 6072 men and women aged ≥ 25 years at study entry between May 1999 and December 2000, and aged ≤ 75 years, not pregnant and for whom there were waist circumference data at the follow-up survey between June 2004 and December 2005.

Main outcome measures: Incident health outcomes (type 2 diabetes, hypertension, dyslipidaemia, the metabolic syndrome and cardiovascular diseases) at 5 years and mortality at 8 years. Comparison of outcome measures between those classified as abdominally overweight or obese and those with a normal waist circumference at baseline, and across quintiles of waist circumference, and (for mortality only) waist-to-hip ratio.

Results: Abdominal obesity was associated with odds ratios of between 2 and 5 for incident type 2 diabetes, dyslipidaemia, hypertension and the metabolic syndrome. The risk of myocardial infarction among obese participants was similarly increased in men (hazard ratio [HR], 2.75; 95% CI, 1.08–7.03), but not women (HR, 1.43; 95% CI, 0.37–5.50). Abdominal obesity-related population attributable fractions for these outcomes ranged from 13% to 47%, and were highest for type 2 diabetes. No significant associations were observed between all-cause mortality and increasing quintiles of abdominal obesity.

Conclusions: Our findings confirm that abdominal obesity confers a considerably heightened risk for type 2 diabetes, the metabolic syndrome (as well as its components) and cardiovascular disease, and they provide important information that enables a more precise estimate of the burden of disease attributable to obesity in Australia.

Takeaway food consumption and its associations with diet quality and abdominal obesity : a cross-sectional study of young adults

Background : Few studies have investigated the associations of takeaway food consumption with overall diet quality and abdominal obesity. Young adults are high consumers of takeaway food so we aimed to examine these associations in a national study of young Australian adults.

Methods : A national sample of 1,277 men and 1,585 women aged 26–36 completed a self-administered questionnaire on demographic and lifestyle factors, a 127 item food frequency questionnaire, usual daily frequency of fruit and vegetable consumption and usual weekly frequency of takeaway food consumption. Dietary intake was compared with the dietary recommendations from the Australian Guide to Healthy Eating. Waist circumference was measured for 1,065 men and 1,129 women. Moderate abdominal obesity was defined as ≥ 94 cm for men and ≥ 80 cm for women. Prevalence ratios (PR) were calculated using log binomial regression. Takeaway food consumption was dichotomised, with once a week or less as the reference group.

Results : Consumption of takeaway food twice a week or more was reported by more men (37.9%) than women (17.7%, P < 0.001). Compared with those eating takeaway once a week or less, men eating takeaway twice a week or more were significantly more likely to be single, younger, current smokers and spend more time watching TV and sitting, whereas women were more likely to be in the workforce and spend more time watching TV and sitting. Participants eating takeaway food at least twice a week were less likely (P < 0.05) to meet the dietary recommendation for vegetables, fruit, dairy, extra foods, breads and cereals (men only), lean meat and alternatives (women only) and overall met significantly fewer dietary recommendations (P < 0.001). After adjusting for confounding variables (age, leisure time physical activity, TV viewing and employment status), consuming takeaway food twice a week or more was associated with a 31% higher prevalence of moderate abdominal obesity in men (PR: 1.31; 95% CI: 1.07, 1.61) and a 25% higher prevalence in women (PR: 1.25; 95% CI: 1.04, 1.50).

Conclusion : Eating takeaway food twice a week or more was associated with poorer diet quality and a higher prevalence of moderate abdominal obesity in young men and women.

Expanding evidence for the multiple dangers of epidemic abdominal obesity

The waistline of America has been expanding now for decades,1 largely as a consequence of an obesogenic environment, with a car-worshipping culture and take-away lifestyle par excellence.2 No upper limit to the prevalence or extent of obesity is yet apparent, and many countries and communities worldwide are busily following the American lead. Accumulating research evidence suggests that the personal and economic costs of the obesity epidemic are immense,3 driven by the obesity-related increases in risk for conditions such as type 2 diabetes mellitus, the metabolic syndrome, cardiovascular disease (CVD), kidney disease, arthritis, cancer, asthma, and sleep-disordered breathing. In addition, decreases are apparent in self-esteem and quality of life.

Involvement of young Australian adults in meal preparation : cross-sectional associations with abdominal obesity and body mass index

Previous research has shown that involvement in meal preparation is positively associated with better diet quality. However, it is unclear whether there is an association between involvement in meal preparation and being overweight or obese. This study investigated whether the level of involvement in meal preparation was associated with objectively measured weight status in young adults. During 2004-2006, a national sample of 1,996 Australian adults aged 26 to 36 years completed a self-administered questionnaire including questions on sociodemographic characteristics, diet, and physical activity. Participants were asked to report who usually prepared the main meal on working days and responses were categorized as “myself,” “shared,” or “someone else.” Waist circumference, weight, and height were measured by trained staff. Moderate abdominal obesity was defined as waist circumference >94 cm for men and >80 cm for women. Overweight was defined as body mass index (calculated as kg/m2) >25. Prevalence ratios were calculated using log binomial regression. After adjusting for age, education, and leisure time physical activity, men who shared the meal preparation had a slightly lower prevalence of moderate abdominal obesity (prevalence ratio=0.92; 95% confidence interval [CI]: 0.86 to 0.99) than those whose meals were usually prepared by someone else. There was no association with having sole responsibility (prevalence ratio=0.99; 95% CI: 0.92 to 1.06). There were no associations between level of involvement in meal preparation and being overweight (shared responsibility prevalence ratio=0.99; 95% CI: 0.92 to 1.07; sole responsibility prevalence ratio=0.98; 95% CI: 0.91 to 1.05). For women, level of involvement was not associated with moderate abdominal obesity (shared responsibility prevalence ratio=0.93; 95% CI: 0.84 to 1.03; sole responsibility prevalence ratio=0.94; 95% CI: 0.86 to 1.03) or being overweight (shared responsibility prevalence ratio=0.93; 95% CI: 0.84 to 1.02; sole responsibility prevalence ratio=0.93; 95% CI: 0.85 to 1.02). In this sample of young adults, level of involvement in meal preparation was not strongly related to weight status.

The influence of hip circumference on the relationship between abdominal obesity and mortality

Background Higher waist circumference and lower hip circumference are both associated with increased cardiovascular disease (CVD) risk, despite being directly correlated. The real effects of visceral obesity may therefore be underestimated when hip circumference is not fully taken into account. We hypothesized that adding waist and hip circumference to traditional risk factors would significantly improve CVD risk prediction.

Methods In a population-based survey among South Asian and African Mauritians (n = 7978), 1241 deaths occurred during 15 years of follow-up. In a model that included variables used in previous CVD risk calculations (a Framingham-type model), the association between waist circumference and mortality was examined before and after adjustment for hip circumference. The percentage with an increase in estimated 10-year cumulative mortality of >25% and a decrease of >20% after waist and hip circumference were added to the model was calculated.

Results Waist circumference was strongly related to mortality only after adjustment for hip circumference and vice versa. Adding waist and hip circumference to a Framingham-type model increased estimated 10-year cumulative CVD mortality by >25% for 23.7% of those who died and 15.7% of those censored. Cumulative mortality decreased by >20% for 4.5% of those who died and 14.8% of those censored.

Conclusions The effect of central obesity on mortality risk is seriously underestimated without adjustment for hip circumference. Adding waist and hip circumference to a Framingham-type model for CVD mortality substantially increased predictive power. Both may be important inclusions in CVD risk prediction models.

Changes in abdominal obesity and age-related macular degeneration: the atherosclerosis risk in communities study

OBJECTIVE: To examine the association between changes in waist-hip ratio (WHR), a measure of abdominal obesity, and age-related macular degeneration (AMD). METHODS: A total of 12 515 persons from a population-based cohort study, aged 45 to 64 years in 1987 to 1989, were followed up over 6 years. The percentage change in WHR during follow-up was ranked into sex-specific deciles; an increase in WHR was defined as the top 10% of change and a decrease in WHR as the bottom 10%. The association of increased or decreased WHR and presence of AMD at follow-up was determined using logistic regression adjusting for potential confounders. RESULTS: The average change in WHR was an increase of 2%, ranging from a decrease of 44% to an increase of 102%. A decrease in WHR of 3% or more was associated with 29% lower odds of any AMD (odds ratio = 0.71; 95% confidence interval, 0.52-0.97). This effect was most pronounced among obese participants at baseline, where a decrease in WHR was associated with 59% lower odds of AMD (odds ratio = 0.41; 95% confidence interval, 0.20-0.82). CONCLUSIONS: Middle-aged persons who had a 3% or greater reduction in WHR over time were less likely to have AMD, particularly among those who were initially obese.

Overweight, obesity and metabolic syndrome in rural southeastern Australia

OBJECTIVE: To measure the prevalence of overweight, obesity and the metabolic syndrome (MetS) in rural Australia.

DESIGN, SETTING AND PARTICIPANTS: Cross-sectional surveys were conducted in two rural areas in Victoria and South Australia in 2004-2005. A stratified random sample of men and women aged 25-74 years was selected from the electoral roll. Data were collected by a self-administered questionnaire, physical measurements and laboratory tests.

MAIN OUTCOME MEASURES: Prevalence of overweight and obesity, as defined by body mass index (BMI) and waist circumference; prevalence of MetS and its components.

RESULTS: Data on 806 participants (383 men and 423 women) were analysed. Based on BMI, the prevalence of overweight and obesity combined was 74.1% (95% CI, 69.7%-78.5%) in men and 64.1% (95% CI, 59.5%-68.7%) in women. Based on waist circumference, the prevalence of overweight and obesity was higher in women (72.4%; 95% CI, 68.1%-76.7%) than men (61.9%; 95% CI, 57.0%-66.8%). The overall prevalence of obesity was 30.0% (95% CI, 26.8%-33.2%) based on BMI (> or = 30.0 kg/m(2)) and 44.7% (95% CI, 41.2%-48.1%) based on waist circumference (> or = 102 cm [men] and > or= 88 cm [women]). The prevalence of MetS as defined by the US National Cholesterol Education Program Adult Treatment Panel III 2005 criteria was 27.1% (95% CI, 22.7%-31.6%) in men and 28.3% (95% CI, 24.0%-32.6%) in women; based on International Diabetes Federation criteria, prevalences for men and women were 33.7% (95% CI, 29.0%-38.5%) and 30.1% (95% CI, 25.7%-34.5%), respectively. Prevalences of MetS, central (abdominal) obesity, hyperglycaemia, hypertension and hypertriglyceridaemia increased with age.

CONCLUSIONS: In rural Australia, prevalences of MetS, overweight and obesity are very high. Urgent population-wide action is required to tackle the problem.

Overweight, obesity and metabolic syndrome in rural south-eastern Australia

Aims & rationale/Objectives : To measure the prevalence of overweight, obesity and the metabolic syndrome in rural Australia.</p>

Methods :Two cross-sectional population surveys of chronic disease risk factors were carried out in rural Victoria (Corangamite Shire) and South Australia (Limestone Coast) in 2004-05. For both surveys, a stratified random sample of the population aged 25 to 74 years was drawn from the electoral roll. The surveys comprised a self-administered questionnaire, physical measurements and laboratory tests.</p>

Principal findings : A total of 841 individuals had complete questionnaire, health check and measured MetS data. The prevalence of overweight and obesity was 75% in males and 64.7% in females defined by BMI. Using waist circumference, the prevalence of overweight and obesity was higher in females (72.9%) than in males (63.2%). The overall prevalence of obesity of was 30.1% when defined by BMI, but 44.8% when defined by waist circumference. The prevalence of metabolic syndrome according to NCEP ATP III 2005 criteria was 29.0% in males and 28.5% in females. According to IDF criteria, the prevalence for males and females were 30.5% and 36.3%, respectively. The prevalence of metabolic syndrome and central (abdominal) obesity, hyperglycaemia, hypertension, and hypertriglyceridaemia increased with age.

Discussion : The prevalence of overweight and obesity, in particular central obesity, in rural Australia is very high as is the prevalence of metabolic syndrome.

Implications : Urgent population wide action is required to turn this trend around and regular monitoring of the trends in response to such action is essential.

Reducing psychological distress and obesity in Australian farmers by promoting physical activity

Background: Studies have confirmed that the rate of mental illness is no higher in rural Australians than that of urban Australians. However, the rate of poor mental health outcomes, and in particular suicide, is significantly raised in rural populations. This is thought to be due to lack of early diagnosis, health service access, the distance-decay effect, poor physical health determinants and access to firearms. Research conducted by the National Centre for Farmer Health between 2004 and 2009 reveals that there is a correlation between obesity and psychological distress among the farming community where suicide rates are recognised as high. Chronic stress overstimulates the regulation of the hypothalamic-pituitary-adrenal (HPA) axis that is associated with abdominal obesity. Increasing physical activity may block negative thoughts, increase social contact, positively influence brain chemistry and improve both physical and mental health. This paper describes the design of the Farming Fit study that aims to identify the effect of physical activity on psychological distress, obesity and health behaviours such as diet patterns and smoking in farm men and women.
Methods/Design: For this quasi-experimental (convenience sample) control-intervention study, overweight (Body Mass Index ≥25 kg/m2) farm men and women will be recruited from Sustainable Farm Families™ (SFF) programs held across Victoria, Australia. Baseline demographic data, health data, depression anxiety stress scale (DASS) scores, dietary information, physical activity data, anthropometric data, blood pressure and biochemical analysis of plasma and salivary cortisol levels will be collected. The intervention group will receive an exercise program and regular phone coaching in order to increase their physical activity. Analysis will evaluate the impact of the intervention by longitudinal data (baseline and post intervention) comparison of intervention and control groups.
Discussion: This study is designed to examine the effect of physical activity on psychological health and other comorbidities such as obesity, impaired glucose tolerance, hypertension and dyslipidaemia within a high-risk cohort. The outcomes of this research will be relevant to further research and service delivery programs, in particular those tailored to rural communities.

Paraoxonase (PON)1 Q192R functional genotypes and PON1 Q192R genotype by smoking interactions are risk factors for the metabolic syndrome, but not overweight or obesity

Background The metabolic syndrome (MetS) is a complex of multiple risk factors that contribute to the onset of cardiovascular disorder, including lowered levels of high-density lipoprotein (HDL) and abdominal obesity. Smoking, mood disorders, and oxidative stress are associated with the MetS. Paraoxonase (PON)1 is an antioxidant bound to HDL, that is under genetic control by functional polymorphisms in the PON1 Q192R coding sequence. Aims and methods This study aimed to delineate the associations of the MetS with plasma PON1 activity, PON1 Q192R genotypes, smoking, and mood disorders (major depression and bipolar disorder), while adjusting for HDL cholesterol, body mass index, age, gender, and sociodemographic data. We measured plasma PON1 activity and serum HDL cholesterol and determined PON1 Q192R genotypes through functional analysis in 335 subjects, consisting of 97 with and 238 without MetS. The severity of nicotine dependence was measured using the Fagerström Nicotine Dependence Scale. Results PON1 Q192R functional genotypes and PON1 Q192R genotypes by smoking interactions were associated with the MetS. The QQ and QR genotypes were protective against MetS while smoking increased metabolic risk in QQ carriers only. There were no significant associations between PON1 Q192R genotypes and smoking by genotype interactions and obesity or overweight, while body mass index significantly increased MetS risk. Smoking and especially severe nicotine dependence are significantly associated with the MetS although these effects were no longer significant after considering the effects of the smoking by PON1 Q192R genotype interaction. The MetS was not associated with mood disorders, major depression or bipolar disorder. Discussion PON1 Q192R genotypes and genotypes by smoking interactions are risk factors for the MetS that together with lowered HDL and increased body mass and age contribute to the MetS.

24-h urinary sodium excretion is associated with obesity in a cross-sectional sample of Australian schoolchildren

Emerging evidence indicates that dietary Na may be linked to obesity; however it is unclear whether this relationship is independent of energy intake (EI). The aim of this study was to assess the association between Na intake and measures of adiposity, including BMI z score, weight category and waist:height ratio (WHtR), in a sample of Australian schoolchildren. This was a cross-sectional study of schoolchildren aged 4-12 years. Na intake was assessed via one 24-h urine collection. BMI was converted to age- and sex-specific z scores, and WHtR was used to define abdominal obesity. In children aged ≥8 years, EI was determined via one 24-h dietary recall. Of the 666 children with valid urine samples 55 % were male (average age 9·3 (sd 1·8) years). In adjusted models an additional 17 mmol/d of Na was associated with a 0·10 higher BMI z score (95 % CI 0·07, 0·13), a 23 % (OR 1·23; 95 % CI 1·16, 1·31) greater risk of being overweight/obese and a 15 % (OR 1·15; 95 % CI 1·09, 1·23) greater risk of being centrally obese. In the subsample of 8-12-year-old children (n 458), adjustment for EI did not markedly alter the associations between Na and adiposity outcomes. Using a robust measure of daily Na intake we found a positive association between Na intake and obesity risk in Australian schoolchildren, which could not be explained by total energy consumption. To determine whether this is a causal relationship, longitudinal studies, with high-quality measures of Na and EI, are required.