D. Dunbar

Influence of gender and socio-economic status on dietary patterns and nutrient intakes in 18-year-old Australians

This study used two‐day diet records to examine dietary behaviours in 504 Australian 18 year‐olds in relation to gender, socio‐economic status (SES) and national dietary guidelines. Fat intake exceeded 30% of energy in about 80% of subjects and was greater than 40% in about one‐quarter. Saturated fat provided more than 10% of dietary energy in more than 90% of participants; less than 1% achieved a polyunsaturated to saturated fat ratio of at least one. The major food groups contributing to fat intake were convenience foods (32% in men, 28% in women) and meat (27% in men, 25% in women). Fibre intake was less than 30 g/day in 93% of women and 77% of men. Intakes of calcium, magnesium, potassium, and vitamins C and A, as a ratio of energy consumption, were greater in women than men, while sodium intake was significantly higher in men. Convenience foods were the greatest contributors to sodium intake (27% in men, 22% in women) followed by meat, bread, and soups and sauces. Greater consumption of cereals, fruit, vegetables and low‐fat foods in young women of higher SES was reflected in their nutrient profile with higher intake of fibre and vitamin C and lower intake of fat. Men ate more cereals, meat and sugary foods and less fruit, vegetables and low‐fat foods. Only 2.5% of men and 4.1% of women conformed with the health promotion message, widely publicised locally, to eat two fruits and five vegetables daily. Not eating breakfast was associated with lower calcium intake in men and women, and lower iron and fibre intake in women. Achieving behavioural changes in young adults must take into account differences in dietary behaviour related to gender and SES.

Tracking of blood pressure in Australian children.

Objective Tracking of blood pressure (BP) from childhood occurs in populations but, for individuals, prediction of adult BP from childhood levels is poor. We examined factors that may influence tracking of BP to identify better predictors of higher BP in early adult life. Design A prospective study of children recruited at the age of 9 years by random sampling of Perth metropolitan schools stratified by socio-economic status. Setting Community based with re-surveys 3-yearly for 9 years. Participants A total of 516 boys and 520 girls at 9 years; 680 boys and 630 girls at 12 years; 318 boys and 300 girls at 15 years; 330 men and 326 women at 18 years. Main outcome measures Systolic (SBP) and diastolic (DBP) BP. Results Persistence in the highest quartile for SBP between surveys was seen in 34–48% of subjects and in 37% between the ages of 9 and 18 years. The proportion increased to around 60% in those in the highest quartile for body mass index (BMI), to 70% in those in the highest quartile for change in BMI and to 60% if there was a family history of hypertension. In log-linear models, persistence in a quartile for SBP was significantly related to a family history of hypertension, previous SBP, BMI and change in BMI. Relationships were similar for DBP. Conclusions Excessive weight gain in adolescence and a family history of hypertension substantially increase the risk of higher BP persisting into early adult life. Recognition of children at risk would allow early intervention emphasizing weight control with potential long-term benefits.

Environmental temperature and blood pressure in 9-year-old Australian children.

Relationships between blood pressure (BP) and environmental temperature were investigated as part of a broader study of constitutional and environmental determinants of BP in a sample of 1037 9-year-old Australian children. A Dinamap semi-automatic device was used to obtain three BP readings for each child. Average systolic blood pressure (SBP) and diastolic blood pressure (DBP) differed according to month of examination, with higher levels in the colder months. Negative relationships were observed between BP and temperature on the measurement day; computed regression equations indicated that a rise in maximum daily temperature of 10 degrees C was associated with falls of 5-7 mmHg in SBP and DBP. The relationships were independent of age, weight, height, socio-economic status and heart rate (HR). The results emphasize the importance of taking environmental temperatures into account in epidemiological studies of BP.

Dietary fish oils increase serum lipids in insulin-dependent diabetics compared with healthy controls

The effect of daily dietary supplementation with fish oil on serum lipids and platelet total phospholipid fatty acids was examined in male normolipidemic insulin-dependent diabetics and normal controls. They were given 15 g/d of fish oil as Max EPA (equivalent to 2.7 g/d of eicosapentaenoic acid) for 3 weeks. The diabetics showed a rise in total cholesterol, attributable to increases in LDL- and HDL-cholesterol. The increase in HDL-cholesterol was largely due to a rise in its HDL2 subclass. There was also a decrease in triglycerides in both groups. Similar changes in lipids were seen in the normal controls, although these were not significant. The more pronounced effect in diabetics suggests an altered metabolic response to omega-3 fatty acids in that disorder. However, the results indicate that the possible detrimental effect of the rise in total and LDL-cholesterol following fish oil may be offset by the increase in the protective HDL2 subclass.

Comparison of diets supplemented with fish oil or olive oil on plasma lipoproteins in insulin-dependent diabetics

This study was designed to compare changes in high-density lipoprotein (HDL)- and low-density lipoprotein (LDL)-cholesterol in normolipidaemic male insulin-dependent diabetics (IDD) following dietary supplementation with either the fish oil concentrate Max EPA or olive oil. The contribution of the small quantity of cholesterol in Max EPA to these changes was also examined. Twenty-seven subjects were matched in groups of three and randomly allocated to one of three treatment groups of nine subjects each. Subjects were given 15 1-g capsules of oil daily for 3 weeks, consisting of either Max EPA, olive oil, or olive oil to which was added the same amount of cholesterol as contained in Max EPA, respectively. There was a significant increase in eicosapentaenoic acid, and a decrease in arachidonic acid, in the platelet membrane phospholipids of subjects taking Max EPA. In this group, there was an approximately 30% increase in serum HDL2-cholesterol (0.59 +/- 0.07 to 0.77 +/- 0.11 mmol/L, mean +/- SEM; P less than .01) and a corresponding decrease in HDL3-cholesterol (0.79 +/- 0.03 to 0.71 +/- 0.03 mmol/L; P less than .05). Although total and LDL-cholesterol concentrations were also higher after Max EPA, the changes were not significant. Triglycerides were significantly decreased by Max EPA. There were no significant changes in lipids in the groups given olive oil. These results show that compared with olive oil, dietary supplementation with Max EPA substantially increases HDL2-cholesterol in insulin-dependent diabetics. This is most likely due to a selective effect of omega 3 fatty acids.(ABSTRACT TRUNCATED AT 250 WORDS)

Stages of change for health-related behaviours in 18 year-old Australians

Abstract This study investigated the validity of a Stages of Change algorithm with respect to independent measures of physical activity and fitness. dietary intake and alcohol consumption in 18 year-old Ausmlian men (n = 301) and women (n = 282). Stage of Change categories were related to fat and fibre intakes in men and fibre intake in women as well as hit and vegetable intakes in men and women. Physical activity and fitness for men and women also showed significant linear associations with Stage of Change categories. Alcohol consumption was significantly associated with Stage of Change categories for men but not for women although recorded alcohol consumption was very variable for women. However, the algorithm was valid for both men and women when drinking alcohol consistent with national guidelines on safe drinking was used. In summary, with reference to actual health behaviours, the Stages of Change algorithm was valid for young men and women for diet. physical activity and alcohol drinking. Independent behavioural data were not available for smoking behaviours. Using the algorithm, there were significant associations in men between prccontemplation status for diet and drinking and diet and physical activity, in women between diet and smoking and in both men and women between drinking and smoking. Covariance between precontemplation status for different health behaviours therefore suggests the need for multimodal interventions.

SERUM LIPIDS IN INSULIN‐DEPENDENT DIABETICS ARE MARKEDLY ALTERED BY DIETARY FISH OILS

1. The effect of dietary fish oil supplementation on serum lipids was examined in normolipidaemic insulin‐dependent male diabetics and healthy controls. Fish oil was given as Max eicosapentaenoic acid (EPA), 15 g daily (equivalent to 2.7 g/day of EPA) for 3 weeks.