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To elicit predictors of variation in likelihood to purchase foods rich in
long-chain omega-3 fatty acids.
Design, setting and subjects
Responses from a community sample (n =
220) were elicited using a computer-administered questionnaire based on an
adaptation of Protection Motivation Theory including measures of perceived
risk and vulnerability to coronary heart disease (CHD). Other measures
included health status, body mass index (BMI), perceived risk/benefits of
novel technologies and sociodemographics. Descriptions of model products
were presented, including farmed fish fed fishmeal (FFFF); farmed fish fed
genetically modified (GM) oilseed (FFFGM); bread, milk and supplements
containing fish oil (SFO) or GM oilseed. It was hypothesised that perceived
vulnerability to CHD would enhance acceptance of GM products (H1).
Furthermore, information describing the benefits of LCO3FA, limitations to
fish supply and potential alternatives was given to a treatment group (50%)
and hypothesised to have a positive effect on the acceptance of GM products
(H2).
Results
No evidence was found to support H1 or H2. FFFF was most likely to be
purchased (P < 0.01), followed
by SFO and FFFGM. Multivariate regression analysis identified significant
(P < 0.05) predictors
(standardised β) for
likelihood to purchase FFFF: self-efficacy 0.56; behaviour (product)
efficacy 0.19; belief that fishmeal is unnatural −0.14 (R2 = 0.44) and for FFFGM:
self-efficacy 0.65; perceived severity of CHD 0.15; BMI −0.13;
significant other has/had arthritis 0.11; belief that GM oilseed is
unnatural 0.11 (R2 =
0.49).
Conclusions
Self-efficacy (confidence to consume) was the most important predictor of
likelihood to purchase all products.
Recent research indicates that n–3 fatty acids can inhibit cognitive decline,
perhaps differentially by hypertensive status.
Design
We tested these hypotheses in a prospective cohort study (the Atherosclerosis
Risk in Communities). Dietary assessment using a food-frequency
questionnaire and plasma fatty acid exposure by gas chromatography were
completed in 1987–1989 (visit 1), while cognitive assessment with
three screening tools – the Delayed Word Recall Test, the Digit
Symbol Substitution Test of the Wechsler Adult Intelligence
Scale–Revised and the Word Fluency Test (WFT) – was
completed in 1990–1992 (visit 2) and 1996–1998 (visit
4). Regression calibration and simulation extrapolation were used to control
for measurement error in dietary exposures.
Setting
Four US communities – Forsyth County (North Carolina), Jackson
(Mississippi), suburbs of Minneapolis (Minnesota) and Washington County
(Maryland).
Subjects
Men and women aged 50–65 years at visit 1 with complete dietary
data (n = 7814); white men and women in
same age group in the Minnesota field centre with complete plasma fatty acid
data (n = 2251).
Results
Findings indicated that an increase of one standard deviation in dietary
long-chain n–3 fatty acids (%
of energy intake) and balancing long-chain n−3/n–6 decreased the risk of 6-year cognitive decline in
verbal fluency with an odds ratio (95% confidence interval) of 0.79
(0.66–0.95) and 0.81 (0.68–0.96), respectively, among
hypertensives. An interaction with hypertensive status was found for dietary
long-chain n–3 fatty acids (g
day−1) and WFT decline (likelihood ratio test,
P = 0.06). This exposure in plasma
cholesteryl esters was also protective against WFT decline, particularly
among hypertensives (OR = 0.51, P
< 0.05).
Conclusion
One implication from our study is that diets rich in fatty acids of marine
origin should be considered for middle-aged hypertensive subjects. To this
end, randomised clinical trials are needed.
To test the hypothesis that maternal food fortification with omega-3 fatty
acids and multiple micronutrients increases birth weight and gestation
duration, as primary outcomes.
Design
Non-blinded, randomised controlled study.
Setting
Pregnant women received powdered milk during their health check-ups at 19
antenatal clinics and delivered at two maternity hospitals in Santiago,
Chile.
Subject
Pregnant women were assigned to receive regular powdered milk (n = 477) or a milk product fortified with
multiple micronutrients and omega-3 fatty acids (n = 495).
Results
Intention-to-treat analysis showed that mean birth weight was higher in the
intervention group than in controls (65.4 g difference, 95% confidence
interval (CI) 5–126 g; P =
0.03) and the incidence of very preterm birth (<34 weeks) was
lower (0.4% vs. 2.1%; P = 0.03).
On-treatment analysis showed a mean birth weight difference of 118 g (95% CI
47–190 g; P = 0.001) and a
relative fall in both the proportion of birth weight ≤3000 g
(P = 0.015) and the incidence of
pre-eclampsia (P = 0.015). Compliance
with the experimental product was apparent from a haematological study of
red-blood-cell folate at the end of pregnancy, which was performed in a
sub-sample. In both types of analyses, positive differences were also
present for mean gestation duration, birth length and head circumference.
Nevertheless, the relatively small sample sizes allowed a statistical power
of >0.80 just for mean birth weight and birth length in the
on-treatment analysis; birth length in that analysis had a difference of
0.57 cm (95% CI 0.19–0.96 cm; P = 0.003).
Conclusions
The new intervention resulted in increased mean birth weight. Associations
with gestation duration and most secondary outcomes need a larger sample
size for confirmation.
To describe (1) the prevalence of overweight and obesity and their
association with physical activity; (2) the effect of different cut-off
points for body mass index (BMI) on weight status categorisation; and (3)
associations of weight status with perceptions of body size, health and diet
quality.
Design
A cross-sectional study.
Setting
Secondary schools in Barbados.
Subjects
A cohort of 400 schoolchildren, 11–16 years old, selected to study
physical education practices.
Results
Prevalence of overweight (15% boys; 17% girls) and obesity (7% boys; 12%
girls) was high. Maternal obesity, as defined by the International Obesity
Task Force (IOTF) BMI cut-off points, predicted weight status such that
reporting an obese mother increased the odds of being overweight by 5.25
(95% confidence interval: 2.44, 11.31). Physical activity was inversely
associated with weight status; however levels were low. Recreational
physical activity was not associated with weight status in either category.
Overweight subjects tended to misclassify themselves as normal weight and
those who misclassified perceived themselves to be of similar health status
to normal-weight subjects. The National Center for Health Statistics and
IOTF BMI cut-off points produced different estimates of overweight and
obesity.
Conclusions
Our findings suggest that inadequate physical activity and ignorance related
to food and appropriate body size are promoting high levels of adiposity
with a strong contribution from maternal obesity, which may be explained by
perinatal and other intergenerational effects acting on both sexes.
Prevalence studies and local proxy tools for adiposity assessment are
needed.
To identify determinants of adolescents’ consumption of carbonated
soft drinks (regular and diet), both of total consumption and of consumption
at school.
Design/Setting/Subjects
Regular and diet soft drink consumption was measured by food frequency
questions that were dichotomised. Several potential environmental and
personal determinants of consumption were measured. A total of 2870
(participation rate: 85%) 9th and 10th graders, within 33 Norwegian schools,
participated in the study. Multilevel logistic regression analyses were
preformed for total soft drink consumption (twice a week or more vs. less)
and for consumption at school (once a week or more vs. less).
Results
A total of 63% and 27% of the participants reported to drink respectively
regular and diet soft drinks twice a week or more, and 24% and 8%,
respectively, reported to drink soft drinks once a week or more at school.
Preferences, accessibility, modelling and attitudes were the strongest
determinants of both regular and diet soft drink consumption. In addition,
gender, educational plans and dieting were related to both total soft drink
consumption and consumption at school. Pupils with longer distance from
school to shop and those in schools with rules concerning soft drink
consumption tended to have lower odds of drinking both regular and diet soft
drinks at school.
Conclusion
This study shows that gender, educational plans, dieting, accessibility,
modelling, attitudes and preferences all seem to be strong determinants of
adolescents’ soft drink consumption. Parents and the home
environment appear as great potential intervention targets.
To create, validate and assess the reliability of a checklist to measure
calcium intake in children.
Design
Calcium intakes from a checklist and parent-assisted 24-h dietary recall were
compared. Checklist reliability was assessed separately.
Setting
After-school programmes in the United States.
Subjects
Forty-two children (18 males, 24 females, age = 8.0 ± 0.9 years)
participated in the validation analysis and 49 children (28 males, 21
females, age = 7.5 ± 0.9 years) in the reliability analysis.
Results
No differences in mean calcium intakes were found by method or gender. The
checklist correlated well with recall among girls (r = 0.65, P = 0.01) but not
boys (r = −0.33, P = 0.19). Agreement over time was above 80%
for most foods.
Conclusion
The calcium checklist is useful for assessing calcium intake among groups of
6–10-year-old children in settings that preclude parental
assistance. More research is needed to improve accuracy among boys.
To validate a diet history questionnaire (DHQ) using a weighed food record
(WFR) as the standard method in the estimation of food consumption and
nutrient intake in a group of adults.
Design
WFR: all foods consumed by subjects during 7 consecutive days were weighed
and recorded by nutrition students. Two DHQ interviews were carried out on
days 1 (first diet history questionnaire, DHQ1) and 28 (second diet history
questionnaire, DHQ2).
Setting
Costa Rica.
Subjects
Sixty adults: 30 men and 30 women; 30 living in urban and 30 in rural
areas.
Results
In comparison to the WFR, the DHQ1 gave statistically significant higher
estimates of the mean intake of 19 nutrients for men and of three nutrients
for women. The uncorrected correlation coefficients for nutrient intake
according to both methods ranged from 0.40 to 0.83 for males and from 0.22
to 0.62 for females. Percentage of subjects classified in the same quartiles
of nutrient intake according to each method ranged from 33.3% to 63.3% for
males and from 23.3% to 53.3% for females. Misclassification in extreme
quartiles ranged from 0% to 13.3% for both sexes. The mean food group
consumption, according to the DHQ1, when compared with the WFR, gave
statistically significant differences for three of the 18 food groups for
men and for two groups in the case of women. The two applications of the DHQ
gave similar results.
Conclusion
Validation of a DHQ using a WFR as the standard method gave results that
compare favourably with those reported by other authors. This study found
important differences in the response of men and women to the DHQ: among
men, the estimates of mean nutrient intake from DHQ1 were significantly
greater than those of the WFR, while in the case of women, the mean nutrient
intake estimates from both methods were not significantly different. There
was a higher degree of correlation between the DHQ1 and the WFR mean
nutrient intakes among men than among women. The DHQ showed good
reproducibility.
To quantify factors influencing iron supplementation compliance and
haemoglobin (Hb) concentrations among pregnant women participating in an
iron supplementation programme under routine field conditions.
Design
Cross-sectional interviews and Hb measurements.
Settings
Albay and Sorsogon provinces, Bicol, Philippines.
Subjects
Three hundred and forty-six pregnant women receiving iron supplements via the
Philippine iron supplementation programme.
Results
Women had a mean Hb concentration of 10.75 ± 1.43 g
dl−1, and 56.4% were anaemic (Hb < 11.0
g dl−1). On average, the first prenatal visit occurred
at nearly 4 months (3.80 ± 1.56). The ratio of visits to number
of months pregnant was 0.51 ± 0.24. Self-reported consumption of
pills received was 85% (0.85 ± 0.23), although pill counts
suggested that consumption was 70% (0.70 ± 0.35). Using multiple
regression, an earlier first prenatal visit and greater self-reported
compliance were positively associated with Hb concentrations. Additionally,
perceived health benefits from taking the supplements and higher health
programme knowledge were positively associated with pill consumption, while
experiencing side-effects and disliking the taste of the supplements were
associated with lower pill consumption. A greater number of living children
was negatively associated with the frequency of prenatal visits. The number
of children was also directly negatively associated with Hb
concentrations.
Conclusions
Compliance was positively related to Hb concentrations. Several factors
associated with greater compliance were identified, including marital
status, number of children, health programme knowledge, side-effects,
perceived health benefits, and dislike of taste. Some of these factors may
serve as avenues for interventions to increase compliance, and ultimately Hb
concentrations.
To develop and validate a short food-frequency questionnaire to assess
habitual dietary salt intake in South Africans and to allow classification
of individuals according to intakes above or below the maximum recommended
intake of 6 g salt day−1.
Design
Cross-sectional validation study in 324 conveniently sampled men and
women.
Methods
Repeated 24-hour urinary Na values and 24-hour dietary recalls were obtained
on three occasions. Food items consumed by >5% of the sample and
which contributed ≥50 mg Na serving−1 were
included in the questionnaire in 42 categories. A scoring system was
devised, based on Na content of one index food per category and frequency of
consumption.
Results
Positive correlations were found between Na content of 35 of the 42 food
categories in the questionnaire and total Na intake, calculated from 24-hour
recall data. Total Na content of the questionnaire was associated with Na
estimations from 24-hour recall data (r =
0.750; P < 0.0001; n = 328) and urinary Na (r = 0.152; P
= 0.0105; n = 284). Urinary Na was higher
for subjects in tertile 3 than tertile 1 of questionnaire Na content
(P < 0.05). Questionnaire
Na content of <2400 and ≥2400 mg
day−1 equated to a reference cut-off score of 48 and
corresponded to mean (standard deviation) urinary Na values of 145 (68) and
176 (99) mmol day−1, respectively (P < 0.05). Sensitivity and
specificity against urinary Na ≥100 and <100 mmol
day−1 was 12.4% and 93.9%, respectively.
Conclusion
A 42-item food-frequency questionnaire has been shown to have content-,
construct- and criterion-related validity, as well as internal consistency,
with regard to categorising individuals according to their habitual salt
intake; however, the devised scoring system needs to show improved
sensitivity.
A nationwide study was performed in Cuba to assess vitamin A status and the
intake of vitamin-A-providing foods in children aged 6–11
years.
Design and subjects
The sample comprised 1191 schoolchildren from first to sixth grade, both
sexes, from municipalities randomly selected from the five eastern provinces
of Cuba in 2002 (first semester) and from the four western and four central
provinces in 2003 (first semester). A food-frequency questionnaire was
completed by 2038 mother-and-child pairs.
Results
Mean (±standard deviation) plasma retinol concentrations were 1.77
± 0.48 μmol l−1 in the western,
2.01 ± 0.56 μmol l−1 in the
central and 1.40 ± 0.41 μmol l−1
in the eastern region. No child had plasma retinol concentration below 0.35
μmol l−1, indicative of a high risk of
clinical deficiency. Subclinical deficiency, plasma retinol concentration of
0.35–0.7 μmol l−1, was seen in
<2% of subjects in all three regions and was <5% even
in the two provinces with the worst vitamin A status (Guantánamo,
4.6%; Las Tunas, 3.0%). Adequate status (>1.05 μmol
l−1) was present in >90% of subjects in
all western and central provinces, and in one of the eastern provinces
(Holguín), whereas in the four remaining eastern provinces,
adequate status was present in >75%. Only nine fruits and
vegetables were consumed frequently (>3 times per week) by
>50% of children. Thirty-seven per cent regularly consumed a
supplement containing vitamin A.
Conclusions
Most Cuban children aged 6–11 years had adequate vitamin A status.
Consumption of foods rich in vitamin and provitamin A, especially
vegetables, was frequent but limited to a small variety of foods.
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
≥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.