Factors influencing women's choice of weight-loss diet

We developed a typology of eight minimally overlapping weight-loss diet methods and used it to survey 151 women dieters on their choice of diet in the previous 12 months, their motivations to diet, and their eating disorder symptomatology. Canonical correlations revealed a potentially problematic "thin, quick, and easy" association of methods and motives, as well as a more healthful "thin, natural, life-style" association. Both featured the pursuit of thinness but not health. In fact, health was rated by dieters as the poorest motivator of dieting. The results highlight the importance to women dieters of short-term aesthetic concerns over long-term health.

Diet and hypertension in the Asia-pacific region : a brief review

In this paper, the possible reasons for the prevalence of hypertension in the Asia–Pacific region are examined, along with its likely dietary, nutritional and sociocultural causes. This brief survey indicates the need for more comprehensive blood pressure monitoring and surveillance throughout the region. Findings from research conducted in the region and elsewhere suggest that a variety of aetiological factors predict the occurrence of hypertension, most of which are similar to those observed in western populations. However, several lines of research suggest that obesity, abdominal obesity and a number of dietary constituents, in addition to salt, may play relatively greater roles than in western populations. It is argued that hypertension may be prevented via a combination of individual, community and governmental approaches which promote social capital, environmentally sustainable food production and the public health.

Exercise, diet and skeletal muscle gene expression

Skeletal muscle, as a consequence of its mass and great capacity for altered metabolism, has a major impact on whole-body metabolic homeostasis and is capable of remarkable adaptation in response to various physiological stimuli, including exercise and dietary intervention. Exercise-induced increases in skeletal muscle mRNA levels of a number of genes have been reported, due to transcriptional activation and/or increased mRNA stability. The cellular adaptations to exercise training appear to be due to the cumulative effects of transient increases in gene transcription after repeated exercise bouts. The relative importance of transcriptional (mRNA synthesis) and translational (mRNA stability or translational efficiency) mechanisms for the training-induced increases in skeletal muscle protein abundance remains to be fully elucidated. Dietary manipulation, and the associated alterations in nutrient availability and hormone levels, can also modify skeletal muscle gene expression, although fewer studies have been reported. A major challenge is to understand how exercise and diet exert their effects on gene and protein expression in skeletal muscle. In relation to exercise, potential stimuli include stretch and muscle tension, the pattern of motor nerve activity and the resultant calcium transients, the energy charge of the cell and substrate availability, oxygen tension and circulating hormones. These are detected by various cellular signaling mechanisms, acting on a range of downstream targets and a wide range of putative transcription factors. A key goal in the years ahead is to identify how alterations at the level of gene expression are coupled to the changes in skeletal muscle phenotype. It is clear that gene expression, although representing a specific site of regulation, is only one step in a complex cascade from the initial stimulus to the final phenotypic adaptation and integrated physiological response.

Constipation and diet in a community sample of older Australians

Objective: To estimate the prevalence of constipation and laxative use in a sample of people 65 years and over and examine relationships between usual diet and constipation.
Design: A mailed survey using validated instruments to measure bowel habit and laxative use with follow-up interviews to collect dietary data.
Subjects and setting: Three hundred and thirty people aged 65 years and over living at home in Melbourne were randomly selected from the electoral roll of a federal electorate.
Statistical analysis: Descriptive statistics, frequencies and two sample t-tests were used.
Results: Seventy-nine people responded to the mailed bowel survey and 61 were interviewed to collect food intake data. The proportion of constipated people was approximately one quarter (n = 18). Laxative use in the previous 12 months was reported by a fifth of respondents and in these subjects one in four was not constipated. Analysis of the dietary data revealed that the average number of cereal and vegetable serves consumed per day was similar to the national average but less than recommended by nutrition bodies although fruit intake met these recommendations. Constipated subjects consumed fewer serves from the cereals food group than those who were not constipated (2.9 and 3.5 serves respectively, P = 0.03).
Conclusion: Constipation and laxative use appears to be as common in older Australians as in similar populations overseas. Low intake of cereal foods may be a contributing factor.

Benefits and barriers to the consumption of a vegetarian diet in Australia

Objective: The aim of this study was to examine consumers' perceived benefits and barriers to the consumption of a vegetarian diet.

Design: Survey (written questionnaire) that included questions on perceived benefits and barriers to the consumption of a vegetarian diet.

Setting: South Australia.

Subjects: Six hundred and one randomly selected South Australians.

Results: The main perceived barriers to adopting a vegetarian diet were enjoying eating meat and an unwillingness to alter eating habits. This was the case for men, women and all age groups, although there were sex and age differences present in over half of the barrier items. For example, family food preferences were a greater problem for women than for men, while the oldest group was more likely to agree that humans are ‘meant’ to eat meat than the younger groups. The main benefits associated with vegetarian diets were health benefits: increased fruit and vegetable intake, decreased saturated fat intake, weight control. Animal welfare-related benefits and disease prevention were also important. Age and sex differences were apparent, although age differences were more important than sex differences.

Conclusions: The majority of respondents perceived there to be health benefits associated with the consumption of a vegetarian diet, but also, predictably, enjoyed eating meat. Given this, it is likely that interest in plant-based diets that contain some meat is higher than that in no-meat diets. An understanding of the perceived benefits and barriers of consuming a vegetarian diet will allow the implementation of strategies to influence meat and vegetarianism beliefs, dietary behaviour and, hence, public health.

A short-term, high-fat diet up-regulates lipid metabolism and gene expression in human skeletal muscle

Background: Dietary fatty acids may be important in regulating gene expression. However, little is known about the effect of changes in dietary fatty acids on gene regulation in human skeletal muscle.
Objective: The objective was to determine the effect of altered dietary fat intake on the expression of genes encoding proteins necessary for fatty acid transport and ß-oxidation in skeletal muscle.
Design: Fourteen well-trained male cyclists and triathletes with a mean (± SE) age of 26.9 ± 1.7 y, weight of 73.7 ± 1.7 kg, and peak oxygen uptake of 67.0 ± 1.3 mL ˙ kg-1 ˙ min-1 consumed either a high-fat diet (HFat: > 65% of energy as lipids) or an isoenergetic high-carbohydrate diet (HCho: 70–75% of energy as carbohydrate) for 5 d in a crossover design. On day 1 (baseline) and again after 5 d of dietary intervention, resting muscle and blood samples were taken. Muscle samples were analyzed for gene expression [fatty acid translocase (FAT/CD36), plasma membrane fatty acid binding protein (FABPpm), carnitine palmitoyltransferase I (CPT I), ß-hydroxyacyl-CoA dehydrogenase (ß-HAD), and uncoupling protein 3 (UCP3)] and concentrations of the proteins FAT/CD36 and FABPpm.
Results: The gene expression of FAT/CD36 and &szlig; -HAD and the gene abundance of FAT/CD36 were greater after the HFat than after the HCho diet (P < 0.05). Messenger RNA expression of FABPpm, CPT I, and UCP-3 did not change significantly with either diet.
Conclusions: A rapid and marked capacity for changes in dietary fatty acid availability to modulate the expression of mRNA-encoding proteins is necessary for fatty acid transport and oxidative metabolism. This finding is evidence of nutrient-gene interactions in human skeletal muscle.

Decreasing dietary sodium while following a self-selected potassium-rich diet reduces blood pressure

Reducing dietary sodium reduces blood pressure (BP), a major risk factor for cardiovascular disease, but few studies have specifically examined the effect on BP of altering dietary sodium in the context of a high potassium diet. This randomized, crossover study compared BP values in volunteer subjects self-selecting food intake and consuming low levels of sodium (Na+; 50 mmol/d) with those consuming high levels of sodium (> or =20 mmol/d), in the context of a diet rich in potassium (K+). Sodium supplementation (NaSp) produced the difference in Na+ intake. Subjects (n = 108; 64 women, 44 men; 16 on antihypertensive therapy) had a mean age of 47.0 ± 10.1 y. Subjects were given dietary advice to achieve a low sodium (LS) diet with high potassium intake (50 mmol Na+/d, >80 mmol K+/d) and were allocated to NaSp (120 mmol Na+/d) or placebo treatment for 4 wk before crossover. The LS diet decreased urinary Na+ from baseline, 138.7 ± 5.3 mmol/d to 57.8 ± 3.8 mmol/d (P < 0.001). The NaSp treatment returned urinary Na+ to baseline levels 142.4 ± 3.7 mmol/d. Urinary K+ increased from baseline, 78.6 ± 2.3 to 86.6 ± 2.1 mmol/d with the LS diet and to 87.1 ± 2.1 mmol/d with NaSp treatment (P < 0.001). The LS diet reduced home systolic blood pressure (SBP) by 2.5 ± 0.8 mm Hg (P = 0.004), compared with the NaSp treatment. Hence, reducing Na+ intake from 140 to 60 mmol/d significantly decreased home SBP in subjects dwelling in a community setting who consumed a self-selected K+-rich diet, and this dietary modification could assist in lowering blood pressure in the general population.

Diet, nutrition and the prevention of excess weight gain and obesity

Objective: To review the evidence on the diet and nutrition causes of obesity and to recommend strategies to reduce obesity prevalence.
Design: The evidence for potential aetiological factors and strategies to reduce obesity prevalence was reviewed, and recommendations for public health action, population nutrition goals and further research were made.
Results: Protective factors against obesity were considered to be: regular physical activity (convincing); a high intake of dietary non-starch polysaccharides (NSP)/fibre (convincing); supportive home and school environments for children (probable); and breastfeeding (probable). Risk factors for obesity were considered to be sedentary lifestyles (convincing); a high intake of energy-dense, micronutrient-poor foods (convincing); heavy marketing of energy-dense foods and fast food outlets (probable); sugar-sweetened soft drinks and fruit juices (probable); adverse social and economic conditions—developed countries, especially in women (probable).
A broad range of strategies were recommended to reduce obesity prevalence including: influencing the food supply to make healthy choices easier; reducing the marketing of energy dense foods and beverages to children; influencing urban environments and transport systems to promote physical activity; developing community-wide programmes in multiple settings; increased communications about healthy eating and physical activity; and improved health services to promote breastfeeding and manage currently overweight or obese people.
Conclusions: The increasing prevalence of obesity is a major health threat in both low- and high income countries. Comprehensive programmes will be needed to turn the epidemic around.

Resistant starch in the Australian diet

We set out to estimate resistant starch (RS) intakes using the 24-hour food intake data from the 1995 National Nutrition Survey (NNS) database of 13 858 Australians. As there are often significant differences in the RS content of foods reported by various authors. we calculated intakes based on both published maximum and minimum value, for individual food,. RS intakes (mean and SEM) for all persons were in the range 3.4 ± 0.03 g/d (minimum estimate) to 9.4 ± 0.07 g/d (maximum estimate). Adult males (19+ years) consumed more RS (10.7 ± 0.11 g/day maximum estimale) than adult females (19+ years) (8.2 g ± 0.08 g/day maximum estimate). RS comprised a greater proportion of the total starch intake in the very young and in the older age groups. Across the population. foods contributing most to RS intake were potatoes, bananas and white bread.

Spatial, temporal and size-class variation in the diet of estuary perch (Macquaria colonorum) in the Hopkins River, Victoria, Australia

The dietary importance of prey of estuary perch (Macquaria colonorum; Percicthyidae: Günther) was examined spatially, temporally and among size classes. Fish were collected from the Hopkins River, south-western Victoria, from September 1998 to February 1999. The species is a euryhaline, euryphagic carnivore with spatial, temporal and size class variations in diets. Fish caught from estuarine locations consumed primarily Paratya australiensis (40% IRI) while freshwater fish consumed mostly Tricopteran larvae (63.5% IRI). In both freshwater and estuarine locations, the relative importance of P. australiensis decreased with increasing length of fish. Diet changed seasonally, indicating opportunistic changes in prey. The species selected particular prey items relative to environmental availability (P. australiensis, Amarinus lacustrine).

Consumers' readiness to eat a plant-based diet

Objective: The aim of this study was to examine consumers' readiness to change to a plant-based diet. Design: Mail survey that included questions on readiness to change, eating habits and perceived benefits and barriers to the consumption of a plant-based diet. Setting: Victoria, Australia. Subjects: A total of 415 randomly selected adults. Results: In terms of their readiness to eat a plant-based diet, the majority (58%) of participants were in the precontemplation stage of change, while 14% were in contemplation/preparation, and 28% in action/maintenance. Those in the action/maintenance stage ate more fruit, vegetables, nuts, seeds, whole-meal bread, and cooked cereals than those in earlier stages. There were statistically significant differences in age and vegetarian status between the stages of change, but not for other demographic variables. There were strong differences across the stages of change with regard to perceived benefits and barriers to plant-based diets. For example, those in action/maintenance scored highest for benefit factors associated with well-being, weight, health, convenience and finances, whereas those in the precontemplation stage did not recognise such benefits. Conclusions: These findings can be utilised to help provide appropriate nutrition education and advertising, targeted at specific stages of change. For example, education about how it is possible to obtain iron and protein from a plant-based diet and on the benefits of change, in addition to tips on how to make a gradual, easy transition to a plant-based diet, could help progress precontemplators to later stages.

A preliminary examination of the diet and feeding of sea sweep Scorpis aequipinnis (Pisces: Scorpididae) from coastal waters of south-western Victoria, Australia

The diet and feeding of sea sweep (Scorpis aequipinnis) was investigated from 230 specimens collected from the south-western Victorian coastline between January and July, 2002. Stomach content analysis indicated that S. aequipinnis are browsing omnivores (55.6% algae, 25.4% animal, by dry weight), with rhodophytes found to be the most important component of their diet (93.5% frequency of occurrence; 42.6% dry weight; 45.5% prey-specific abundance). However, the relative proportions of the major dietary components differed significantly between size classes. The dietary composition of small individuals ( < 150 mm total length) was significantly different to larger individuals, primarily due to a higher degree of carnivory exhibited by the smaller fish. S. aequipinnis were found to be highly flexible feeders exploiting both benthic and pelagic food resources, characterised by irregular periods of selective carnivorous feeding.