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Biomedical subjects

H Greenfield

Publications and source records attributed to H Greenfield.

At least 19 recordsLinked to original sources
PubMed2003

Low body weight and its association with bone health and pubertal maturation in Chinese girls.

OBJECTIVE: To investigate the prevalence of low body weight in Beijing pubertal girls and to establish the cut-off for body mass index (BMI) for underweight for Chinese pubertal girls. DESIGN: Cross-sectional study. SETTING: Three socioeconomic areas (rural, suburban and urban) in Beijing, China. SUBJECTS: Random sample of 1214 adolescent girls aged 12-14 y from 13 middle schools. RESULTS: Using a modified Chinese reference, the rate of low body weight (BMI<18) was 32.2% (95% CI 29.6-34.8%). Compared with desirable weight girls (BMI=18-21), girls with low body weight had a lower bone age, delayed breast and pubic hair development, a lower rate of menarche, lower distal one-third radius and ulna bone mineral content (BMC), bone mineral density and bone width. Logistic regression showed that BMI was one of the predictors of one-third ulna BMC after adjustment for confounding variables. When comparing BMI<18 vs BMI=18-21, the risk of BMC being less than the median increased by 82% (odds ratio 1.82, 95% CI 1.06-3.13). Thinness and stunting rates assessed by WHO recommended cut-offs are also reported. CONCLUSIONS: High prevalence of low body weight (BMI<18) was found to be a major health problem among Beijing pubertal girls. BMI<18 is confirmed as the cut-off for delayed general growth and development for Chinese girls and for screening girls at risk of lower bone mineral status.

Adolescent↗
PubMed2002

Milk consumption and bone mineral content in Chinese adolescent girls.

A cross-sectional study of a random sample of 649 girls, aged 12-14 years (mean +/- SD: 12.9 +/- 0.6 years), in the Beijing area examined the relationship between diet and bone mineral status. Food and nutrient intakes over the past year were estimated by means of a semiquantitative food frequency questionnaire. Bone mineral content (BMC) and bone width (BW) at the distal one-third and one-tenth radius and ulna were measured by single-photon absorptiometry. Results showed Beijing pubertal girls had a low mean milk consumption (fresh and powdered milk, vitamin D-fortified milk, and yogurt) at 50 g/day (95% confidence interval [CI] 44-55 g/day whereas one-third consumed no milk at all. Mean calcium intake was 356 +/- 97 mg/day of which only 21% was provided by milk and milk products. Milk intake varied by region (rural, suburban, and urban: 9, 36, and 83 g/day, respectively, p < 0.0005) as did the proportion of milk consumers in the three areas (30%, 64%, and 91%, p < 0.0005). Bone mineral density (BMD) at the distal one-third and one-tenth radius and one-tenth ulna was positively associated with milk consumption (p < 0.05). Multiple regression analysis of BMC on foods and nutrients as well as confounding factors, including weight, bone age, Tanner stage, and School Physical Activity Score (SPAS), showed that milk intake was the only dietary factor included in the models for BMC at the four bone sites measured. The model explained 54%-65% of the variation in BMC, and milk alone accounted for up to 3.2% of the variation. Milk was the only food group with significant partial correlation with BMC. SPAS, weight, bone age, and Tanner stage each accounted for a smaller variation in BMC (<1.8%). The results indicate that milk (presumably as an integrated source of nutrients) had a beneficial effect on bone mass of Beijing pubertal girls and was a better nutritional determinant of BMC than intake of any milk nutrient alone. Promotion of milk consumption should be considered for achieving optimal bone mass in this population group.

Adolescent↗
PubMed2001

Vitamin D deficiency and associated factors in adolescent girls in Beijing.

BACKGROUND: Several locally published reports indicate a high prevalence of vitamin D deficiency among adolescents in China, but no systematic population-based survey has been conducted. OBJECTIVE: The objective was to determine the prevalence of vitamin D deficiency and to study associated factors in adolescent girls in Beijing. DESIGN: A cross-sectional study was conducted in a random sample of 1248 Beijing girls aged 12-14 y. Nutrient intakes, ultraviolet light exposure, anthropometric characteristics, physical activity, signs and symptoms of rickets, and plasma concentrations of 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, and calcium were measured and X-rays of the hand and wrist were taken. RESULTS: The prevalence of clinical vitamin D and calcium deficiency (plasma 25-hydroxyvitamin D <12.5 nmol/L, plasma calcium <2.25 mmol/L, and muscle spasm at least once per week) was 9.4% in winter. The prevalence of subclinical vitamin D deficiency (25-hydroxyvitamin D <12.5 nmol/L) was 45.2% in winter and 6.7% in summer (P < 0.0005). Logistic regression analysis showed that subclinical and clinical vitamin D deficiency in winter were associated with low plasma 25-hydroxyvitamin D concentrations (<12.5 nmol/L) in summer, low calcium intake ( x +/- SD: 280 +/- 48 compared with 440 +/- 61 mg/d), and low plasma calcium concentrations (<2.25 mmol/L) in winter. The odds ratios for these associations were 3.1, 1.5, and 1.5, respectively. CONCLUSIONS: Subclinical vitamin D deficiency was widespread among Beijing adolescent girls in winter. Low plasma 25-hydroxyvitamin D concentrations in summer, low calcium intake, and low plasma calcium concentrations in winter were the main risk factors for vitamin D deficiency in winter.

Adolescent↗
PubMed2000

Quantitative determination of isoflavones and coumestrol in soybean by column liquid chromatography.

Four different stationary phases and a variety of solvents in varying proportions were examined in this study. Daidzein, genistein, formononetin, biochanin A and coumestrol were separated within 24 min on a phenyl column with acetonitrile-water (33:67, v/v) as eluent. The proposed method showed an acceptable repeatability with a RSD of quantitation <6%. The mean recoveries of daidzein, genistein, formononetin, biochanin A and coumestrol from soybean ranged from 89 to 104%. The identity of the individual analytes was confirmed by LC-MS-MS. The four isoflavones and coumestrol were isolated from soybean by hydrolysis with acid and heat. Neutralization of the soybean samples prior to identification did not alter the concentration of daidzein and genistein in soybean.

Chromatography, Liquid↗
PubMed1994

Principal sources of dietary fat in Australia: evidence from apparent consumption data and the national dietary survey of adults.

The present study evaluates the evidence about the principal sources of fat in the Australian diet from the national per capita food supply data (apparent consumption; AC) and the national dietary survey of 6255 adults aged 25 to 64 years (NDSA). The AC and the NDSA data were converted to, and expressed on, an equivalent food basis to allow appropriate comparisons of foods consumed, and food sources of dietary fat. The AC figures showed that the principal sources of fat nationally were meat, edible fats, fat spreads and oils, and milk and milk products. As an estimate of adult food consumption the AC underestimated beef and veal, lamb, total meat, and poultry consumption by 41, 10, 29 and 13% respectively, and overestimated offal, milk and milk products, and fats and oils by 15, 61, 20, and 29% respectively. The AC data rated fat spreads and cooking fats as providing more of the fat in the adult diet than did the NDSA, both in terms of total fat and fat as a percentage of energy. Conversely, on this same basis, the AC underrated meats as sources of fat in the adult diet. Other foods were of similar importance as sources of dietary fat in both sets of data. The AC markedly underestimated adult fat intake at 32% of energy compared with the NDSA result of 37%. These results have implications for epidemiological research and for the development of food and nutrition policy and programmes in Australia and similar countries.

Adult↗
PubMed1984

Sodium and potassium contents of salts, salt substitutes, and other seasonings.

Samples of table, cooking, rock and sea salts, flavoured salts, salt substitutes, seasonings, and monosodium glutamates were analysed for sodium and potassium content. The average sodium content of table, cooking and rock salts was about 16 600 mmol/kg, and that of sea salt was only marginally lower at about 16 100 mmol/kg. Flavoured salts contained about 11 900 mmol/kg, while "low salt" products contained about 9400 mmol/kg. Products marketed as containing "no salt" contained less than 20 mmol/kg (equivalent to less than 0.1 g sodium chloride per 100 g); all other salts contained the equivalent of over 50% sodium chloride. Nomenclature of seasonings was no indication of the sodium content, which ranged from 1060 to 12 960 mmol/kg. The monosodium glutamates contained 5300 mmol sodium per kg. Potassium was present at nutritionally significant levels only in "no salt" (12 800 mmol/kg) and "low salt" products (5300 mmol/kg).

Condiments↗
PubMed1984

Influence of multi-holed shakers on salting on food.

In a study of 2241 Australian adults consuming main meals at a cafeteria, single-and multi-holed (5, 9, 13) salt shakers were weighed before and after use. For all hole numbers, salt use increased linearly with an increase in hole area to a maximum value of 1.1-1.2 g which was the same irrespective of hole number. For a given hole area multi-holed shakers decreased salt use compared with single-holed shakers suggesting that multi-holed shakers are easier for consumers to control. However the greatest restriction in salt use (0.37 g per meal) is obtained by use of a single-holed shaker of 3 mm2 hole area.

Australia↗
PubMed1984

Contributions of foods to sodium in the Australian food supply.

The sodium contributions of various foods in the Australian supply have been calculated by applying recent local food composition data to food availability data and to typical notional Australian diets. Sodium available for consumption from the food supply was 3.00 g per capita per day. Of foods which are salted during processing, the three heaviest contributors of sodium were bread (23 per cent of total available sodium), processed meat and fish (14 per cent), and margarine (8 per cent). Other important contributors were breakfast cereals, biscuits, cheese, butter, potato crisps, dried soups and cakes (including pastries, pies and puddings). Foods identified by health authorities as 'highly salted' and thus prime targets for reduced consumption, provided 33 per cent of total available sodium, less than the 50 per cent contributed by other foods salted during processing. Take-away foods per se did not contribute more sodium than processed foods generally.

Adolescent↗
PubMed1984

Salting of take-away foods at point of purchase.

Sodium and potassium levels were determined in ten types of fried take-away foods and sandwiches purchased from retail outlets with and without the addition of salt by the food handler. In virtually all foods the major source of sodium was that added during manufacture of the food ingredients rather than that added by the food preparer.

Food↗
PubMed1983

Salting of food--a function of hole size and location of shakers.

The establishment of an association between hypertension and the level of sodium in the diet has focused interest in many countries on the amount of salt added to food, with estimates of intake in western countries being in the range 6-14 g per person per day. As a result, many health authorities have advocated a decrease in salt consumption by the population in general, a common suggestion for achieving a meaningful reduction being to limit the amount of salt used at the table. It is generally assumed that salting habits are influenced by taste preference as shaped by socio-cultural determinants. However, from our observations of the rate of discretionary salt usage of over 1,900 people (mainly adults) consuming main meals in public institutions in Sydney, Australia, were suggest that salting is strongly influenced by the physical factor of mode of presentation of salt to the consumer, particularly the hole size of the salt shaker, and is not influenced by demographic variables.

Australia↗
PubMed1983

Birthweights in Goroka and Kainantu Hospitals.

Birthweight data for 4474 live, healthy, singleton, full-term births of 2000g or over were analysed. The mean birthweights were 3136 +/- 445g at Goroka, and 3106 +/- 473g at Kainantu. Birthweights varied with sex, region of maternal origin, season and birth order, but not with year. Significant influences on Goroka birthweight values were, in order of importance, birth order, sex and season.

Birth Order↗
PubMed1983

Liquid chromatography, microfluorometry, and dye-titration determination of vitamin C in fresh fruit and vegetables.

The vitamin C content of several fresh fruit and vegetables was determined by a liquid chromatographic (LC) method which gave simultaneous separate values for ascorbic acid and dehydroascorbic acid (DHA) and by the official AOAC methods of microfluorometry and dye-titration. The levels of ascorbic acid obtained by LC and dye-titration were in good agreement, except for a few colored products where it was difficult to determine the end point of the titration. The combined values for ascorbic acid and DHA obtained by LC and microfluorometry were in agreement for most produce, but for about one-third of the samples, the values obtained by microfluorometry were significantly higher.

Ascorbic Acid↗
PubMed1982

Sodium and potassium levels in Australian processed foods.

We analysed 118 foods available in retail outlets in Sydney for their sodium and potassium content. The concentration of sodium in the types of food examined was (from highest to lowest); salami, ham, luncheon meat, corned beef, liverwurst, breakfast cereals, cracker biscuits, frankfurters, cheese, crispbread, bread, sweet biscuits, canned vegetables, cheesecake and frozen vegetables. There were large variations within some of these groups, especially cheese and breakfast cereals. We have summarized data recently published on 250 other foods. The concentration of potassium was highest in bran-based breakfast cereals and lowest in cheese.

Australia↗