Portion Sizes (portion + size)

Distribution by Scientific Domains


Selected Abstracts


Food energy content influences food portion size estimation by nutrition students

JOURNAL OF HUMAN NUTRITION & DIETETICS, Issue 3 2010
C. C. Japur
Abstract Background:, Food portion size estimation involves a complex mental process that may influence food consumption evaluation. Knowing the variables that influence this process can improve the accuracy of dietary assessment. The present study aimed to evaluate the ability of nutrition students to estimate food portions in usual meals and relate food energy content with errors in food portion size estimation. Methods:, Seventy-eight nutrition students, who had already studied food energy content, participated in this cross-sectional study on the estimation of food portions, organised into four meals. The participants estimated the quantity of each food, in grams or millilitres, with the food in view. Estimation errors were quantified, and their magnitude were evaluated. Estimated quantities (EQ) lower than 90% and higher than 110% of the weighed quantity (WQ) were considered to represent underestimation and overestimation, respectively. Correlation between food energy content and error on estimation was analysed by the Spearman correlation, and comparison between the mean EQ and WQ was accomplished by means of the Wilcoxon signed rank test (P < 0.05). Results:, A low percentage of estimates (18.5%) were considered accurate (±10% of the actual weight). The most frequently underestimated food items were cauliflower, lettuce, apple and papaya; the most often overestimated items were milk, margarine and sugar. A significant positive correlation between food energy density and estimation was found (r = 0.8166; P = 0.0002). Conclusions:, The results obtained in the present study revealed a low percentage of acceptable estimations of food portion size by nutrition students, with trends toward overestimation of high-energy food items and underestimation of low-energy items. [source]


Timing and duration of constant light affects rainbow trout (Oncorhynchus mykiss) growth during autumn,spring grow-out in freshwater

AQUACULTURE RESEARCH, Issue 13 2009
John Taylor
Abstract Photoperiod enhancement of growth is becoming an area of increasing interest as a means of enhancing rainbow trout production efficiency in commercial practice. This paper examines the possible implications of shortening periods of constant light (LL) exposure on rainbow trout growth during autumn,spring grow-out under ambient water temperatures in freshwater to portion size. Triplicate groups of juvenile all-female rainbow trout were permanently exposed to LL in October, November, December or January. Growth was monitored and compared with those maintained under a simulated natural photoperiod (SNP) until the following May. Permanent exposure to LL (all treatments) resulted in significantly greater weight gain of rainbow trout than those under SNP. Furthermore, greatest growth was achieved when fish were left permanently exposed to LL from October. These findings suggest there may be implications for fish farmers if the period of photoperiod exposure is reduced, or timing of application is not considered with regards to ambient water temperatures. [source]


Dietary Approaches to Stop Hypertension (DASH) diet: applicability and acceptability to a UK population

JOURNAL OF HUMAN NUTRITION & DIETETICS, Issue 1 2010
K. E. Harnden
Abstract Background:, The Dietary Approaches to Stop Hypertension (DASH) diet is widely promoted in the USA for the prevention and treatment of high blood pressure. It is high in fruit and vegetables, low-fat dairy and wholegrain foods and low in saturated fat and refined sugar. To our knowledge, the use of this dietary pattern has not been assessed in a free-living UK population. Methods:, The DASH diet was adapted to fit UK food preferences and portion sizes. Fourteen healthy subjects followed the adapted DASH diet for 30 days in which they self-selected all food and beverages. Dietary intake was assessed by 5-day food diaries completed before and towards the end of the study. Blood pressure was measured at the beginning and end of the study to assess compliance to the DASH style diet. Results:, The DASH diet was easily adapted to fit with UK food preferences. Furthermore, it was well tolerated and accepted by subjects. When on the DASH style diet, subjects reported consuming significantly (P < 0.01) more carbohydrate and protein and less total fat (5%, 6% and 9% total energy, respectively). Sodium intakes decreased by 860 mg day,1 (P < 0.001). Systolic and diastolic blood pressure decreased significantly (P < 0.05) by 4.6 and 3.9 mmHg, respectively when on the DASH style diet. Conclusions:, The DASH style diet was well accepted and was associated with a decrease in blood pressure in normotensive individuals and should be considered when giving dietary advice to people with elevated blood pressure in the UK. [source]


Pesticide residues in food,acute dietary exposure,

PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 4 2004
Denis Hamilton
Abstract Consumer risk assessment is a crucial step in the regulatory approval of pesticide use on food crops. Recently, an additional hurdle has been added to the formal consumer risk assessment process with the introduction of short-term intake or exposure assessment and a comparable short-term toxicity reference, the acute reference dose. Exposure to residues during one meal or over one day is important for short-term or acute intake. Exposure in the short term can be substantially higher than average because the consumption of a food on a single occasion can be very large compared with typical long-term or mean consumption and the food may have a much larger residue than average. Furthermore, the residue level in a single unit of a fruit or vegetable may be higher by a factor (defined as the variability factor, which we have shown to be typically ×3 for the 97.5th percentile unit) than the average residue in the lot. Available marketplace data and supervised residue trial data are examined in an investigation of the variability of residues in units of fruit and vegetables. A method is described for estimating the 97.5th percentile value from sets of unit residue data. Variability appears to be generally independent of the pesticide, the crop, crop unit size and the residue level. The deposition of pesticide on the individual unit during application is probably the most significant factor. The diets used in the calculations ideally come from individual and household surveys with enough consumers of each specific food to determine large portion sizes. The diets should distinguish the different forms of a food consumed, eg canned, frozen or fresh, because the residue levels associated with the different forms may be quite different. Dietary intakes may be calculated by a deterministic method or a probabilistic method. In the deterministic method the intake is estimated with the assumptions of large portion consumption of a ,high residue' food (high residue in the sense that the pesticide was used at the highest recommended label rate, the crop was harvested at the smallest interval after treatment and the residue in the edible portion was the highest found in any of the supervised trials in line with these use conditions). The deterministic calculation also includes a variability factor for those foods consumed as units (eg apples, carrots) to allow for the elevated residue in some single units which may not be seen in composited samples. In the probabilistic method the distribution of dietary consumption and the distribution of possible residues are combined in repeated probabilistic calculations to yield a distribution of possible residue intakes. Additional information such as percentage commodity treated and combination of residues from multiple commodities may be incorporated into probabilistic calculations. The IUPAC Advisory Committee on Crop Protection Chemistry has made 11 recommendations relating to acute dietary exposure. Copyright © 2004 Society of Chemical Industry [source]


Dietary intakes of Pacific, M,ori, Asian and European adolescents: the Auckland High School Heart Survey

AUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH, Issue 1 2010
John D. Sluyter
Abstract Objective: To compare dietary intakes of European, M,ori, Pacific Island and Asian adolescents living in Auckland. Methods: A self-administered food frequency questionnaire was used to assess daily nutrient intakes of 2,549 14- to 21-year-old high-school students in Auckland (1,422 male and 1,127 female) in a cross-sectional survey carried out between 1997 and 1998. Results: Compared with Europeans, M,ori and Pacific Islanders consumed more energy per day. Carbohydrate, protein and fat intakes were higher in M,ori and Pacific Islanders than in Europeans. Cholesterol intakes were lowest in Europeans and alcohol intakes were highest in Europeans and M,ori. When nutrient intakes were expressed as their percentage contribution to total energy, many ethnic differences in nutrient intakes between Europeans and M,ori or Pacific Islanders were eliminated. After adjustment for energy intake and age, Europeans ate the fewest eggs, and Pacific Islanders and Asians ate more servings of chicken and fish, and fewer servings of milk and cereal than Europeans. Compared to Europeans, Pacific Islanders consumed larger portion sizes for nearly every food item. Conclusion: There were marked differences in nutrient intakes between Pacific, M,ori, Asian and European adolescents. Ethnic differences in food selections, frequency of food servings and portion sizes contribute to the differences in nutrient intakes between these ethnic groups. These differences generally matched those of other studies in children and adults from these ethnic groups. Implications: Interventions that reduce frequency of food consumption and serving sizes and promote less-fatty food choices in M,ori and Pacific adolescents are needed. [source]