Testing nutrient profile models using data from a survey of nutrition professionals

OBJECTIVE: To compare nutrient profile models with a standard ranking of 120 foods. DESIGN: Over 700 nutrition professionals were asked to categorise 120 foods into one of six positions on the basis of their healthiness. These categorisations were used to produce a standard ranking of the 120 foods. The standard ranking was compared with the results of applying eight different nutrient profile models to the 120 foods: Models SSCg3d and WXYfm developed for the UK Food Standards Agency, the Nutritious Food Index, the Ratio of Recommended to Restricted nutrients, the Naturally Nutrient Rich score, the Australian Heart Foundation's Tick scheme, the American Heart Association's heart-check mark and the Netherlands tripartite classification model for foods. Rank correlation was assessed for continuous models, and dependence was assessed for categorical models. RESULTS: The continuous models each showed good correlation with the standard ranking (Spearman's rho = 0.6-0.8). The categorical models achieved high chi(2) results, indicating a high level of dependence between the nutrition professionals' and the models' categorisations (P < 0.001). Models SSCg3d and WXYfm achieved higher scores than the other models, implying a greater agreement with the standard ranking of foods. CONCLUSIONS: The results suggest that Models SSCg3d and WXYfm rank and categorise foods in accordance with the views of nutrition professionals.     

Validating a nutrient profile model

OBJECTIVE: To assess the validity of nutrient profiling Model WXYfm - developed for the purpose of regulating the promotion of 'less healthy' foods to children. The model ranks foods according to their healthiness and categorises foods into 'healthier' and 'less healthy' foods. DESIGN: Convergent and discriminant validity was tested by comparing the way Model WXYfm categorises foods with the way the UK's national food guide - the Balance of Good Health (BGH) - categorises foods. Construct validity was assessed by testing a hypothesis relating the constructs of 'healthiness' of foods (as measured by Model WXYfm) and the 'healthiness' of diets (measured using the Diet Quality Index) and assessing whether this hypothesis was confirmed or refuted by using data on the dietary patterns of subjects (n = 1117) of the National Diet and Nutrition Survey of adults carried out in Great Britain in 2000-01. RESULTS: Model WXYfm showed good convergent and discriminant validity: the level of agreement between the way the model categorises foods and the way the BGH categorises foods was good (kappa = 0.69). Model WXYfm also showed good construct validity: the energy intake from 'less healthy' foods amongst subjects with the least healthy diets was nearly twice the energy intake from 'less healthy' foods amongst the subjects with the healthiest diets. CONCLUSIONS: Model WXYfm demonstrated good validity in categorising foods in a way that is related to the healthiness of diets both recommended and achieved. The methods for assessing the validity of a nutrient profile model used in this paper have not, to our knowledge, been used before.     

What do babies eat? Evaluation of a food frequency questionnaire to assess the diets of infants aged 6 months

OBJECTIVE: To evaluate the relative validity of a food frequency questionnaire (FFQ) for assessing nutrient intakes in 6-month-old infants. DESIGN AND SETTING: The FFQ was developed to assess the diets of infants born to women in the Southampton Women's Survey (SWS), a population-based survey of young women and their offspring. The energy and nutrient intakes obtained from an interviewer-administered FFQ were compared with those obtained from a 4-day weighed diary. SUBJECTS AND METHODS: A sub-sample of 50 infants aged 6 months from the SWS had their diets assessed by both methods. The FFQ recorded the frequencies and amounts of milks, baby foods, regular foods and drinks consumed by the infants over the previous seven days. The diaries recorded the weights of all foods and drinks consumed by the infants on four separate days within 15 days following FFQ completion. RESULTS: Spearman rank correlation coefficients for intakes of energy, macronutrients and 18 micronutrients, determined by the two methods, ranged from r = 0.39 to 0.86; adjustment for energy intake tended to increase the correlation coefficients, range r(a) = 0.55 to 0.89. Bland-Altman statistics showed that mean differences between methods were in the range of -12.5% to +12.5% except for vitamin B12 (-18.9%). CONCLUSION: Although there were differences in absolute energy and nutrient intakes between methods, Spearman rank correlation coefficients indicated reasonable agreement in the ranking of intakes. The interviewer-administered FFQ is a useful tool for assessing energy and nutrient intakes of healthy infants aged about 6 months.     

Selection of food items for inclusion in a newly developed food-frequency questionnaire

OBJECTIVES: To highlight the differences between the food list required in a food-frequency questionnaire (FFQ) to rank people by their intake and the food items that contribute to absolute intake, and to discuss possible applications. METHODS: We conducted a nutritional survey among 1173 adults using an adapted 24-hour recall questionnaire. STATISTICAL ANALYSIS: To develop an FFQ, we analysed the 24-hour recall survey data by performing a stepwise multiple regression after grouping conceptually similar food items into 175 food groups. RESULTS: In total, 126 food groups were included in the developed FFQ in order to explain at least 80% of the variance in the consumption of each of 27 nutrients. The nutrients that were explained by a few food groups were vitamin A (one food group), alcohol (two), beta-carotene (two), vitamin E (three) and cholesterol (five). Nutrients that were explained by a large number of food groups were energy (37 food groups), potassium (31), magnesium (31), dietary fibre (30), phosphorus (31) and sodium (29). Using energy intake as an example, soft drinks were the best between-person energy classifiers, while providing only 2.4% of the total energy intake. Wine, seeds and nuts, which contributed highly to the variance, were minor energy contributors. In contrast, milk, sugar, fried chicken/turkey breast or whole chicken/turkey, which explained little of the variation in the population, were major energy contributors. CONCLUSIONS: Developing an FFQ on the basis of common foods may not explain the between-person variation required for ranking individual intake in diet-disease studies. Producing lists of "discriminating items" can be a useful application in developing mini-FFQs for selected nutrients.     

Traditional food diversity predicts dietary quality for the Awajún in the Peruvian Amazon

OBJECTIVE: Our goal was to assess the potential for evaluating strengths of the Awajún traditional food system using dietary assessment, a traditional food diversity score and ranking of local foods. DESIGN: The method was used for dietary data obtained from mothers and children in the Awajún culture of the Peruvian Amazon where >90% of the dietary energy is derived from local, traditional food. Traditional food diversity scores were calculated from repeat 24-hour recalls. Group mean intakes of energy, fat, protein, iron, vitamin A and vitamin C from each food item were used to rank foods by nutrient contribution. SETTING: The study took place in six remote communities along the lower Cenepa River in the Amazonas District of Peru, South America. SUBJECTS: Dietary data were collected from 49 Awajún mothers and 34 children aged 3-6 years, representative of the six communities. RESULTS: Higher traditional food diversity was associated with greater protein, fibre, vitamin and mineral intakes when controlling for energy (partial correlations = 0.37 to 0.64). Unique sources for iron, total vitamin A and vitamin C were found in the Awajún traditional food system. CONCLUSIONS: A traditional food diversity score was a useful tool for predicting nutrient adequacy for the Awajún. Promotion of the Awajún traditional food system should focus on dietary diversity and unique nutrient-dense local foods.     

Dietary intake and a food-frequency instrument to evaluate a nutrition intervention for the Apache in Arizona

OBJECTIVE: To demonstrate how dietary data collected from 24-hour dietary recalls were incorporated into the development of a quantitative food-frequency questionnaire (QFFQ) for the Apache in Arizona. DESIGN: A cross-sectional study was first conducted using 24-hour dietary recalls to identify foods for inclusion on a QFFQ that would be used to evaluate a nutrition intervention. SETTING: The White Mountain and San Carlos Apache reservations in East-central Arizona. SUBJECTS: The 24-hour dietary recalls were collected from a random sample of 53 adults (34 women and 19 men). RESULTS: A QFFQ was developed that included all foods reported by two or more respondents, plus traditional and seasonal foods. Portion size was assessed using familiar household units and culturally appropriate food models. The final instrument contains 155 foods. Frequency of consumption is assessed using eight categories ranking from 'never or less than once a month' to '2 or more times a day'. Nutrient intakes and the five major food sources of energy, fat and sugar are presented. CONCLUSION: The QFFQ developed is complete and up-to-date for assessing usual food and nutrient intake for the Apache in Arizona. The instrument will be used to evaluate a food store-based nutrition intervention to reduce risk of chronic diseases.     

Developing nutrient profile models: a systematic approach

OBJECTIVE: Nutrient profiling can be defined as the 'the science of categorising foods according to their nutritional composition'. The purpose of the present paper is to describe a systematic and logical approach to nutrient profiling. DESIGN: A seven-stage decision-making process is proposed and, as an illustration of how the approach might operate in practice, the development of a nutrient profiling model for the purpose of highlighting breakfast cereals that are 'high in fat, sugar or salt' is described. RESULTS: The nutrient profile model developed for this paper calculates scores for foods using a simple equation. It enables breakfast cereals to be compared with each other and with other foods eaten at breakfast. CONCLUSION: Nutrient profiling is not new, but hitherto most nutrient profiling models have been developed in an unsystematic and illogical fashion. Different nutrient profiling models are needed for different purposes but a key requirement should be that they are developed using a systematic, transparent and logical process. This paper provides an example of such a process; approaches to validating nutrient profiling models are described elsewhere.     

Development and simulated validation of a food-frequency questionnaire for the Colombian population

OBJECTIVE: To develop a food-frequency questionnaire (FFQ) useful for ranking of nutrient intakes. DESIGN: Subjects consuming their regular diet completed 7 days of weighed intake registry (7-WIR). Foods for the FFQ were selected by stepwise multiple regression. The FFQ was then completed for each subject using data on individual food consumption from the 7-WIR. The correlation and agreement between the extrapolated FFQ and the 7-WIR data were assessed using Spearman's rank correlation coefficients (rS) and Bland and Altman's limits of agreement (LOA). SETTING: Bucaramanga, Colombia. SUBJECTS: We studied 97 randomly selected 20-40-year-old subjects. RESULTS: Sixty foods were selected for the FFQ. The 7-WIR and the extrapolated FFQ intake estimates correlated well. rS was 0.58 for energy, 0.53 for carbohydrate, 0.50 for total fat, and 0.48 for protein. For micronutrients, rS varied from 0.46 (manganese) to 0.71 (vitamin B12). FFQ average intake estimates were 83%, 80%, 86.2% and 86.4% of 7-WIR estimates for energy, carbohydrate, total fat and protein, respectively. LOA for these nutrients ranged between 45% and 165%. FFQ micronutrient intakes were on average 96% (median) of those from the 7-WIR, and the median lower and upper LOA were 50% and 203%. However, there was no indication that the degree of agreement varied with the level of intake. CONCLUSIONS: According to our simulated validation, this FFQ may be useful to rank subjects by nutrient intake. Its validity against standard independent measurements and its applicability to other subsets of the Colombian population should be carefully considered.     

A multipurpose tool to evaluate the nutritional quality of individual foods: Nutrimap

BACKGROUND/OBJECTIVES: With obesity and nutrition-related diseases rising, public health authorities have recently insisted nutritional quality be included when advertising and labelling food. The concept of nutritional quality is, however, difficult to define. In this paper we present an innovative, science-based nutrient profiling system, Nutrimap, which quantifies nutritional assets and weaknesses of foods. METHODS: The position of a food is defined according to its nutritional composition, food category, the consumer's nutritional needs, consumption data and major public health objectives for nutrition. Amounts of each of 15 relevant nutrients (in 100 kcal) are scored according to their ability to 'rebalance' or 'unbalance' the supply in the whole diet, compared with current recommendations and intakes. These scores are weighted differently in different food categories according to the measured relevance of the category to a nutrient's supply. Positive (assets) and negative (weaknesses) scores are totalled separately. RESULTS: Nutrimap provides an overall estimate of the nutritional quality of same-category foods, enabling easy comparisons as exemplified for cereals and fruit/vegetables. Results are consistent with major nutritional recommendations and match classifications provided by other systems. Simulations for breakfasts show that Nutrimap can help design meals of controlled nutritional value. CONCLUSIONS: Combining objective scientific bases with pragmatic concerns, Nutrimap appears to be effective in comparing food items. Decision-makers can set their own limits within the Nutrimap-defined assets and weaknesses of foods and reach categorisations consistent with their objectives--from regulatory purposes to consumer information or support for designing meals (catering) or new products (food industry).     

The relationship between education and food consumption in the 1995 Australian National Nutrition Survey

OBJECTIVE: To assess the relationship between education and the intake of a variety of individual foods, as well as groups of foods, for Australian men and women in different age groups. DESIGN: Cross-sectional national survey of free-living men and women. SUBJECTS: A sample of 2501 men and 2739 women aged 18 years and over who completed the National Nutrition Survey (NNS) 1995. METHODS: Information about the frequency of consumption of 88 food items was obtained using a food-frequency questionnaire in a nation-wide nutrition survey. Irregular and regular consumers of foods were identified according to whether they consumed individual foods less than or more than once per month. The relationship between single foods and an index of education (no post-school qualifications, vocational, university) was analysed via contingency table chi-square statistics for men and women. Food group variety scores were derived by assigning individual foods to conventional food group taxonomies, and then summing the dichotomised intake scores for individual foods within each food group. Two-way analyses of variance (education by age groups) were performed on food variety scores for men and women, separately. RESULTS: While university-educated men and women consumed many individual foods more regularly than less-educated people, they were less likely to be regular consumers of several meat products. The relationship between education and food consumption was less apparent when individual food scores were aggregated into food group scores. University-educated men and women exhibited higher scores on total food group variety than the other educational groups. CONCLUSIONS: Higher education is associated with the regular consumption of a wider variety of foods. Aggregation of individual food consumption indices into food variety scores may mask the apparent effects of educational background on food consumption.     

Factors affecting food choice in Greek primary-school students: ELPYDES study

OBJECTIVE: To measure factors affecting food choice in a sample of Greek schoolchildren attending 5th and 6th grade. DESIGN: Three self-administered questionnaires were distributed to the participants - one on nutritional knowledge, one on self-efficacy and social support for dietary change and a food-frequency questionnaire. SETTING: One hundred Greek primary schools from Attica and Thessaloniki regions. SUBJECTS: In total, 2439 students in 5th and 6th grades. RESULTS: Principal components analysis was applied to extract the main factors affecting food choice of our subjects. Six components were derived explaining 66% of the total variation in factors affecting food choice. The first component was characterised by readiness to make the healthier choice when competitive foods are considered (explained variation 29%); the second was characterised by the impact of parents, friends and advertisements on students' choices and also the impact of taste, smell and cooking method on the consumption of vegetables (explained variation 11%); the third component was characterised by readiness to choose fresh foods instead of ready-to-eat, pre-packaged choices as a main meal and awareness of the health value of fruits and vegetables (explained variation 8%); the other components mainly expressed the interdependence of the main factors. CONCLUSIONS: Nutrition education and health promotion programs in Greece must include family members and activities regarding food preparation, as well as education and environmental changes in schools. Public health measures must include regulation of advertising. Moreover, the categorisation of foods as 'healthier but less tasty' and 'appealing but unhealthy' needs to be challenged in the future, since balanced nutrition is founded in variety and norm.     

Improving food provision in a Guyanese home for the elderly: a participatory approach

OBJECTIVES: To conduct a needs assessment of all aspects of food provision in a residential home and to evaluate a subsequent nutrition intervention. DESIGN: An intervention study using a before and after design. A participatory approach was adopted and quantitative and qualitative methods used throughout. The intervention involved a revised menu, kitchen equipment, and establishing wholesale shopping and food donations. SETTING: A residential home for senior citizens in Guyana. RESULTS: Meals at the home were nutritionally inadequate and deeply unpopular with the residents. Intakes of fruits and vegetables were low and the home was heavily reliant on donated soya mince and rice. Meals were served within an eight-hour period to accommodate the staff's hours of work. Cutbacks in the food budget indicated that the financial state of the home explained some of the problems. The intervention was unable to address all problems identified, but led to substantial improvements in the nutritional adequacy of the food provided following the inclusion in the menu of a number of nutrient-dense foods such as chicken liver. The new menu was acceptable to the cooks and largely popular with the residents, although some problems persisted. CONCLUSIONS: The results show that improvements in the nutrient profile of the diet could be achieved with a flexible, community-based, participatory approach that addressed all elements of a home's food provision system. The changes also proved largely popular with the residents, thus potentially contributing to their quality of life.     

Food supplementation, nutritional intake of recipients and operational aspects: an integrated pilot nutrition initiative of BRAC

OBJECTIVES: To explore the nutritional quality of supplementary foods and additional energy consumption by the recipients in a pilot nutrition initiative of BRAC. DESIGN: In-depth interviews, observations during feeding at feeding centres, and laboratory analyses of supplementary foods for nutrient contents performed at the Institute of Nutrition and Food Science, University of Dhaka, Bangladesh. SETTING: Muktagacha thana (sub-district) in Mymensingh district, a rural area of Bangladesh. SUBJECTS: Pregnant and lactating mothers and children below 2 years of age. RESULTS: Analysis revealed that supplementary food, if taken completely, could provide daily energy equivalent to 752 kcal to a mother and 212 kcal to a child below 2 years of age. Mothers consumed about 75% of the food provided (approximately 564 kcal day(-1)). The food was shared mostly with young children and husbands. In-depth interview with mothers also suggested that they usually skipped breakfast if the food was given in the morning. The children liked the taste of food, and unless the child was sick or had some food before coming to the centre, she/he ate all the food provided. Although the main purpose of the project was to provide nutrition education, it was observed that activities at feeding centres were limited to food distribution with little time devoted to the communication of nutritional messages. CONCLUSIONS: Training should be given to service providers to communicate nutritional messages effectively as part of understanding the goal of the initiative. It is important to explore whether the regular diets of the recipients are replaced by the food supplementation or not.     

The development of a healthy eating indicator shopping basket tool (HEISB) for use in food access studies-identification of key food items

OBJECTIVES: To develop an objective, nutrient-based, healthy eating indicator shopping basket (HEISB) tool for use in studies of access to healthy food. DESIGN: Tool development used a literature search to identify previous practice, web information on current definition of healthy foods by the UK Food Standards Agency, and population-based dietary surveys to identify culturally acceptable foods. These findings were then appraised with respect to practical fieldwork considerations. SETTING: The review took account of surveys undertaken in a range of geographical areas. RESULTS: Previous tools have varied in the foods selected and the rationale for inclusion. Most have considered nutritional composition but no systematic definition has been used and foods have been subjectively classified as 'less healthy' or 'more healthy'. Recent UK work on nutrient profiling enabled individual food items to be objectively assessed for inclusion. Data from national food surveys enabled commonly consumed and culturally acceptable foods to be identified. Practical considerations included item use in meals, convenience, price, and fieldwork constraints. Other issues including health and price discriminators as well as regional preferences were considered. The final HEISB tool comprised 35 items within the following categories - 17 from fruit and vegetables, nine from potatoes, bread and cereal, five from fish/meats, three from dairy, and one from fatty and sugary foods. CONCLUSIONS: The tool provides a rational basis for examining access and availability of healthy foods in cross-sectional and longitudinal retail and consumer studies.     

Exploration of possible correlates of nutrition awareness and the relationship with nutrition-related behaviours: results of a consumer study

OBJECTIVES: To unravel the concept of nutrition awareness, as it relates to risky personal nutrition-related behaviours, and to assess the sociodemographic and psychosocial correlates of nutrition awareness. DESIGN: Data were collected in a cross-sectional study with the aid of a face-to-face interview-assisted questionnaire that was based on the Precaution Adoption Process Model and Stages of Change Model. SETTING: Dutch consumer homes. SUBJECTS: Six hundred and three Dutch adults aged 18 to 80 years, selected from a panel. RESULTS: Our model explains nutrition awareness well (explained variance 53.7%). Psychosocial correlates were involvement with nutrition, health awareness, association with healthy food, perceived relevance of eating less fat, association with necessity, perceived relevance of vitamins, and perceived attributes of independent organisations. Sociodemographic correlates were gender and age. The relationship between nutrition awareness and nutrition-related behaviours proved to be very complicated. CONCLUSIONS: The value of our study is that it unravels the concept of nutrition awareness. Understanding the correlates of nutrition awareness can contribute to a more effective application of behavioural change models. Our results support increasing involvement with nutrition through personalising and tailoring to the motivational stage.     

The nutritional status of asymptomatic HIV-infected Africans: directions for dietary intervention?

OBJECTIVE: To compare the relationships between food (nutrient) intakes and biochemical markers of nutritional status of asymptomatic HIV-infected with HIV-uninfected subjects, to gain more information on the appropriate diet for HIV-infected persons at an early stage of infection. DESIGN: Cross-sectional population-based survey. SETTING: North West Province, South Africa. SUBJECTS: Two hundred and sixteen asymptomatic HIV-infected and 1550 HIV-uninfected men and women volunteers aged 15 years and older, recruited as 'apparently healthy' subjects from 37 randomly selected sites. OUTCOME MEASURES: Food and nutrient intakes, measured with a validated food-frequency questionnaire, and nutritional status indicated by anthropometric and biochemical variables, measured by a standardised methodology. RESULTS: The prevalence of HIV infection in the study population was 11.9%. The anthropometric indices and nutrient intakes of HIV-infected and uninfected subjects did not differ significantly, indicating that these 216 HIV-infected subjects were at an early stage of infection. Of the biochemical nutritional status variables, high-density lipoprotein cholesterol and total cholesterol, haemoglobin, albumin and triglycerides were significantly lower in infected subjects. They also had higher globulin and liver enzyme levels than uninfected subjects. In infected subjects, serum albumin correlated significantly with serum lipids, serum vitamin A, serum vitamin E, serum iron, total iron-binding capacity and haemoglobin. The significant positive correlations of the liver enzymes with serum lipids, albumin, vitamin A and iron, observed in HIV-uninfected subjects, disappeared in the infected subjects. Polyunsaturated fat intake showed significant positive correlations with the increased liver enzymes in infected subjects. A principal components analysis indicated that, in infected subjects, increased liver enzymes correlated with higher consumption of maize meal and lower consumption of meat and vegetables. CONCLUSIONS AND RECOMMENDATIONS: This survey indicated that asymptomatic HIV-infected subjects who followed a diet rich in animal foods had smaller decreases in serum albumin, haemoglobin and lipid variables, and smaller increases in liver enzymes, than those who consumed a diet based on staple foods. This suggests that animal foods are associated with improved nutritional status in HIV-infected persons. These results should be confirmed with intervention studies before dietary recommendations for asymptomatic HIV-infected individuals can be made.     

Separate estimates of portion size were not essential for energy and nutrient estimation: results from the Southern Community Cohort food-frequency questionnaire pilot study

OBJECTIVE: A food-frequency questionnaire (FFQ) was developed to assess habitual dietary intake in the Southern Community Cohort Study (SCCS), a prospective epidemiological study to analyse disparities in cancer and other chronic diseases between African-Americans and Whites. DESIGN: Frequency and portion size estimates were obtained for each of 104 foods. Daily intakes of 13 food groups, energy and 18 nutrients were computed. Each participant's rank and quintile classification of nutrient intakes was determined with and without the use of the subject's reported portion size. SUBJECTS: The sample was obtained from the SCCS pilot study conducted in Tennessee, Mississippi and Florida, and consisted of 209 adults, 54% African-American, with a mean (standard deviation) age of 57.1 (12.5) years. RESULTS: Correlations between the ranks from the two methods of estimation were high, ranging from 0.66 to 0.94 for food groups and 0.81 to 0.94 for nutrients. Pearson correlations were similarly high for food groups and nutrients. Concordance in exact quintile rank across the nutrient indices ranged from 52 to 70%, rising to 90-99% for concordance within adjacent quintiles. CONCLUSIONS: To reduce the respondents' burden and to increase data completeness, the assignment of a uniform portion size when scoring the SCCS FFQ was considered acceptable.     

Validation of a semi-quantitative food-frequency questionnaire used among 2-year-old Norwegian children

OBJECTIVES: An adequate diet is of profound importance in infancy and early childhood. To ensure an optimal diet, knowledge about actual intake must be obtained. The aims of this study were to assess the validity of a semi-quantitative food-frequency questionnaire (SFFQ) applied in a large nation-wide survey among 2-year-old children and to examine the validity of the SFFQ in relation to different background parameters. DESIGN: The SFFQ was administered to the parents close to the child's second birthday, and one to two weeks later they started to weigh and record the child's diet for 7 days. SUBJECTS: One-hundred and eighty-seven families with a 2-year-old child completed both methods. RESULTS: There were no differences between the intakes of protein, saturated fatty acids, total carbohydrates and calcium estimated from the two methods. The average intake of all micronutrients, except for calcium, was overestimated by the SFFQ. Bland-Altman plots showed a systematic increase in difference between the two methods with increasing intake for most nutrients. Spearman correlation coefficients between methods for nutrient intakes ranged from 0.26 to 0.50, the median correlation was 0.38. The correlations increased when estimates were adjusted for energy intake, the median correlation being 0.52. Differences in observed validity were found according to the number of siblings.CONCLUSIONS: This study indicates that the SFFQ may be a valuable tool for measuring average intakes of energy, macronutrients and several food items among a 2-year-old population in Norway. The ability of the questionnaire to rank children according to intakes of nutrients and food items was rather low.     

植物营养生物学研究方向探讨

植物营养生物学是重点研究植物活化、吸收、转运与利用养分的生理、分子及遗传机制的科学。在过去的30年,我国植物营养生物学研究取得了长足的发展,但从国家自然科学基金资助情况分析,与相关学科相比,近10多年来植物营养生物学总体研究力量相对薄弱,缺乏新一代领军人才。一些研究更接近于“纯”植物生物学,与植物营养应用研究出现脱节,对农业绿色发展及化肥产业升级的支撑不够。植物营养生物学研究者应该重视与作物育种、耕作栽培、生态环境、植物保护及化肥产业的合作,跟踪这些领域的研究现状及生产中面临的技术需求,围绕这些领域的技术“瓶颈”开展植物营养基础研究,在提供解决途径的同时创新植物营养生物学机理,从而丰富植物营养学理论。在研究内容上,建议重视控制养分响应度的生理与遗传机制,养分信号与环境信号互作,养分×土壤×管理互作及其对根系生长的影响,养分供应与抗生物胁迫,高产高效的植物营养生理学基础,特种作物的营养机理,化肥产品升级的生物学途径等方向的研究。