Strategies to promote healthier food purchases: a pilot supermarket intervention study

OBJECTIVE: To pilot the design and methodology for a large randomised controlled trial (RCT) of two interventions to promote healthier food purchasing: culturally appropriate nutrition education and price discounts. DESIGN: A 12-week, single-blind, pilot RCT. Effects on food purchases were measured using individualised electronic shopping data ('Shop 'N Go' system). Partial data were also collected on food expenditure at other (non-supermarket) retail outlets. SETTING: A supermarket in Wellington, New Zealand. PARTICIPANTS: Eligible customers were those who were the main household shoppers, shopped mainly at the participating store, and were registered to use the Shop 'N Go system. Ninety-seven supermarket customers (72% women; age 40 +/- 9.6 years, mean +/- standard deviation) were randomised to one of four intervention groups: price discounts, nutrition education, a combination of price discounts and nutrition education, or control (no intervention). RESULTS: There was a 98% follow-up rate of participants, with 85% of all reported supermarket purchases being captured via the electronic data collection system. The pilot did, however, demonstrate difficulty recruiting Maori, Pacific and low-income shoppers using the electronic register and mail-out. CONCLUSIONS: This pilot study showed that electronic sales data capture is a viable way to measure effects of study interventions on food purchases in supermarkets, and points to the feasibility of conducting a large-scale RCT to evaluate the effectiveness of price discounts and nutrition education. Recruitment strategies will, however, need to be modified for the main trial in order to ensure inclusion of all ethnic and socio-economic groups.     

Challenges in translating scientific evidence into mandatory food fortification policy: an antipodean case study of the folate-neural tube defect relationship

OBJECTIVE: To identify challenges in translating scientific evidence of a nutrient and health relationship into mandatory food fortification policy. DESIGN: A case study approach was used in which available evidence associated with the folate-neural tube defect relationship was reviewed against the Australia New Zealand Food Regulation Ministerial Council's Policy Guideline for mandatory food fortification. RESULTS: Three particular challenges were identified. The first is knowing when and how to act in the face of scientific uncertainty. The second is knowing how to address the special needs of at-risk individuals without compromising the health and safety of the population as a whole. The third is to ensure that a policy is sufficiently monitored and evaluated. CONCLUSIONS: Despite the availability of compelling evidence of a relationship between a particular nutrient and a health outcome, a definitive policy response may not be apparent. Judgement and interpretation inevitably play significant roles in influencing whether and how authorities translate scientific evidence into mandatory food fortification policy. In relation to the case study, it would be prudent to undertake a risk-benefit analysis of policy alternatives and to implement nutrition education activities to promote folic acid supplement use among the target group. Should mandatory folate fortification be implemented, comprehensive monitoring and evaluation of this policy will be essential to know that it is implemented as planned and does more good than harm. In relation to mandatory food fortification policy-making around the world, ongoing national nutrition surveys are required to complement national policy guidelines.     

Comparison between household budget survey and 24-hour recall data in a nationally representative sample of Polish households

OBJECTIVE: Household budget survey (HBS) data are used regularly for nutritional epidemiological purposes. The validity of HBS data, however, is not well established. The aim of this project was to compare HBS and individual nutrition survey (INS) data in a nationally representative sample of Polish households. DESIGN: Estimates of food consumption and nutrient intake were compared between household food acquisition data collected over 1 month and a single 24-hour recall collected from every household member in a nationally representative sample of Polish households surveyed between September and November 2000. To facilitate the comparison, INS food consumption data excluded food eaten away from home and were modified using a computer program to estimate food 'as purchased' (including disaggregation of recipe data) and to allow for wastage. SETTING: Poland. SUBJECTS: Participants were 3716 individuals in 1215 households (representing co-operation rates of 86.2% and 89.2%, respectively). RESULTS: Good agreement was shown between median estimates of foods such as potatoes, vegetables (including processed), meat, meat products and poultry, and animal fats (excluding butter), but agreement was poor for bread and rolls, fruit, vegetable fats and oils, eggs and six other food groups. Estimates of energy and nutrient intake were within +/-10% with the exceptions of polyunsaturated fats, potassium and vitamin C. CONCLUSIONS: Possible reasons for differences in findings between the two surveys include survey bias (e.g. social approval bias leading to overreporting of fruit), seasonal variations (e.g. high potato purchases between September and November) and aspects of the methodology (e.g. HBS data were based on records collected over 1 month, whereas 24-hour recall data were based on recalls collected from all household respondents on only 1 day and averaged for each household type). HBSs provide useful data for epidemiological research, but findings need to be interpreted in the light of other data regarding consumption, and numerous factors that may affect consumption need to be taken into account.     

National fortification of staple foods can make a significant contribution to micronutrient intake of South African adults

BACKGROUND: A national survey found that micronutrient deficiencies are prevalent in South African children, particularly calcium, iron, zinc, riboflavin, niacin, vitamin B6, folate, vitamin A, E and C. Mandatory fortification of maize meal and wheat flour were introduced in 2003 to combat some of the deficiencies found in children. To date however, there has not been a national survey on dietary intake in adults. OBJECTIVES: The main objectives of this study were to evaluate the micronutrient intake of the diet consumed by the average adult South African by means of secondary data analyses and secondly to evaluate the effects of fortification on selected nutrient intakes. STUDY DESIGN: Secondary data analysis was carried out with numerous dietary surveys on adults to create a database that included sampling (and weighting) according to ethnic/urban-rural residence in line with the population census, of which 79% were black Africans and the majority resided in rural areas. The effect of fortification was evaluated by substituting fortified foods in the diet for the unfortified products. SUBJECTS: The combined database used in this study comprised 3229 adults. RESULTS: Mean calcium, iron, folate and vitamin B6 intakes were very low particularly in women. Mean intakes of most micronutrients were lower in rural areas. Fortification of maize meal and wheat flour (bread) raised mean levels of thiamine, riboflavin, niacin, vitamin B6 and folate above the recommended nutrient intakes (RNIs). In women, despite fortification, mean iron intakes remained below the RNIs, as did calcium since it was not in the fortification mix. CONCLUSION: The average dietary intake of adults was of poor nutrient density, particularly in rural areas. Fortification of maize meal and wheat flour (bread) considerably improved mean vitamin B6, thiamine, riboflavin, niacin, folate and iron intakes as well as the overall mean adequacy ratio of the diet.     

Food store access and household fruit and vegetable use among participants in the US Food Stamp Program

OBJECTIVE: Recent research on access to food among low-income populations in industrialised countries has begun to focus on neighbourhood food availability as a key determinant of dietary behaviour. This study examined the relationship between various measures of food store access and household fruit and vegetable use among participants in the Food Stamp Program, America's largest domestic food assistance programme. DESIGN: A secondary data analysis was conducted using the 1996-97 National Food Stamp Program Survey. The survey employed a 1-week food inventory method, including two at-home interviews, to determine household food use. Separate linear regression models were developed to analyse fruit and vegetable use. Independent variables included distance to store, travel time to store, ownership of a car and difficulty of supermarket access. All models controlled for a full set of socio-economic variables. SUBJECTS: A nationally representative sample of participants (n=963) in the Food Stamp Program. RESULTS: After controlling for confounding variables, easy access to supermarket shopping was associated with increased household use of fruits (84 grams per adult equivalent per day; 95% confidence interval 5, 162). Distance from home to food store was inversely associated with fruit use by households. Similar patterns were seen with vegetable use, though associations were not significant. CONCLUSIONS: Environmental factors are importantly related to dietary choice in a nationally representative sample of low-income households, reinforcing the importance of including such factors in interventions that seek to effect dietary improvements.     

Identifying 'unhealthy' food advertising on television: a case study applying the UK Nutrient Profile model

OBJECTIVES: To evaluate the feasibility of the UK Nutrient Profile (NP) model for identifying 'unhealthy' food advertisements using a case study of New Zealand television advertisements. DESIGN: Four weeks of weekday television from 15.30 hours to 18.30 hours was videotaped from a state-owned (free-to-air) television channel popular with children. Food advertisements were identified and their nutritional information collected in accordance with the requirements of the NP model. Nutrient information was obtained from a variety of sources including food labels, company websites and a national nutritional database. RESULTS: From the 60 h sample of weekday afternoon television, there were 1893 advertisements, of which 483 were for food products or retailers. After applying the NP model, 66 % of these were classified as advertising high-fat, high-salt and high-sugar (HFSS) foods; 28 % were classified as advertising non-HFSS foods; and the remaining 2 % were unclassifiable. More than half (53 %) of the HFSS food advertisements were for 'mixed meal' items promoted by major fast-food franchises. The advertising of non-HFSS food was sparse, covering a narrow range of food groups, with no advertisements for fresh fruit or vegetables. CONCLUSIONS: Despite the NP model having some design limitations in classifying real-world televised food advertisements, it was easily applied to this sample and could clearly identify HFSS products. Policy makers who do not wish to completely restrict food advertising to children outright should consider using this NP model for regulating food advertising.     

Estimations of daily energy and nutrient availability based on nationally representative household budget survey data. The Data Food Networking (DAFNE) project

OBJECTIVE: To describe a cost-efficient method for estimating energy and nutrient availability using household budget survey (HBS) data. DESIGN: Four different approaches were tested and the results were compared with published nutrient intake data. The selected method was exemplarily applied in German and Greek data. SETTING: Germany, 1998; Greece, 1998/99. MATERIAL: Nationally representative HBSs. RESULTS: Comparisons showed that HBS-based estimates were generally close to intake data when results were presented as contributions to daily energy intake. Daily energy and protein availabilities were similar in Germany and Greece. Differences were observed in the availability of carbohydrates (German households reported a 5 percentage points higher contribution to daily energy availability) and lipids (Greek households recorded higher values for total fat, but lower values for saturated fat). Meat, added lipids and potatoes were important energy suppliers in Germany, whereas in Greece the first three energy suppliers were added lipids, cereals and meat. In both countries, meat, cereals, milk and cheese were important protein sources and cereals, potatoes, fruits and nuts contributed more than 60% of the daily carbohydrate availability. Added lipids were the major source of fat in the daily diet of both countries, but their contribution amounted to less than one-third in Germany and two-thirds in Greece. CONCLUSIONS: National HBS data can be used for monitoring and comparing nutrient availability among representative population samples of different countries. The ground is set for the development of a harmonised food composition table to be applied to HBS food data at international level.     

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.     

The influence of cereal and dairy consumption on the Irish diet: implications for developing food-based dietary guidelines

OBJECTIVES: To estimate the intakes of cereal and dairy products and their contribution to nutrient intakes in men and women from the Republic of Ireland with a view to formulating food-based dietary guidelines. DESIGN: The North/South Ireland Food Consumption Survey established a database of habitual food and drink consumption using a 7-day food diary. From this database all cereal and dairy products from recipes and identifiable sources were identified and a new database was generated from which analysis of the role of cereal and dairy products in the diet was carried out. RESULTS: Almost 100% of the population consumed cereal and dairy products over the course of the survey week. In general, men consumed significantly more cereal and dairy products than did women (P<0.05). Cereal products made an important contribution to the mean daily intakes of energy (26%), protein (21%), fat (13%), carbohydrate (41%), fibre (45%), iron (43%) and folate (27%). Dairy products also contributed largely to the mean daily intakes of energy (11%), protein (14%), fat (17%), calcium (48%), phosphorus (24%) and vitamin A (27%). Analysis of nutrient intakes across tertiles of cereal and dairy consumption showed that high consumers of wholemeal bread, breakfast cereals, reduced-fat milk and yoghurt had lower fat and higher carbohydrate, fibre and micronutrient intakes than low consumers of these foods. CONCLUSIONS: Findings from the present study could be used to develop effective health strategies to implement changes in cereal and dairy consumption that could alter fat, fibre and micronutrient intakes in the diet.     

Perceptions of New Zealand nutrition labels by Māori, Pacific and low-income shoppers

BACKGROUND: In New Zealand the burden of nutrition-related disease is greatest among Māori, Pacific and low-income peoples. Nutrition labels have the potential to promote healthy food choices and eating behaviours. To date, there has been a noticeable lack of research among indigenous peoples, ethnic minorities and low-income populations regarding their perceptions, use and understanding of nutrition labels. Our aim was to evaluate perceptions of New Zealand nutrition labels by Māori, Pacific and low-income peoples and to explore improvements or alternatives to current labelling systems. METHODS: Māori, Samoan and Tongan researchers recruited participants who were regular food shoppers. Six focus groups were conducted which involved 158 people in total: one Māori group, one Samoan, one Tongan, and three low-income groups. RESULTS: Māori, Pacific and low-income New Zealanders rarely use nutrition labels to assist them with their food purchases for a number of reasons, including lack of time to read labels, lack of understanding, shopping habits and relative absence of simple nutrition labels on the low-cost foods they purchase. CONCLUSIONS: Current New Zealand nutrition labels are not meeting the needs of those who need them most. Possible improvements include targeted social marketing and education campaigns, increasing the number of low-cost foods with voluntary nutrition labels, a reduction in the price of 'healthy' food, and consideration of an alternative mandatory nutrition labelling system that uses simple imagery like traffic lights.     

Food-based dietary guidelines and implementation: lessons from four countries--Chile, Germany, New Zealand and South Africa

OBJECTIVE: Food-based dietary guidelines (FBDGs) are globally promoted as an important part of national food and nutrition policies. They are presented within policy as key features of the strategy to educate the public and guide policy-makers and other stakeholders about a healthy diet. This paper examines the implementation of FBDGs in four countries: Chile, Germany, New Zealand and South Africa - diverse countries chosen to explore the realities of the FBDG within policy on public health nutrition. DESIGN: A literature review was carried out, followed by interviews with representatives from the governmental, academic and private sector in all four countries. RESULTS: In all four countries the FBDG is mainly implemented via written/electronic information provided to the public through the health and/or education sector. Data about the impact of FBDGs on policy and consumers' food choice or dietary habits are incomplete; nutrition surveys do not enable assessment of how effective FBDGs are as a factor in dietary or behavioural change. Despite limitations, FBDGs are seen as being valuable by key stakeholders. CONCLUSION: FBDGs are being implemented and there is experience which should be built upon. The policy focus needs to move beyond merely disseminating FBDGs. They should be part of a wider public health nutrition strategy involving multiple sectors and policy levels. Improvements in the implementation of FBDGs are crucial given the present epidemic of chronic, non-communicable diseases.     

Preliminary nitrogen,phosphorus, potassium,calcium and magnesium DRIS norms and indices for apple orchards in Canterbury,New Zealand

Abstract

Diagnosis and Recommended Integrated System (DRIS) norms and indices for N, P, K, Ca and Mg were developed for apple trees in Canterbury, New Zealand, based on surveys of nutrient levels of apple leaves in field experiments before and after N and K fertiliser applications and in four orchard surveys over a period of three years. Comparisons were made between calculated norms based on mean sufficiency nutrient levels and published norms. Results obtained showed that calculated norms and indices from sufficiency range provide a good indication of the order of apple nutrient requirements. High N and low Ca were identified as major nutrient problems. The best period for sampling leaves for nutrient analysis is at 3 to 5 months after blossom (i.e., December to January in New Zealand).     

Educational variations in the consumption of foods containing fat in Finland and the Baltic countries

OBJECTIVE: To examine educational differences among people who consume foods containing fat in Finland and the Baltic countries. DESIGN: Data were collected from cross-sectional postal Finbalt Health Monitor surveys that were carried out in 1998, 2000 and 2002. SETTING: Estonia, Finland, Latvia and Lithuania. SUBJECTS: For each survey, nationally representative random samples of adults aged 20-64 years were drawn from population registers (Estonia, n = 3656; Finland, n = 9354, Latvia, n = 6015; Lithuania, n = 5944). RESULTS: Differences were revealed between the countries in the consumption of foods that contain fat. Finnish people consumed butter on bread, high-fat milk, meat and meat products, and vegetable oil for cooking less frequently than people in the Baltic countries. Cheese was most popular in Finland. Educational differences in fat-related food habits were examined by applying logistic regression analysis. A positive association was found between level of education and consumption of vegetable oil used in food preparation. Drinking high-fat milk was associated with low education in all countries. People with higher education tended to consume cheese more often. Educational patterns in the consumption of butter on bread and in the consumption of meat and meat products differed between countries. CONCLUSIONS: The consumption of foods containing fat was related to educational levels in all four countries. The diet of better-educated people was closer to recommendations for the consumption of saturated and unsaturated fats than the diet of people with lower level of education. The educational gradient was more consistent in Finland than in the Baltic countries. These existing educational differences in sources of fat consumed should be taken into account in the development of national cardiovascular disease prevention programmes.     

Analysis of the temporal intake of cereal and dairy products in Irish adults: implications for developing food-based dietary guidelines

OBJECTIVES: To analyse the temporal distribution of the intake of cereal and dairy products in the Republic of Ireland. DESIGN: The North/South Ireland Food Consumption Survey established a database of habitual food and drink consumption using a 7-day food diary. The database also recorded the time and day of food consumption. Mean intakes of cereal and dairy products were calculated for time of the day and day of the week. RESULTS: At the weekend, the percentage of consumers decreased for nearly all cereal and dairy products. White bread, total cereals, full-fat milk and total dairy intakes were significantly lower at the weekend (P<0.01) compared with weekdays. Intakes of cereal and dairy products over time of the day showed clear mealtime or snacking patterns when the number of consumers was controlled for. White bread, wholemeal bread, total cereals, full-fat milk, reduced-fat milk and total dairy intakes showed mealtime peaks for morning, afternoon and evening. When examined by tertile of intake, tertile of percentage energy from fat and tertile of fibre intake, intakes of cereal and dairy products over time of the day and day of the week were similar to trends described above, regardless of the tertile. CONCLUSIONS: Temporal analysis of the intakes of cereal and dairy products did not reveal any unusual trends in this population. However, the significant methodological issues raised in this paper will be of benefit to other aspects of research in this area.     

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.     

Product variety in Australian snacks and drinks: how can the consumer make a healthy choice?

OBJECTIVE: To estimate the proportion of snack food and beverage choices available to an Australian consumer. DESIGN: A survey of product Nutrition Information Panels (NIP) and product labels on snack foods and beverages offered for sale. Data on nutrient content were compared with criteria from different nutrient profile systems to estimate the proportion of items conforming to a choice. SETTING: A large supermarket in metropolitan Melbourne, Australia. RESULTS: A consumer could choose from 1070 different snack foods and 863 different drinks. Flavour variety was more common in snacks (maximum thirteen per product) while variation in container size was more common for drinks (up to ten per product). Recommended serving size for snacks varied greatly (1822 % of snack foods presented for sale could be deemed by multiple criteria. Similarly, only 14healthyhealthier' snack foods and beverages, e.g. by reformulation of many products by the food industry and their presentation in smaller, standardised portion-size packaging.     

Trends in food availability determined by the Food and Agriculture Organization's food balance sheets in Mediterranean Europe in comparison with other European areas

OBJECTIVE: The aims of this study were to assess the changes that have occurred in food patterns in Europe over the last 40 years based on food availability data and to compare the stability of the traditional Mediterranean diet in the south of Europe in this period. DESIGN: An ecological study carried out on the basis of Food and Agriculture Organization food balance sheets for three geographical areas of Europe (Mediterranean, north and east) over two time periods: 1961-1963 and 1998-2000. The average availability of total energy, energy provided from macronutrients and food groups was calculated for each area and each period studied. RESULTS: Over the last 40 years total energy availability and energy availability from lipids have increased considerably in the three European areas, while the percentage of energy from carbohydrates has fallen. The greatest changes have occurred in Mediterranean Europe, with an increase of 20.1% in total energy availability, an increase of 48.1% in energy availability from lipids and a fall of 20.5% from carbohydrates. Moreover, Mediterranean Europe showed a significant fall in the energy supplied by cereals (29.9%) and wine (55.2%), while the contribution of milk (77.8%) and dairy products (23.6%) increased. CONCLUSIONS: The results of this study suggest that European Mediterranean countries should take nutrition policy action to maintain their traditional healthy food pattern, with a cultural added value. This implies actions at all levels, including raising awareness of consumers, collaboration with the food sector and a call to set the agenda of the concerned politicians and stakeholders.     

The role of foreign direct investment in the nutrition transition

OBJECTIVE: To examine the role of foreign direct investment (FDI) in the nutrition transition, focusing on highly processed foods. DESIGN: Data on FDI were identified from reports/databases and then compiled and analysed. A review of published literature on FDI into the food sector was conducted. SETTING: The nutrition transition is a public health concern owing to its connection with the rising burden of obesity and diet-related chronic diseases in developing countries. Global health leaders are calling for action to address the threat. Highly processed foods often have considerable fat, sugar and salt content, and warrant closer examination. RESULTS: FDI into food processing, service and retail has risen rapidly since the 1980s, mainly from transnational food companies (TFCs) in developed countries. As FDI has risen, so has the proportion invested in highly processed foods for sale in the host market. FDI has proved more effective than trade in generating sales of highly processed foods, and enables TFCs to cut costs, gain market power and obtain efficiencies in distribution and marketing. The amount of FDI targeted at developing countries is increasing; while a disproportionate share enters the larger developing economies, foreign affiliates of TFCs are among the largest companies in low- and low- to middle-income countries. The effect of FDI is to make more highly processed foods available to more people. FDI has made it possible to lower prices, open up new purchasing channels, optimise the effectiveness of marketing and advertising, and increase sales. CONCLUSION: FDI has been a key mechanism in shaping the global market for highly processed foods. Notwithstanding the role of demand-side factors, it has played a role in the nutrition transition by enabling and promoting the consumption of these foods in developing countries. Empirical data on consumption patterns of highly processed foods in developing countries are critically needed, but since FDI is a long-term investment vehicle, it is reasonable to assume that availability and consumption of highly processed foods will continue to increase. FDI can, however, bring considerable benefits as well as risks. Through its position 'upstream', FDI would therefore be an appropriate entry-point to implement a range of public health policies to 'redirect' the nutrition transition.     

Breakfast habits affect overall nutrient profiles in adolescents

OBJECTIVE: To describe breakfast consumption patterns, on a nutrient and food item level, in Belgian adolescents. DESIGN: A 7-day estimated food record was administered in a cross-sectional survey. SETTING: Secondary schools in Ghent, Belgium. SUBJECTS: A total of 341 adolescents (13-18 years old), multistage clustered sampling. RESULTS: The energy contribution of breakfast to daily energy intake was on average 15.7% in boys and 14.9% in girls. Significantly more overweight girls and significantly more girls following vocational training were categorised as eating a low-quality breakfast. In boys, the energy contribution of polysaccharides was significantly higher in consumers of good-quality breakfasts. The intake of all selected micronutrients was significantly higher in consumers of good-quality breakfasts. In girls, the total energy intake and the proportional intake of proteins and polysaccharides were significantly higher in consumers of good-quality breakfasts, while the proportional contribution of total fat, monounsaturated and polyunsaturated fatty acids was significantly lower in these girls. The intake of all micronutrients was significantly higher in girls consuming a good-quality breakfast. In all adolescents, consumers of a good-quality breakfast had significantly higher intakes of bread, fruit, vegetables, milk and milk products, and fruit juice, while intake of soft drinks was significantly lower than in consumers of low-quality breakfasts. CONCLUSIONS: Consumers of a good-quality breakfast had a better overall dietary pattern - on a nutrient and food group level - than consumers of a low-quality breakfast. A daily breakfast, including whole-grain products, fruit and (semi-) skimmed milk products or an alternative source of calcium, is recommended.     

基于区块链的农产品追溯系统信息存储模型与查询方法

针对区块链追溯系统信息数据存储负载过大、查询效率低等问题,该文以果蔬菜类农产品为例,基于Hyperledger Fabric设计了一种区块链农产品追溯信息存储模型和查询方法。提出"数据库+区块链"的链上链下追溯信息双存储设计,本地数据库存储追溯明文数据,区块链上存储追溯数据加密后的哈希值,并在此基础上建立了外联数据库索引的查询方法。通过该方法与基于key键遍历查询和批次号字段查询的2种传统区块链数据查询方法进行对比测试,结果表明当区块链追溯记录总量达到11×10~4条,批次追溯记录条数为400时,该方法查询效率分别提高了70.56%和88.66%,有效解决了区块链链式结构中数据查询效率低的问题,保证了数据隐私安全,提高了追溯信息的可靠性与时效性。