Chizuru Nishida

Appropriate body-mass index for Asian populations and its implications for policy and intervention strategies.

to 25 kg/m 2 in different Asian populations; for high risk it varies from 26 kg/m 2 to 31 kg/m 2 . No attempt was made, therefore, to redefine cut-off points for each population separately. The consultation also agreed that the WHO BMI cut-off points should be retained as international classifications. The consultation identified further potential public health action points (23·0, 27·5, 32·5, and 37·5 kg/m 2 ) along the continuum of BMI, and proposed methods by which countries could make decisions about the definitions of increased risk for their population.A WHO expert consultation addressed the debate about interpretation of recommended body-mass index (BMI) cut-off points for determining overweight and obesity in Asian populations, and considered whether population-specific cut-off points for BMI are necessary. They reviewed scientific evidence that suggests that Asian populations have different associations between BMI, percentage of body fat, and health risks than do European populations. The consultation concluded that the proportion of Asian people with a high risk of type 2 diabetes and cardiovascular disease is substantial at BMIs lower than the existing WHO cut-off point for overweight (> or =25 kg/m2). However, available data do not necessarily indicate a clear BMI cut-off point for all Asians for overweight or obesity. The cut-off point for observed risk varies from 22 kg/m2 to 25 kg/m2 in different Asian populations; for high risk it varies from 26 kg/m2 to 31 kg/m2. No attempt was made, therefore, to redefine cut-off points for each population separately. The consultation also agreed that the WHO BMI cut-off points should be retained as international classifications. The consultation identified further potential public health action points (23.0, 27.5, 32.5, and 37.5 kg/m2) along the continuum of BMI, and proposed methods by which countries could make decisions about the definitions of increased risk for their population.

The joint WHO/FAO expert consultation on diet, nutrition and the prevention of chronic diseases: process, product and policy implications.

Nutrition Planning, Assessment and EvaluationService, Food and Nutrition Division, FAO, Rome, ItalyThe Joint WHO/FAO Expert Consultation on diet,nutrition and the prevention of chronic diseases tookplace in Geneva from 28 January to 1 February 2002. Theoverall objective of the Consultation was to review andupdate current international recommendations on diet,nutrition and the prevention of chronic diseases byevaluating the latest scientific evidence and lessonslearned from implementing national interventionstrategies to reduce the burden of these diseases. Specificobjectives included:1. Reviewing the changes in the dietary and healthpatternsworldwideandexaminingtheirrelationshiptoemergence of chronic diseases, particularly obesity,type 2 diabetes, hypertension and cardiovasculardiseases, cancer, dental disease, and osteoporosis.2. Reviewing the latest scientific evidence on therelationship between diet, nutrition and chronicdiseases.3. Examining diet, nutrition and health issues from a lifecourse perspective.4. Considering gene/nutrient interactions and theirimplications.5. Formulating recommendations concerning diet andnutrition for the prevention of chronic diseases toassist countries in developing and implementingeffective evidence-based multisectoral policies andstrategies.6. Identifying further research needs.The selection of the expert participants followed standardcriteria, including geographic and sex balance, inconsultation with regional offices. Thirty experts wereidentified,halffromdevelopingcountriesandcountriesineconomic transition where diet-related chronic diseasesare an increasing public health problem. Before beingofficially invited to participate, all were requested todeclare possible conflicts of interest to ensure the qualityand neutrality of each expert’s contributions.Four working groups composed of world-renownedexperts prepared background papers on majordiet-related chronic diseases, such as obesity, type-2diabetes,cardiovasculardiseasesandcancer,thatincludedcurrent trends for each disease, a review of the strengthand weakness of the scientific evidence linking diet anddisease, and its policy implications. Other experts wereresponsible for papers on dental diseases and osteoporo-sis while WHO staff prepared a paper on the life courseapproach and FAO staff prepared a review of the globaland regional food consumption patterns and trends.Each background paper was peer-reviewed; papers weresubmitted, together with comments by peer-reviewers(some 20 in all), to the Expert Consultation as a generalframework for discussion.Report preparationFollowinground-tableconsultationswithnongovernmen-tal organizations and industry associations in April 2002to obtain feedback on the Expert Consultation’s initialdraftreport,thedraftreportwasmadeavailableonWHO’swebsite for review and comment by all interested partiesuntil June 2002.In August 2002, the Consultation’s Chairperson, Vice-Chairperson and rapporteurs met in Geneva with theWHO/FAO secretariat members as well as with severalexpertsonphysicalactivitytoreviewmorethan120setsofcomments from governments of FAO/WHO MemberStates, representatives of the scientific community,nongovernmental organizations, commercial enterprisesandinterestedindividuals.Thesecommentswerelikewiseposted in their entirety on WHO’s website for publicscrutiny. In October 2002, several members of the ExpertConsultationmetwiththeChairpersonandtheWHO/FAOSecretariatto finalize severalpending issues. In December2002, the final draft report was sent to the members of theExpert Consultation for review and final approval. Thereport was then finalized and published in the WHOTechnical Report Series (TRS 916)

Fats and Fatty Acids in Human Nutrition: Introduction

a Nutrition and Consumer Protection Division, Food and Agriculture Organization of the United Nations (FAO), Rome, Italy; b Department of Nutrition for Health and Development, World Health Organization (WHO), Geneva, Switzerland; c Instituto de Nutricion y Tecnologia de los Alimentos (INTA), Universidad de Chile, Santiago, Chile; d Nutrition and Public Health Intervention Research Unit, London School of Hygiene & Tropical Medicine, London, UK; e Consultant, Nutrition and Consumer Protection Division, Food and Agriculture Organization of the United Nations (FAO), Rome, Italy

WHO Scientific Update on health consequences of trans fatty acids: introduction

The role of dietary fats and oils in human nutrition is one ofthe most complex and controversial areas of investigationsin nutrition science. The first expert consultation thatfocused on the topic of fats was the Joint FAO/WHO ExpertConsultation on the Role of Dietary Fats and Oils in HumanNutrition held in Rome from 21 to 30 September 1977 (FAO,1978). This consultation synthesized the state of knowledgeof dietary fats and oils in human nutrition, including nutri-tional value and both the positive and negative physiologicaleffects of different types of fats. Then the Joint FAO/WHOExpert Consultation on Fats and Oils in Human Nutritionwas held in Rome from 19 to 26 October 1993 to considerthe latest scientific evidence on many crucial and variedroles dietary fats and oils have in human nutrition andexamine the intakes of different types and levels of dietaryfats and oils and their associated health effects (FAO, 1994).The Joint WHO/FAO Expert Consultation on Diet, Nutri-tion and the Prevention of Chronic Disease held at Genevafrom 28 January to 1 February 2002 (WHO, 2003; Nishidaand Shetty, 2004) recognized that the growing epidemic ofchronic disease afflicting both developed and developingcountries was related to dietary and lifestyle changes. Duringthe past decade, rapid expansion in a number of relevantscientific fields and in the amount of population-basedepidemiological evidence has helped to clarify the role ofdiet in preventing and controlling the morbidity andpremature mortality resulting from various noncommunic-able diseases (NCDs). One of the resulting recommendationsaimed at reducing the risk of cardiovascular diseases and inpromoting cardiovascular health was that diets shouldprovide a very low intake of trans fatty acids (TFA), that is,less than 1% of total energy intake. The outcomes andrecommendations of this Expert Consultation then providedthe scientific basis for the WHO Global Strategy on Diet,Physical Activity and Health (DPAS) endorsed by the 57thWorld Health Assembly in May 2004 (WHO, 2004).

Energy balance and obesity: what are the main drivers?

PurposeThe aim of this paper is to review the evidence of the association between energy balance and obesity.MethodsIn December 2015, the International Agency for Research on Cancer (IARC), Lyon, France convened a Working Group of international experts to review the evidence regarding energy balance and obesity, with a focus on Low and Middle Income Countries (LMIC).ResultsThe global epidemic of obesity and the double burden, in LMICs, of malnutrition (coexistence of undernutrition and overnutrition) are both related to poor quality diet and unbalanced energy intake. Dietary patterns consistent with a traditional Mediterranean diet and other measures of diet quality can contribute to long-term weight control. Limiting consumption of sugar-sweetened beverages has a particularly important role in weight control. Genetic factors alone cannot explain the global epidemic of obesity. However, genetic, epigenetic factors and the microbiota could influence individual responses to diet and physical activity.ConclusionEnergy intake that exceeds energy expenditure is the main driver of weight gain. The quality of the diet may exert its effect on energy balance through complex hormonal and neurological pathways that influence satiety and possibly through other mechanisms. The food environment, marketing of unhealthy foods and urbanization, and reduction in sedentary behaviors and physical activity play important roles. Most of the evidence comes from High Income Countries and more research is needed in LMICs.

Ensuring food safety and nutrition security to protect consumer health: 50 years of the Codex Alimentarius Commission

The globalization of trade, which has contributed to food availability and diversification throughout the world, has also increased the chances that the food produced in one place will affect the health and diet of people living in another. As a result, global food safety and nutrition measures applicable across borders, institutions and disciplines, including the establishment of evidence-based international standards on food safety and nutrition, are more important than ever before. Since its inception in 1963, the Codex Alimentarius Commission has developed hundreds of such standards and provided guidance for improving food safety and nutrition in each of its member states and globally. The Commission, whose 186 members represent 99% of the world’s population, is the principal body of the Joint Food and Agriculture Organization of the United Nations (FAO)/World Health Organization (WHO) Food Standards Programme.1 In addition to international food safety and nutrition standards, it develops guidelines and codes of practice, also intended to protect consumers’ health as well as to ensure fair practices in the food trade. Its standards and related texts cover an impressively wide range of subjects of international relevance having to do with biotechnology, pesticides, pathogens, additives and contaminants, food labelling, reference values for nutrients (particularly those related to the risk of noncommunicable diseases) and many other areas. In 1995, the World Trade Organization Agreement on the Application of Sanitary and Phytosanitary Measures called on members of the World Trade Organization to harmonize their national regulations to Codex standards,2 which have since become international benchmarks for food safety. Over the decades the Commission has benefited from the scientific and technical advice provided by WHO. In collaboration with FAO, WHO has convened international meetings of experts to address emerging or emergency issues and provide independent risk assessments, and the recommendations from these meetings feed directly into the Commission’s standard-setting process. Four expert groups meet regularly: the Joint FAO/WHO Expert Committee on Food Additives has carried out risk assessments related to food additives, contaminants, natural toxins and veterinary drug residues in food since 1956; the Joint FAO/WHO Meeting on Pesticide Residues has assessed since 1963 the potential health effects of pesticide residues and recommends safe maximum residue levels for specific food commodities; the Joint FAO/WHO Expert Meeting on Microbiological Risk Assessment has focused since 2000 on risk assessments for selected pathogen–commodity combinations, and the recently-established Joint FAO/WHO Expert Meetings on Nutrition provide scientific advice on nutritional matters. Although Codex standards are sometimes viewed as “trade standards”, their primary purpose is to protect consumers’ health by ensuring the safety and nutritional quality of food products traded worldwide. The importance of this work is evidenced by the large burden of food- and diet-related disorders and illness. Foodborne and waterborne diarrhoeal diseases kill an estimated 2.2 million people annually, most of them children3 and food containing harmful levels of chemicals can cause serious health problems, including cancer. Excessive intake of calories can lead to obesity and to conditions such as diabetes mellitus, coronary heart disease, cancer, hypertension and stroke.4,5 On the other hand, lack of sufficient food and vitamin and mineral deficiencies also cause enormous numbers of deaths and disability. Stunting, a mark of chronic undernutrition, affects 165 million children younger than 5 years and an estimated 35% of all deaths among children in this age group are associated with undernutrition.6 Foodborne diseases and malnutrition undermine not only human health and productivity, but also countries’ potential for sustainable development. As the Commission celebrates 50 years of successful work, it may be a good time to reflect on its trajectory and how it can serve the public interest even better. Over the years the Commission has become more inclusive. Thanks to the work of the FAO/WHO Project and Trust Fund for Enhanced Participation in Codex, launched in 2003, more countries in development and with economies in transition are actively participating in the Commission. The openness, transparency and precision of its reporting and prioritization procedures have been improved. Nonetheless, today’s rapid changes in trade, travel and commerce call for an international standard-setting system that is able to respond more quickly to new situations. One way to achieve this might be through better use of modern information technology. Stronger support of national Codex contact points is needed as well, but equally necessary are heightened political will and an acknowledgement of the importance of food safety and nutrition in public health. Because trade, nutrition and food safety are so closely connected, closer collaboration between different sectors and strengthened interactions between the Codex and other global players will be essential.

Elaboración de valores de referencia de la OMS para el crecimiento de escolares y adolescentes

Introduction The need to develop an appropriate single growth reference for the screening, surveillance and monitoring of school-aged children and adolescents has been stirred by two contemporary events: the increasing public health concern over childhood obesity (1) and the April 2006 release of the WHO Child Growth Standards for preschool children based on a prescriptive approach. (2) As countries proceed with the implementation of growth standards for children under 5 years of age, the gap across all centiles between these standards and existing growth references for older children has become a matter of great concern. It is now widely accepted that using descriptive samples of populations that reflect a secular trend towards overweight and obesity to construct growth references results inadvertently in an undesirable upward skewness leading to an underestimation of overweight and obesity, and an overestimation of undernutrition. (3) The reference previously recommended by WHO for children above 5 years of age, i.e. the National Center for Health Statistics (NCHS)/WHO international growth reference, (4) has several drawbacks. (5) In particular, the body mass index-for-age reference, developed in 1991, (6) only starts at 9 years of age, groups data annually and covers a limited percentile range. Many countries pointed to the need to have body mass index (BMI) curves that start at 5 years and permit unrestricted calculation of percentile and z-score curves on a continuous age scale from 5 to 19 years. The need to harmonize growth assessment tools conceptually and pragmatically prompted an expert group meeting in January 2006 to evaluate the feasibility of developing a single international growth reference for school-aged children and adolescents. (7,8) The experts agreed that appropriate growth references for these age groups should be developed for clinical and public health applications. They also agreed that a multicentre study, similar to the one that led to the development of the WHO Child Growth Standards for 0 to 5 years, would not be feasible for older children, as it would not be possible to control the dynamics of their environment. Therefore, as an alternative, the experts suggested that a growth reference be constructed for this age group using existing historical data and discussed the criteria for selecting the data sets. WHO subsequently initiated a process to identify existing data sets from various countries. This process resulted in an initial identification of 115 candidate data sets from 45 countries, which were narrowed down to 34 data sets from 22 countries that met the inclusion criteria developed by the expert group. However, after further review, even these most promising studies showed great heterogeneity in methods and data quality, sample size, age categories, socioeconomic status of participating children and various other factors critical to growth curve construction. Therefore, it was unlikely that a growth reference constructed from these heterogeneous data sets would agree with the WHO Child Growth Standards at 5 years of age for the different anthropometric indicators needed (i.e. height-for-age, weight-for-age and BMI-for-age). In consequence, WHO proceeded to reconstruct the 1977 NCHS/WHO growth reference from 5 to 19 years, using the original sample (a non-obese sample with expected heights), supplemented with data from the WHO Child Growth Standards (to facilitate a smooth transition at 5 years), and applying the state-of-the-art statistical methods (9,10) used to develop standards for preschool children, that is, the Box-Cox power exponential (BCPE) method with appropriate diagnostic tools for the selection of best models. The purposes of this paper are to report the methods used to reconstruct the 1977 NCHS/WHO growth reference, to compare the resulting new curves (the 2007 WHO reference) with the 1977 NCHS/WHO charts, and to describe the transition at 5 years of age from the WHO standards for under-fives to these new curves for school-aged children and adolescents. …