Feeding the Worlth Healthily: the Challenge of Measuring the effects of Agriculture on Health

Agricultural production, food systems and population health are intimately linked. While there is a strong evidence base to inform our knowledge of what constitutes a healthy human diet, we know little about actual food production or consumption in many populations and how developments in the food and agricultural system will affect dietary intake patterns and health. The paucity of information on food production and consumption is arguably most acute in low- and middle-income countries, where it is most urgently needed to monitor levels of under-nutrition, the health impacts of rapid dietary transition and the increasing ‘double burden’ of nutrition-related disease. Food availability statistics based on food commodity production data are currently widely used as a proxy measure of national-level food consumption, but using data from the UK and Mexico we highlight the potential pitfalls of this approach. Despite limited resources for data collection, better systems of measurement are possible. Important drivers to improve collection systems may include efforts to meet international development goals and partnership with the private sector. A clearer understanding of the links between the agriculture and food system and population health will ensure that health becomes a critical driver of agricultural change

Determinants of appetite ratings: the role of age, gender, BMI, physical activity, smoking habits, and diet/weight concern

Appetite measures are often recorded by visual analogue scales (VAS), and are assumed to reflect central nervous system (CNS) perceptions and sensations. However, little is known about how physiological, psychological, social, and cultural factors influence VAS.To investigate whether age, gender, body mass index (BMI), smoking habits, physical activity, diet behaviour, and menstruation cycle are determinants of appetite ratings.We investigated appetite ratings in different groups of a population during a single meal test, including 178 healthy women (98) and men (80), aged 20–60 years with a BMI of 18.5–35.0 kg/m2. Subjects consumed an evening meal composed to meet individual requirements of energy content and recommendations regarding macronutrient composition. Before and every half hour until 3 hours after the meal, subjects filled out VAS for satiety, fullness, hunger, and prospective food intake. They also filled in a questionnaire on eating/slimming behaviour.Multiple linear regression analyses showed that gender and age were the most powerful predictors of postprandial satiety (p<0.001, adj. R 2=0.19) and hunger (p<0.001, adj. R 2=0.15). Repeated measures general linear model (GLM) analyses revealed that women felt more satisfied than men (p<0.001) and older subjects felt more satisfied than younger (p<0.01). Furthermore, light/no exercisers felt more satisfied and less hungry than hard/moderate exercisers (p<0.05), but these differences disappeared after adjusting for age and gender. Smokers rated their prospective consumption lower than non-smokers (p < 005) and women in the ovulation phase felt less hungry than women in the menstruation phase (p<005). Neither BMI nor diet/weight concern were significantly associated with appetite ratings.Appetite ratings differed according to age, gender, and physical activity and to a lesser degree for smoking habits and menstruation cycle. Appetite ratings were not influenced by BMI and diet/weight concern. These factors should be considered when planning studies and analysing data concerning appetite sensations

Cost of the Diet: a method and software to calculate the lowest cost of meeting recommended intakes of energy and nutrients from local foods

Background When food is available, the main obstacle to access is usually economic: people may not be able to afford a nutritious diet, even if they know what foods to eat. The Cost of the Diet method and software was developed to apply linear programming to better understand the extent to which poverty may affect people’s ability to meet their nutritional specifications. This paper describes the principles of the method; the mathematics underlying the linear programming; the parameters and assumptions on which the calculations are based; and then illustrates the output of the software using examples taken from assessments. Results The software contains five databases: the energy and nutrient content of foods; the energy and nutrient specifications of individuals; predefined groups of individuals in typical households; the portion sizes of foods; and currency conversion factors. Data are collected during a market survey to calculate the average cost of foods per 100 g while focus group discussions are used to assess local dietary habits and preferences. These data are presented to a linear programming solver within the software which selects the least expensive combination of local foods for four standard diets that meet specifications for: energy only; energy and macronutrients; energy, macronutrients and micronutrients; and energy, macronutrients and micronutrients but with constraints on the amounts per meal that are consistent with typical dietary habits. Most parameters in the software can be modified by users to examine the potential impact of a wide range of theoretical interventions. The output summarises for each diet the costs, quantity and proportion of energy and nutrient specifications provided by all the foods selected for a given individual or household by day, week, season and year. When the cost is expressed as a percentage of income, the affordability of the diet can be estimated. Conclusions The Cost of the Diet method and software could be used to inform programme design and behaviour change communication in the fields of nutrition, food security, livelihoods and social protection as well as to influence policies and advocacy debates on the financial cost of meeting energy and nutrient specifications

Measuring Malnutrition

Summary The nutritional condition of an individual, or the extent of malnutrition in a population, can be measured either in terms of outcomes , i.e. current status, or in terms of inputs , i.e rates of consumption of nutrients and/or energy in diets. A review of the methods of measurement in common use for these two approaches, and of their technical limitations, is followed by an account of the problems of interpretation of these in the light of contemporary ideas about the causes of growth faltering in children. Also discussed is the basis for standards of normality for growth and for nutrient intake levels, and the extent to which adaptive changes in behaviour or physiology may compensate for low levels of intake. It is concluded that, provided these problems are recognised, nutritional indicators can play a useful role in assessing overall food and health situations, particularly when accompanied by other complementary measurements of the effects of the health environment of the households and their social and economic characteristics

Year-round high physical activity levels in agropastoralists of Bolivian Andes: Results from repeated measurements of DLW method in peak and slack seasons of agricultural activities

By the repeated use of the doubly labeled water method (DLW), this study aimed to investigate (1) the extent of changes in energy expenditure and physical activity level (PAL) in response to increased agricultural work demands, and (2) whether the seasonal work demands induce the changes in the fairly equitable division of work and similarity of energy needs between men and women observed in our previous study (Phase 1 study; Kashiwazaki et al., 1995: Am J Clin Nutr 62: 901–910). In a rural small agropastoral community of the Bolivian Andes, we made the follow-up study (Phase 2, 14 adults; a time of high agricultural activity) of the Phase 1 study (12 adults; a time of low agricultural activity). In the Phase 2 study, both men and women showed very high PAL (mean±SD), but there was no significant difference by sex (men; 2.18 ± 0.23 (age; 64 ± 11 years, n = 7), women; 2.26 ± 0.25 (63 ± 10 years, n = 7)). The increase of PAL by 11% (P = 0.023) in the Phase 2 was equally occurred in both men and women. The factorial approach underestimated PAL significantly by ≈15% (P < 0.05). High PAL throughout the year ranging on average 2.0 and 2.2 was attributable to everyday tasks for subsistence and domestic works undertaking over 9–11 h (men spent 2.7 h on agricultural work and 4.7 h on animal herding, whereas women spent 7.3 h almost exclusively on animal herding). The seasonal increase in PAL was statistically significant, but it was smaller than those anticipated from published reports. A flexible division of labor played an important role in the equitable energetic increase in both men and women. Am. J. Hum. Biol., 2009. © 2009 Wiley-Liss, Inc

Iron and zinc content of selected foods in the diet of schoolchildren in Kumi district, east of Uganda: a cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Iron and zinc are essential micronutrients for humans and deficiency of the two elements is widespread in the world with the highest prevalence in less developed countries. There are few data on dietary intake of iron and zinc in Uganda, and no food composition table is available. There is hardly any widely published literature that clearly documents the quality of Ugandan children's diet. Thus information of both food intake and the concentration of these trace elements in local food ingredients are needed in order to assess daily intake.</p> <p>Methods</p> <p>The present study focused on the iron and zinc content in selected foods and intake of the micronutrients iron and zinc among schoolchildren in Kumi District, Uganda. Over a period of 4 weeks single 24-hour dietary recall interviews were carried out on a convenience sample of 178 schoolchildren (9-15 years old). Data from the dietary recalls was used when selecting foods for chemical analysis.</p> <p>Results</p> <p>Results from this study showed that the iron concentrations varied, and were high in some cereals and vegetables. The zinc concentrations in foods generally corresponded with results from other African countries (Mali and Kenya). Data from the 24-hour dietary recall showed that the daily Recommended Nutrient Intake (RNI) was met for iron but not for zinc.</p> <p>Conclusions</p> <p>The schoolchildren of Kumi district had a predominantly vegetable based diet. Foods of animal origin were consumed occasionally. The iron content in the selected foods was high and variable, and higher than in similar ingredients from Kenya and Mali, while the zinc concentrations were generally in accordance with reported values. The total daily zinc (mg) intake does not meet the daily RNI. The iron intake is adequate according to RNI, but due to iron contamination and reduced bioavailability, RNI may not be met in a vegetable based diet. More studies are needed to investigate possible sources of contamination.</p

Underreporting of dietary intake by body mass index in premenopausal women participating in the Healthy Women Study

Underreporting patterns by the level of obesity have not been fully assessed yet. The purpose of this study was to examine the differential underreporting patterns on cardiovascular risk factor, macronutrient, and food group intakes by the level of Body Mass Index (BMI). We analyzed cross-sectional baseline nutritional survey data from the population-based longitudinal study, the Healthy Women Study (HWS) cohort. Study subjects included 538 healthy premenopausal women participating in the HWS. Nutrient and food group intakes were assessed by the one-day 24-hour dietary recall and a semi-quantitative food frequency questionnaire, respectively. The ratio of reported energy intake (EI) to estimated basal metabolic rate (BMR) was used as a measure of relative energy reporting status and categorized into tertiles. Overweight group (BMI≥25kg/m2) had a higher ratio of EI to BMR (EI/BMR) than normal weight group (BMI<25kg/m2). Normal weight and overweight groups showed similar patterns in cardiovascular risk factors, nutrient intake, and food group intake by the EI/BMR. Fat and saturated fat intakes as a nutrient density were positively associated with the EI/BMR. Proportion of women who reported higher consumption (≥4 times/wk) of sugar/candy, cream and red meat groups was greater in higher tertiles of the EI/BMR in both BMI groups. Our findings suggest similar patterns of underreporting of cardiovascular risk factors, and macronutrient and food group intakes in both normal and overweight women

Impact of a school-based intervention to promote fruit intake: a cluster randomized controlled trial

OBJECTIVE: There is evidence that fruit consumption among school children is below the recommended levels. This study aims to examine the effects of a dietary education intervention program me, held by teachers previously trained in nutrition, on the consumption of fruit as a dessert at lunch and dinner, among children 6-12 years old. STUDY DESIGN: This is a randomized trial with the schools as the unit of randomisation. METHODS: A total of 464 children (239 female, 6-12years) from seven elementary schools participated in this cluster randomized controlled trial. Three schools were allocated to the intervention and four to the control group. For the intervention schools, we delivered professional development training to school teachers (12 sessions of 3 h each). The training provided information about nutrition, healthy eating, the importance of drinking water and healthy cooking activities. After each session, teachers were encouraged to develop classroom activities focused on the learned topics. Sociodemographic was assessed at baseline and anthropometric, dietary intake and physical activity assessments were performed at baseline and at the end of the intervention. Dietary intake was evaluated by a 24-h dietary recall and fruit consumption as a dessert was gathered at lunch and dinner. RESULTS: Intervened children reported a significant higher intake in the consumption of fruit compared to the controlled children at lunch (P = 0.001) and at dinner (P = 0.012), after adjusting for confounders. CONCLUSIONS: Our study provides further support for the success of intervention programmes aimed at improving the consumption of fruit as a dessert in children.CIEC – Research Centre on Child Studies, IE, UMinho (FCT R&D unit 317), Portuga

The effect of long term combined yoga practice on the basal metabolic rate of healthy adults

BACKGROUND: Different procedures practiced in yoga have stimulatory or inhibitory effects on the basal metabolic rate when studied acutely. In daily life however, these procedures are usually practiced in combination. The purpose of the present study was to investigate the net change in the basal metabolic rate (BMR) of individuals actively engaging in a combination of yoga practices (asana or yogic postures, meditation and pranayama or breathing exercises) for a minimum period of six months, at a residential yoga education and research center at Bangalore. METHODS: The measured BMR of individuals practicing yoga through a combination of practices was compared with that of control subjects who did not practice yoga but led similar lifestyles. RESULTS: The BMR of the yoga practitioners was significantly lower than that of the non-yoga group, and was lower by about 13 % when adjusted for body weight (P < 0.001). This difference persisted when the groups were stratified by gender; however, the difference in BMR adjusted for body weight was greater in women than men (about 8 and 18% respectively). In addition, the mean BMR of the yoga group was significantly lower than their predicted values, while the mean BMR of non-yoga group was comparable with their predicted values derived from 1985 WHO/FAO/UNU predictive equations. CONCLUSION: This study shows that there is a significantly reduced BMR, probably linked to reduced arousal, with the long term practice of yoga using a combination of stimulatory and inhibitory yogic practices