Ateldy Brasil Filho flag Denunciar. Figure 1. Land cover and land-use of Brazilian La Plata Basin in Since agricultural production in southern Brazil is highly mechanised and uses a high quantity of non- renewable inputs, such processes have resulted in high crop productivity, but have caused serious environmental damage such as soil compaction and erosion, water contamination, and vegetation devastation. The northern region of the Plata Basin includes part of the Cerrado ecosystem, which is characterised by low fertility soils that are also being gradually converted to annual crops like soybeans, wheat and maize VAMOS, Based on Filoso et al.
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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.
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. The relationship between agricultural production and population health is complex. Patterns of production lead to patterns of availability, price and distribution of food commodities.
These raw ingredients are then processed in increasingly complex ways by the food manufacturing system and the combined effects of food production and processing influence individual food consumption and thereby population health. Besides these primarily nutritional links, agricultural and food systems act as conduits of food-borne and zoonotic disease and agrochemical pollutants and compete with the water supply and sanitation needs of local communities.
In the context of international development, the interaction between health, agricultural productivity and income is particularly important since more than half of the world's poorest people live in farming communities, including many suffering from under-nutrition. Finally, the various interactions between agriculture, food and health increasingly play out on a global stage, with food produced in one region frequently consumed in another, mediated by trade liberalization and growing multinational food production and distribution industries.
To a large extent, global food production has kept up with the demands of a growing human population Dyson , but inequalities remain in regional and national distribution of the available food Sen Recent estimates suggest that globally the combined effect of inadequate macro protein—energy - and micro-nutrient including iron and iodine intakes underpin 35 per cent of all child deaths and are responsible for 11 per cent of the global disease burden Black et al.
There remains a clear challenge to define ways in which agricultural production could better contribute, through the food chain, to improved health for all people. To achieve this, we need to understand the interactions between agriculture, food systems and health and to have tools that allow us to predict the effects on health of agricultural change and innovation. In this paper, we explore our capacity to measure and predict agricultural impacts on health, focusing particularly on nutrition.
We begin by pulling together the diverse current literature on nutrition and health to identify what constitutes a healthy diet. We then examine how we currently measure food availability and consumption in different populations, looking particularly at our capacity to do this on a global scale. Finally, we explore whether, given the tools currently at our disposal, we are able accurately to assess the impact of changes in agriculture and food systems on population health and the potential for health to act as a driver to stimulate these changes.
It has long been recognized that a balance of nutrients forms the basis of a healthy diet, and ongoing research continues to further our understanding in this area. Carbohydrates are the predominant source of energy in the diet, playing a key role in metabolism and the maintenance of homeostasis. The type and balance of carbohydrates in the diet are of great importance to health. While, in contrast, diets rich in complex carbohydrates such as whole-grain cereals, vegetables and nuts contribute to lowering the risk of type 2 diabetes de Munter et al.
Fats are a second major dietary energy source and are essential for growth and development in early life. It is increasingly recognized that different structural categories of fats have contrasting impacts on health Lecerf For example, there is strong evidence that the consumption of trans -fatty acids TFAs increases the risk of cardiovascular disease, with potential adverse effects also on insulin resistance and adiposity Teegala et al. In contrast, the omega-3 long-chain polyunsaturated fatty acids omega-3 LCPs , most commonly found in fish, have been shown to have beneficial effects for cardiovascular health Scientific Advisory Committee on Nutrition ; Lecerf There is also no evidence that consuming supplemental omega-3 LCPs in later life helps slow cognitive decline Dangour et al.
Beyond the primarily metabolic demand, attention is now focusing on the role of protein intakes in promoting lifelong health and there is emerging evidence that protein quality may have consequences for optimal muscle and bone growth Millward et al.
The most recent expert consultation on protein requirements stated that an intake of 0. In reality, diets are not categorized based purely on their macronutrients content, but instead are composed of different foods providing specific combinations of macro- and micro-nutrients. One of the most diverse food groups is fruits and vegetables, which play an important role in promoting health.
No single known component nutrient explains the observed beneficial health effects of consuming a high vegetable and fruit diet and their impact is likely due to a combination of being low in energy density, high in fibre and a source of vitamins and minerals as well as to lesser-understood bioactive components such as polyphenols.
In some countries and cultures, meat and dairy products are an important part of the diet, representing good sources of protein and a range of minerals such as iron, zinc and calcium and micro-nutrients such as vitamin B In contexts where dietary intakes are sub-optimal, animal source food products can be an essential source of these important nutrients.
However, some meat and dairy products are also a major contributor of saturated fat in the human diet, and high intake of saturated fat is consistently associated with increased risk of heart disease, largely because of the effect on serum cholesterol concentrations Hu et al.
There are evident complexities in defining the relationships between population nutritional intake and health. It is therefore a challenge to provide comprehensive dietary guidelines for population intakes based on the global diversity of primary foodstuffs.
Dietary guidelines have been part of public health nutrition policies since the early twentieth century. These guidelines, often produced by expert bodies, initially focused on the prevention of specific nutrient inadequacies, but more recently, their focus has changed to the prevention of food and nutrition-related chronic diseases.
However, expert reports rarely synthesize evidence into dietary guidelines that encompass nutritional inadequacy, infectious and chronic disease.
The review identified 94 expert reports of which only three two from India and one from South Africa arose from expert panels in low-income countries. Generally, reports recommended diets high in cereals, vegetables, fruits and pulses and low in red and processed meats. Summary of expert panel dietary recommendations for the prevention of nutritional deficiencies, infectious and chronic diseases.
Recommendations have only been included if they were made in three or more reports. Currently, the WHO recommends, among others, vitamin A supplementation to children in at-risk areas de Benoist et al. Evidence from around the world suggests that economic development results in major transitions in population-level dietary, and corresponding disease, patterns.
The dietary changes are themselves driven by a variety of culturally specific factors including the increased production, availability and marketing of processed foods and the complex effects of urbanization Popkin The future prospects look bleak as societal change in low- and middle-income countries is accelerating the nutrition transition Popkin Furthermore, as rural to urban migration continues, there will be increasing dependency on complex food chains, which implies that the direction of these dietary transitions is and will be one way.
The consequences for population prevalence of nutrition-related chronic disease are all too evident; the WHO Global Burden of Disease project lists coronary heart disease and stroke within the top 10 leading causes of death worldwide with diabetes mellitus also a leading cause of death in high- and middle- and increasingly in low-income countries WHO Changing patterns of agricultural production, food availability and processing will have profound impacts on individual food consumption and, as a result, on population health.
A thorough understanding of these impacts requires a dependable means of measuring food consumption around the world. In the following sections, we compare the methods currently used to assess food consumption, particularly the estimation of food consumption from patterns of food production and availability through food balance sheets FBS , from studies of food purchases as part of household budget surveys HBS and from individual dietary surveys.
These methods are also critiqued elsewhere in this supplement as part of an analysis of food consumption trends Kearney The United Nations Food and Agriculture Organization FAO compiles national data on food production and on per capita food availability for most countries in the world.
Production data are presented for the top 20 most important food and agricultural commodities produced in a given country in terms of their value and size.
Food availability data are presented in FBS and provide figures on the estimated availability of over foodstuffs in grams per capita per day. The food available for consumption is then calculated after estimating the amount used for industrial or agricultural purposes for example, as seed or for animal consumption or bio-fuels , wastage in the production system and change in national stock levels.
It is important to emphasize that measures of food availability are not measures of food consumption, but in the absence of other data, food availability is widely used as a proxy for food consumption. The calculation of food availability is subject to a range of potential errors, from the initial calculation of production and trade to the determination from this of what food is available for consumption.
This lack of good quality data is particularly acute for certain developing countries where there may be no official statistics; FAO currently fills this gap by providing its own modelled or imputed estimates of food production, which are used for over 70 per cent of African countries and for over 50 per cent of countries from Asia and the Pacific CC-IEE Figures on animal populations and production parameters provide further illustration of errors inherent in office-based estimates.
A striking example from this region is the difference in estimates in Brazilian cattle populations, with the official number being million compared with estimates of million FNP Consultoria e Comercio As agricultural production numbers form the basis of FBS estimates of food availability, errors of this magnitude will have important consequences for the accuracy of the resulting food availability data, and any estimates of consumption calculated from these.
At the level of estimating per capita food availability, errors in FBS estimates can result from incomplete or out-of-date country-specific population estimates which are usually based on the resident population and do not take into account tourists, illegal immigrants or refugees. This issue may be particularly pronounced for many sub-Saharan African countries where published population census data are often out of date and are likely to suffer from undercounting and misreporting due to issues of accessibility, risk and the conceptual problems of encompassing highly mobile populations and complex patterns of household formation Sender et al.
FBS data provide incomplete information on the level of home production of foods or on the level of processing different food commodities undergo prior to their availability for consumption. In many low-income countries, foods produced at home which do not reach the market remain largely unprocessed and are predominant in the household diet.
In contrast, as countries undergo the nutrition transition, foods are often highly processed, and FBS data based on the production and trade of agricultural commodities are unable to provide information on the composition of the processed foods actually available for consumption.
Finally, a key source of error in using FBS food availability statistics as a proxy for food consumption is that FBS data do not allow for food waste at the retail and household level. This level of food wastage can be particularly high in urban areas of developed countries, but will vary greatly both between and within countries. In the UK, it has been estimated that one-third of all food purchases i. HBS generally conducted by national statistical offices are available from many countries in the world including an increasing number of low-income countries Smith et al.
These surveys generally aim to acquire nationally representative information on household expenditure for a range of commodities, including food, primarily to construct cost-of-living indices. Where HBS include information on the quantities of different types of foods purchased, as well as consumption from own production, this information equates to the food available at the household level and is therefore frequently used as a proxy estimate of consumption in a manner similar to FBS food availability data.
In HBS, dietary data are collected as part of the larger household level survey, which is a strength as they can be related to the socio-economic status of the household and, provided the sample is representative, regional variations can also be investigated. In reality, however, samples are not always representative due to issues such as a lack of accurate sampling frame, poor response rates and a tendency to over-sample urban compared with rural areas and poorer compared with wealthier households.
Other important limitations of using HBS data to assess the composition of the household diet include a lack of information on food consumed outside the home, on waste within the household or on food used for other reasons such as pet food or fed to guests. Measuring the consumption of home-produced food may also prove difficult. In addition, the methodologies used may not be directly comparable between countries Naska et al.
A further important limitation when using the data as a proxy for individual dietary intake is the lack of information on the distribution of food within the household.
A final consideration is that seasonal trends in food consumption are not captured by these surveys unless they are conducted year-round, which has its own consequences in terms of implementation costs. However, a recent comparison of data from 18 European countries reported a general tendency for HBS-derived values to be lower than those from FBS for the major food groups Naska et al. Despite the lower values in HBS, estimates from the two methods of the availability of most food groups, with the exception of meat products, correlated well Naska et al.
HBS and FBS are thus complementary methods of assessing food availability and have an important role to play in informing public policy. However, because of their inherent limitations, they are not able to provide accurate data on food consumption at the individual level Serra-Majem et al.
Direct estimates of individual food consumption for a population are generally derived from surveys conducted on nationally representative samples. When conducted properly, individual dietary intake data from population surveys can often be sub-divided by age and sex categories and used to investigate regional and socio-economic variations.
There is a surprising paucity of nationally representative surveys even from high-income country settings. Indeed, in order to estimate the consumption of fruit and vegetables by individuals worldwide, the Global Burden of Disease project was only able to identify nationally representative dietary intake survey data from 26 countries and had to rely entirely on FBS food availability data for African countries Lock et al.
This lack of dietary intake surveys probably arises from the complexities and expense involved in conducting regular high-quality rounds of data collection and analysis, insufficient information on the energy and nutrient composition of local foods and low participant literacy levels in some countries Ferro-Luzzi Collecting individual dietary intake data involves methods such as weighed records, 24 h recalls and food frequency questionnaires, none of which is error free.
Twenty-four-hour recall methods are commonly used, although must be repeated on several days to more accurately capture habitual dietary intake Gibson Food frequency questionnaires require fewer resources, but there exists an ongoing debate around the validity of dietary intake data reported via this method Bingham et al.
Difficulties in comparison and interpretation of individual dietary intake data collected in different countries also arise from the use of diverse study designs, sampling frames, seasonal variation in dietary intake and methods of data collection. In order to examine the challenges posed in the comparison of individual dietary intake surveys with the more globally available FBS data on food availability, we present an analysis involving national surveys of individual dietary intake and FBS food availability data from two countries: the UK and Mexico.
We selected these two national surveys to compare countries at different stages of development from different regions of the world.
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Carcass and meat characteristics from young Devon steers finished in different feeding systems. The carcass and meat characteristics were assessed of Devon steers finished in feedlot CONF , temperate pasture ryegrass pasture - Lolium multiflorum Lam -PTEM , or tropical pasture association of millet pasture - Pennisetum americanum L. At the beginning of finishing the average weight of the steers was kg and the age was 15 months. The animals in feedlot were fed feeds with roughage:concentrate and slaughtered with similar weights of Finishing on tropical pasture increased the slaughter age from 17 to 19 months, due to lower average daily weight gain compared to the feedlot and the temperate pasture. The feeding system did not influence the hot and cold carcass weight, nor the hot and cold carcass dressing percentage, even though the carcasses of the animals finished on tropical pasture showed greater chilling loss compared to the temperate pastures. Subcutaneous fat thickness and carcass conformation were higher for the animals finished on temperate pastures than those finished on temperate pasture, while the animals finished in feedlot maintained an intermediary position.
Progress in the Brazilian cattle industry: an analysis of the Agricultural Censuses database