Consumption Levels of Dietary Fats and Oils in 1990 and 2010
Consumption Levels of Dietary Fats and Oils in 1990 and 2010
This systematic investigation of individual-level dietary assessments across the world provides, for the first time, quantitative estimates of the global consumption of major dietary fats and oils by region, country, age, and sex, as well as the uncertainty in these measurements. Since suboptimal diet is the single leading cause of death and disability in the world today, these findings are highly relevant and of crucial interest to the global scientific community, health professionals, policy makers, and the public. The results demonstrate both similarities and substantial diversity in consumption of fats and oils across regions and nations. These findings facilitate quantitative assessment of disease burdens attributable to these dietary factors—such as by using state-transition Markov models, food impact models, and comparative risk assessment—and inform public health and policy priorities for global, regional, and country-specific interventions. We also assessed dietary changes over the past 20 years, although some change estimates should be interpreted with caution due to more limited available data over time.
At a global level, mean consumption of saturated fat (9.4%E; guideline<10%E) and dietary cholesterol (228 mg/day; guideline<300 mg/day) were in line with current recommendations or optimal intakes. Reductions of saturated fat and dietary cholesterol have been longstanding public health priorities. In 2010, national saturated fat and cholesterol intakes met recommended intakes in countries representing about 60% and 88% of the global adult population, respectively, suggesting that this public health focus has been relatively successful. Lowest intakes were identified in South and East Asia, South America, and certain Caribbean nations. Such low intakes would be beneficial for coronary heart disease, especially when accompanied by reciprocal increases in polyunsaturated fat intake, although very low saturated fat intake may increase risk of other outcomes, such as hemorrhagic stroke. Based on crude national availability and production estimates, saturated fat consumption in some countries decreased after the mid-20th century. Our results demonstrate relatively stable global and regional intakes of saturated fat and cholesterol in more recent years since 1990, except for further declines in certain Eastern European nations. These relatively stable intakes since 1990 may be attributable in part to national programmes in some countries having most of their effect on saturated fat and dietary cholesterol before 1990. For example, Finland constitutes one of the best documented examples of a community intervention that had most of its effect prior to 1990, with further (though smaller) declines seen after that. In addition, effectiveness of recent population-level approaches to reduce saturated fat in some countries could have been offset by increasing Westernisation of diets and cultural and social prioritisation of red meats.
Intakes of polyunsaturated fats, which have historically received less public health and policy attention than saturated fat or dietary cholesterol, were far below optimal worldwide. Intakes were lowest in several Pacific island nations with very high intakes of palm oil, creating adverse ratios of polyunsaturated to saturated fats in these nations. Low intakes were also identified in many Southeast Asian and Sub-Saharan African countries, suggesting infrequent use of healthful vegetable oils for cooking or preparing foods. In some regions such as Eastern Europe, significant increases in polyunsaturated fat and reciprocal declines in saturated fat intake were identified between 1990 and 2010, demonstrating feasibility of such broad population substitutions to reduce coronary heart disease risk. Ecological analyses based on commodity disappearance data are consistent with these findings. Yet, despite promising overall increases in polyunsaturated fat intakes over the past two decades, the great majority of nations consume lower than optimal levels, highlighting the need to increase public health awareness and focus on healthy vegetable oils. The absence of strong intercorrelation between polyunsaturated and saturated fat consumption (nationally, -0.22) suggests that these dietary risk factors for coronary heart disease are consumed relatively independently and should be targeted separately to reduce risk, particularly as benefits of replacing either saturated fat or carbohydrates with polyunsaturated fat may be relatively similar.
Consistent with local cultures, highest seafood omega 3 consumption was identified in Pacific island nations, the Mediterranean basin, Iceland, South Korea, and Japan (although in the last two countries, large amounts are from salted foods, which might increase stroke and gastric cancer). Yet, 142 countries representing nearly 80% of the world’s adult population had mean seafood omega 3 intakes below 250 mg/day. Extremely low levels (often <100 mg/day) were identified in Sub-Saharan Africa, South America (except Chile), and Asian mainland nations. These findings highlight the dearth of seafood omega 3 fats in much of the world and the need for concerted public health and policy initiatives, including focus on sustainable aquaculture and fishing practices, to increase both supply and consumption. Whereas global seafood omega 3 consumption increased by about 25 mg/day between 1990 and 2010, we found that much of this was due to further increases in countries already having relatively high consumption.
In 2010, mean global consumption of plant omega 3 was 1371 mg/day. While this is consistent with current broad guidance for adequate intakes (≥1100 mg/day) and for preventing clinical deficiency, optimal intakes of plant omega 3 for reducing chronic diseases are not well established. In addition, we identified remarkable heterogeneity in intakes, with roughly 10-fold differences across regions and 61 countries having mean intakes <500 mg/day. Based on ecological evidence, increasing plant omega 3 consumption can reduce population coronary heart disease risk within a few years. However, definitive cardiometabolic benefits and optimal intake levels are not yet conclusively established. The extent to which the identified regional and national increases in consumption since 1990 relate to contemporaneous trends in mortality from cardiovascular disease or other diseases requires further investigation.
While several high income countries have recently established national or subnational policy efforts to reduce trans fat consumption, little prior data was available on global intakes of trans fat. Our findings suggest substantial heterogeneity across the world. Relatively few countries had mean intakes >2%E; conversely, most countries have not achieved optimal intakes of <0.5%E. Highest consumption was evident in North America, North Africa/Middle East, and South Asia, especially Pakistan. While commercial foods are a major source of trans fat in high income countries, intakes in low and middle income counties are principally derived from home and street vendor use of inexpensive partially hydrogenated cooking fats. In addition, trans fat intake can be highly skewed in certain subgroups, so that national means obscure population subsets with much higher intakes. For example, whereas mean trans fat intake in India was 1.1%E, consistent with proprietary industry data (personal communication, Mark Stavro, Bunge LLC), both the industry data as well as observations of Indian authorities suggest substantial heterogeneity in trans fat intakes across different Indian states, with several having much higher intakes. Our findings also highlight the relatively limited data availability on trans fat consumption in most nations compared with other major dietary factors. These results demonstrate the need for increased global and nation surveillance as well as consumption reduction strategies.
Interestingly, intakes of most dietary fats and oils were similar by sex, both regionally and within countries. Differences by age were evident for trans fat, with highest consumption at younger ages, perhaps because of greater consumption of processed foods. Age differences were also seen for dietary cholesterol and seafood omega 3 fats, with higher intakes at older ages. For seafood omega 3 fats, the identified age pattern could relate to a birth cohort effect—that is, maintenance of traditional diets or to adoption of healthier diets at older ages because of concerns about disease risk with aging. For cholesterol, the identified age pattern highlights the need for further investigation.
Our investigation has several strengths. Systematic searches and extensive direct contacts allowed us to identify, assess, and compile, for the first time, global individual-level dietary data, largely from national studies, on major dietary fats and oils worldwide, including by age, sex, and time. Identified surveys were evaluated for eligibility, measurement comparability, and representativeness; and consistency across surveys was maximised by standardised data extraction and analyses, reinforcing validity and generalisability. Metrics and measurement units were standardised across surveys and were based on the evidence for effects on disease risk. Intakes were adjusted for total energy, reducing measurement error; and sensitivity analyses without energy adjustment were similar. We developed a hierarchical imputation model to address missing data, differences in representativeness and comparability, and related effects on statistical uncertainty. We collected data and imputed intakes using multiple surveys and covariates over time, providing inference on dietary trends.
Potential limitations should be considered. Despite comprehensive approaches to data identification and retrieval, primary data were limited for certain dietary factors, countries, and time periods: for example, more data were available for 2010 than 1990, and relatively little data were available in most Sub-Saharan African nations or for trans fats and plant omega 3 fats. Yet, our modelling methods included surveys over time within and across regions and countries, incorporated serial food balance data as covariates, and quantified resulting statistical uncertainty.
Our findings highlight the need for expanded systematic surveillance of key dietary habits globally and especially in regions with sparse data, including consideration of instrument representativeness, validity, and comparability. Our results also underscore the need for improved food composition databases in many countries, especially for trans fat and plant omega 3 fats. To maximise practicality and data retrieval from diverse global contacts, we focused on dietary fats and oils with probable or convincing evidence of aetiological effects on chronic diseases (for example, we did not gather data on monounsaturated fats, which have differing relations with risk when derived from animal versus plant sources). Our methods incorporated data across multiple years to derive the best estimates of intakes in 1990 and 2010, which increased validity of estimates in these years but reduced the ability to detect acute changes in national intakes, such as after major policy initiatives. Because of our focus on chronic diseases, we did not collect data in children. We plan to update and expand this work in the future, to identify and incorporate new data, add new dietary factors and age groups, and refine our estimation methods, including for trends over time.
Numerous epidemiological studies and several clinical trials have documented the health benefits and harms of specific dietary fats and oils. Yet, far less progress has been achieved in understanding the patterns of global consumption as well as heterogeneity by country, age, sex, and time. Our investigation, founded on individual-level, nationally representative surveys, provides a systematic and comprehensive quantitative assessment of the global consumption of key dietary fats and oils. These findings permit detailed investigation of the impact of dietary habits on disease burdens across countries, of the correlates and drivers of current dietary intakes and nutrition transitions over time, and of the impact of national policies and interventions that—intentionally or inadvertently—alter population dietary intakes. These results inform national and global efforts to alter diet, reduce disease, and improve population health. Our findings also highlight specific data gaps and provide a framework for future dietary surveillance using validated, standardised, nationally representative surveys supported by appropriate food composition data. Understanding the global patterns and impact of suboptimal dietary habits is essential to inform, implement, and evaluate specific interventions and policies to reduce disease burdens and disparities around the world.
Discussion
Relevance of Findings for Public Health
This systematic investigation of individual-level dietary assessments across the world provides, for the first time, quantitative estimates of the global consumption of major dietary fats and oils by region, country, age, and sex, as well as the uncertainty in these measurements. Since suboptimal diet is the single leading cause of death and disability in the world today, these findings are highly relevant and of crucial interest to the global scientific community, health professionals, policy makers, and the public. The results demonstrate both similarities and substantial diversity in consumption of fats and oils across regions and nations. These findings facilitate quantitative assessment of disease burdens attributable to these dietary factors—such as by using state-transition Markov models, food impact models, and comparative risk assessment—and inform public health and policy priorities for global, regional, and country-specific interventions. We also assessed dietary changes over the past 20 years, although some change estimates should be interpreted with caution due to more limited available data over time.
Principal Findings and Interpretation
At a global level, mean consumption of saturated fat (9.4%E; guideline<10%E) and dietary cholesterol (228 mg/day; guideline<300 mg/day) were in line with current recommendations or optimal intakes. Reductions of saturated fat and dietary cholesterol have been longstanding public health priorities. In 2010, national saturated fat and cholesterol intakes met recommended intakes in countries representing about 60% and 88% of the global adult population, respectively, suggesting that this public health focus has been relatively successful. Lowest intakes were identified in South and East Asia, South America, and certain Caribbean nations. Such low intakes would be beneficial for coronary heart disease, especially when accompanied by reciprocal increases in polyunsaturated fat intake, although very low saturated fat intake may increase risk of other outcomes, such as hemorrhagic stroke. Based on crude national availability and production estimates, saturated fat consumption in some countries decreased after the mid-20th century. Our results demonstrate relatively stable global and regional intakes of saturated fat and cholesterol in more recent years since 1990, except for further declines in certain Eastern European nations. These relatively stable intakes since 1990 may be attributable in part to national programmes in some countries having most of their effect on saturated fat and dietary cholesterol before 1990. For example, Finland constitutes one of the best documented examples of a community intervention that had most of its effect prior to 1990, with further (though smaller) declines seen after that. In addition, effectiveness of recent population-level approaches to reduce saturated fat in some countries could have been offset by increasing Westernisation of diets and cultural and social prioritisation of red meats.
Intakes of polyunsaturated fats, which have historically received less public health and policy attention than saturated fat or dietary cholesterol, were far below optimal worldwide. Intakes were lowest in several Pacific island nations with very high intakes of palm oil, creating adverse ratios of polyunsaturated to saturated fats in these nations. Low intakes were also identified in many Southeast Asian and Sub-Saharan African countries, suggesting infrequent use of healthful vegetable oils for cooking or preparing foods. In some regions such as Eastern Europe, significant increases in polyunsaturated fat and reciprocal declines in saturated fat intake were identified between 1990 and 2010, demonstrating feasibility of such broad population substitutions to reduce coronary heart disease risk. Ecological analyses based on commodity disappearance data are consistent with these findings. Yet, despite promising overall increases in polyunsaturated fat intakes over the past two decades, the great majority of nations consume lower than optimal levels, highlighting the need to increase public health awareness and focus on healthy vegetable oils. The absence of strong intercorrelation between polyunsaturated and saturated fat consumption (nationally, -0.22) suggests that these dietary risk factors for coronary heart disease are consumed relatively independently and should be targeted separately to reduce risk, particularly as benefits of replacing either saturated fat or carbohydrates with polyunsaturated fat may be relatively similar.
Consistent with local cultures, highest seafood omega 3 consumption was identified in Pacific island nations, the Mediterranean basin, Iceland, South Korea, and Japan (although in the last two countries, large amounts are from salted foods, which might increase stroke and gastric cancer). Yet, 142 countries representing nearly 80% of the world’s adult population had mean seafood omega 3 intakes below 250 mg/day. Extremely low levels (often <100 mg/day) were identified in Sub-Saharan Africa, South America (except Chile), and Asian mainland nations. These findings highlight the dearth of seafood omega 3 fats in much of the world and the need for concerted public health and policy initiatives, including focus on sustainable aquaculture and fishing practices, to increase both supply and consumption. Whereas global seafood omega 3 consumption increased by about 25 mg/day between 1990 and 2010, we found that much of this was due to further increases in countries already having relatively high consumption.
In 2010, mean global consumption of plant omega 3 was 1371 mg/day. While this is consistent with current broad guidance for adequate intakes (≥1100 mg/day) and for preventing clinical deficiency, optimal intakes of plant omega 3 for reducing chronic diseases are not well established. In addition, we identified remarkable heterogeneity in intakes, with roughly 10-fold differences across regions and 61 countries having mean intakes <500 mg/day. Based on ecological evidence, increasing plant omega 3 consumption can reduce population coronary heart disease risk within a few years. However, definitive cardiometabolic benefits and optimal intake levels are not yet conclusively established. The extent to which the identified regional and national increases in consumption since 1990 relate to contemporaneous trends in mortality from cardiovascular disease or other diseases requires further investigation.
While several high income countries have recently established national or subnational policy efforts to reduce trans fat consumption, little prior data was available on global intakes of trans fat. Our findings suggest substantial heterogeneity across the world. Relatively few countries had mean intakes >2%E; conversely, most countries have not achieved optimal intakes of <0.5%E. Highest consumption was evident in North America, North Africa/Middle East, and South Asia, especially Pakistan. While commercial foods are a major source of trans fat in high income countries, intakes in low and middle income counties are principally derived from home and street vendor use of inexpensive partially hydrogenated cooking fats. In addition, trans fat intake can be highly skewed in certain subgroups, so that national means obscure population subsets with much higher intakes. For example, whereas mean trans fat intake in India was 1.1%E, consistent with proprietary industry data (personal communication, Mark Stavro, Bunge LLC), both the industry data as well as observations of Indian authorities suggest substantial heterogeneity in trans fat intakes across different Indian states, with several having much higher intakes. Our findings also highlight the relatively limited data availability on trans fat consumption in most nations compared with other major dietary factors. These results demonstrate the need for increased global and nation surveillance as well as consumption reduction strategies.
Interestingly, intakes of most dietary fats and oils were similar by sex, both regionally and within countries. Differences by age were evident for trans fat, with highest consumption at younger ages, perhaps because of greater consumption of processed foods. Age differences were also seen for dietary cholesterol and seafood omega 3 fats, with higher intakes at older ages. For seafood omega 3 fats, the identified age pattern could relate to a birth cohort effect—that is, maintenance of traditional diets or to adoption of healthier diets at older ages because of concerns about disease risk with aging. For cholesterol, the identified age pattern highlights the need for further investigation.
Strengths and Limitations of Study
Our investigation has several strengths. Systematic searches and extensive direct contacts allowed us to identify, assess, and compile, for the first time, global individual-level dietary data, largely from national studies, on major dietary fats and oils worldwide, including by age, sex, and time. Identified surveys were evaluated for eligibility, measurement comparability, and representativeness; and consistency across surveys was maximised by standardised data extraction and analyses, reinforcing validity and generalisability. Metrics and measurement units were standardised across surveys and were based on the evidence for effects on disease risk. Intakes were adjusted for total energy, reducing measurement error; and sensitivity analyses without energy adjustment were similar. We developed a hierarchical imputation model to address missing data, differences in representativeness and comparability, and related effects on statistical uncertainty. We collected data and imputed intakes using multiple surveys and covariates over time, providing inference on dietary trends.
Potential limitations should be considered. Despite comprehensive approaches to data identification and retrieval, primary data were limited for certain dietary factors, countries, and time periods: for example, more data were available for 2010 than 1990, and relatively little data were available in most Sub-Saharan African nations or for trans fats and plant omega 3 fats. Yet, our modelling methods included surveys over time within and across regions and countries, incorporated serial food balance data as covariates, and quantified resulting statistical uncertainty.
Our findings highlight the need for expanded systematic surveillance of key dietary habits globally and especially in regions with sparse data, including consideration of instrument representativeness, validity, and comparability. Our results also underscore the need for improved food composition databases in many countries, especially for trans fat and plant omega 3 fats. To maximise practicality and data retrieval from diverse global contacts, we focused on dietary fats and oils with probable or convincing evidence of aetiological effects on chronic diseases (for example, we did not gather data on monounsaturated fats, which have differing relations with risk when derived from animal versus plant sources). Our methods incorporated data across multiple years to derive the best estimates of intakes in 1990 and 2010, which increased validity of estimates in these years but reduced the ability to detect acute changes in national intakes, such as after major policy initiatives. Because of our focus on chronic diseases, we did not collect data in children. We plan to update and expand this work in the future, to identify and incorporate new data, add new dietary factors and age groups, and refine our estimation methods, including for trends over time.
Conclusions and Policy Implications
Numerous epidemiological studies and several clinical trials have documented the health benefits and harms of specific dietary fats and oils. Yet, far less progress has been achieved in understanding the patterns of global consumption as well as heterogeneity by country, age, sex, and time. Our investigation, founded on individual-level, nationally representative surveys, provides a systematic and comprehensive quantitative assessment of the global consumption of key dietary fats and oils. These findings permit detailed investigation of the impact of dietary habits on disease burdens across countries, of the correlates and drivers of current dietary intakes and nutrition transitions over time, and of the impact of national policies and interventions that—intentionally or inadvertently—alter population dietary intakes. These results inform national and global efforts to alter diet, reduce disease, and improve population health. Our findings also highlight specific data gaps and provide a framework for future dietary surveillance using validated, standardised, nationally representative surveys supported by appropriate food composition data. Understanding the global patterns and impact of suboptimal dietary habits is essential to inform, implement, and evaluate specific interventions and policies to reduce disease burdens and disparities around the world.
