Consumption of added sugar, generally, and HFCS, specifically, has been hypothesized as a contributing factor to the rising rates of obesity observed over the past few decades. Mechanistically, this hypothesis is based on differences in the rates of digestion and absorption between fructose and glucose (36
) and the observation that increased consumption of sugar-sweetened beverages is associated with weight gain over time (15
). These topics are beyond the scope of this paper, but are addressed elsewhere in this supplement. The purpose of this paper was to examine the trends and patterns of HFCS and added sugar consumption in both beverages and foods.
We report that daily per capita intake of calories from HFCS and added sugar has followed a general upward trend since the mid-1960s. Despite a drop in sugar consumption between 1965 and 1977, added sugar accounted for 17% of total daily energy intake and 32% of total carbohydrate intake among Americans 2 years and older. These values represented an increase of 31% (from the lowest value in 1977) and 23% (from the lowest value in 1991), respectively. The trend in HFCS consumption has been steadier; between 1991 and 2000 there was a 120% increase in calories from HFCS, and since 2000, calories from HFCS have remained relatively stable. These values represented 8.5% of total energy and 15.9% of carbohydrates in 2004—an increase of 67% and 57%, respectively, from estimated intake in 1989.
Our results are consistent with those reported elsewhere by our research team. In a study examining worldwide shifts in added sugar availability and consumption, Popkin and Nielsen reported an increase from 235 calories from added sugar in 1977 to 318 calories from added sugar in 1996 (43
). Similar trends in the number of calories from added sweetener by food group were also reported. Using the same Glinsmann method as reported here, Bray et al (10
) examined HFCS consumption between 1977 and 1998 for a select set of food groups, namely soft drinks, fruit drinks and desserts. As reported in our paper, Bray et al. found a general increasing trend in added sugar and HFCS consumption from the three food sources they examined. The present study expanded on these results by estimating HFCS contribution to caloric intake from numerous additional food sources over a longer time period.
The patterns we have observed are also consistent with recent literature on trends in the location and types of foods being consumed. Between 1977 and 1996, salty snacks, pizza, and sugar-sweetened beverages showed the largest increases in consumption among all age groups, but the largest changes were observed in the younger (2–18 and 19–39) ages (44
). Location of energy consumption is also shifting, with energy from fast food places and restaurants replacing energy consumed at home (44
). Furthermore, people reported that foods that can be easily obtained from these food sources (ie, hamburgers and cheeseburgers) were almost exclusively consumed away from home, suggesting that the types of foods prepared at home have shifted (44
Our study shows that calories from added sugar and HFCS from similar types of foods (i.e. hamburgers, snacks, sodas) has continued to rise, or at least reached a plateau, since 1996. Many of these foods, particularly sugar- sweetened beverages, account for a greater percent of total energy intake in 2004 than they did even 20 or 30 years ago. Furthermore, since foods & beverages are typically not consumed independently of one another, contribution of any food or beverage to an individuals’ total daily energy intake is potentially much larger.
This paper has several limitations. First, because of the lack of available data, the amount of HFCS in foods had to be estimated. Since little work has been done to estimate HFCS intake, we employed two different estimation methods—one based on availability (Glinsmann Method) and one on measured fructose (NCC Method) in foods. For some key food groups, these methods resulted in significantly different estimates (ie, the desserts food group). These differences are likely the result of differences between the two estimation techniques, each of which required acceptance of certain assumptions.
With respect to the NCC (measured fructose) Method, a direct measure of fructose was not available for all foods reportedly consumed in the USDA database; linkage codes between NCC and USDA data were available for only about 1,000 foods. For foods where no direct link was possible, we applied an average fructose value (based on the food group to which that particular food was assigned), which likely resulted in a misestimation of fructose, and HFCS, for many foods. However, it is impossible to predict the direction of this misestimation for any individual food/beverage item. To reduce misestimation, we grouped foods according to their added sugar content. However, within some food groups, a large range of added sugar and fructose would result in a dilution of average values within a food group. Additionally, for some foods from NHANES 2003–2004, direct measures of added sugar were not available. For these foods, we applied sugar values from the closest matching 8-digit USDA food code from the previous time point (NHANES 2001–2002). When there were no comparable foods in previous USDA files (ie, Propel Fitness water), we used nutritional information provided by the manufacturers and calculated added sugar values from this information. Our estimates of HFCS consumption using the Glinsmann Method are based on availability of data from the mid-1980s; they are likely to under-represent HFCS availability within these sectors today.
Second, our data are limited by differential collection methods between exams and differential time spans over which data were collected. The first three exam periods (1965, 1977, 1989–1991) cover a span of more than 15 years, while the last three periods (1999–2000, 20001-2002 and 2003–2004) cover just five years, which may not be long enough to observe sensitive changes in consumption patterns. To create more comparable time spans between studies, we combined the NHANES data into a single survey and reexamined trends. Although the trends in added sugar were slightly clearer using the combined surveys, HFCS could not be estimated (recall that HFCS was not widely used in food products until the late 1990s). Thus we elected to keep each NHANES survey separate. Some of the differences in observed consumption may also be due to changes in data collection methods. In 2000, the automated multiple pass method was used for dietary collection. This tool is designed with internal prompts to help decrease the incidence of underreporting, thereby increasing the accuracy of data collection. While this may result in an increase in reporting frequency of foods and beverages, it is unlikely to account for the large changes reported here.
In general, availability and consumption of HFCS and added sugar has increased over the past three decades. We report that the types of foods and beverages contributing to daily energy intake from HFCS have shifted over the past several decades: desserts accounted for roughly 4% of total energy intake in 1965. This number dropped to 3% by 2004, while soda accounted for 6.8% of total energy intake in the same year. Although sweetened beverages, such as soda and fruit drinks, currently account for the largest proportion of energy from HFCS, we report that other beverages (sports drinks) and foods (desserts, breads, and ready-to-eat cereals) are also contributing considerable amounts of per capita energy intake. These are foods that are often consumed as snacks rather than meals (44
), so ultimately, it seems that HFCS (and other added sugar) is not what’s for
dinner, it’s what’s in addition