KANSAS CITY — The decade-long decline in domestic use of high-fructose corn syrup continued in 2017, even though production has steadied due to stable exports to Mexico that began ramping up as the result of the North American Free Trade Agreement in 2008. At the same time, the mix of HFCS (55% versus 42%) use has changed considerably over the years.

Domestic use of HFCS peaked at 9,248,000 tons, dry weight, in 2001-02 (fiscal 2002) and declined 25% to 6,950,000 tons in 2017, the lowest since 1993 when use still was increasing annually as it had since 1966, according to data from the U.S. Department of Agriculture. Production peaked at 9,477,000 tons in 2000 but dropped only 13% to 8,254,000 tons last year, the lowest since 1996. Exports, meanwhile, were 1,352,000 tons in fiscal 2017, down 21% from a peak of 1,722,000 tons in 2012 but have slightly increased since 2014. In comparison, exports were 96,000 tons in 1993 and 401,000 tons in 2000. Almost all U.S. HFCS exports go to Mexico.

“Consumption patterns for caloric sweeteners in the United States since 2008 have been characterized by more per capita consumption of refined sugar and less HFCS,” the U.S.D.A. said in its January Sugar and Sweeteners Outlook. The U.S.D.A. cited three reasons for the ongoing decline: higher corn prices and more of the corn crop being used to produce ethanol; increased sugar imports from Mexico under NAFTA; and increased food manufacturer formulation and labeling away from corn sweeteners “in response to perceived customer preferences.”

While deliveries of both 55% HFCS, used mostly in beverages, and 42% HFCS, used mostly in food items such as bakery and confectionery products, condiments and preserves, have declined in the past decade, they have been on different trajectories.

“Compared with the previous year, 2016-17 HFCS-42 deliveries fell 5.4%,” the U.S.D.A. said. “Deliveries of HFCS-55, which still constitute the majority of the domestic market, also declined, but at a lower rate of 0.6%. Both of these declines are consistent with the 10-year trend.”

At 4,663,000 tons, deliveries of 55% HFCS are down 16% from the peak in 2002, but domestic use has been stable if not rising slightly since 2012. Domestic disappearance of 42% HFCS, meanwhile, at 2,287,000 tons in 2017 was down 39% from its peak in 2006 and the lowest since 1993 (not considering the years use had been building since the 1960s).

Total per capita deliveries (versus actual consumption) of caloric sweeteners peaked at 151.6 lbs, dry weight, in 1999, which coincided with record high deliveries of corn sweeteners (HFCS, glucose and dextrose). Since that time (through calendar 2016), per capita deliveries of total corn sweeteners have declined 32.5%, refined sugar increased 5% (though down 32% from the peak in 1972) and total caloric sweeteners declined 15.5%.

The move away from HFCS began a few years ago in part due to a perceived but not scientifically proven difference in the effects of HFCS on weight and health versus sugar, which was seen as a more natural product, with some food manufacturers not wanting to have HFCS on their labels. Reports of switching away from HFCS have slowed, but not gone away, and have been influenced to some degree by fluctuations in sugar prices.

Production of HFCS in 2016-17 (fiscal 2017) was down 1.6% from a year earlier, with 42% HFCS down 4.4% and 55% HFCS down 0.5%, also following 10-year trends.

“Domestic markets have been declining more quickly than production, even with industrial reorganization among corn wet mill facilities in recent years to reduce capacity and increase utilization rates. Exports have become increasingly important, particularly for HFCS-55 sales. Foreign sales have grown over the past 10 years, with the great majority of exports destined for Mexico. Similar to increased imports of sugar from Mexico, HFCS producers also benefited from the implementation of NAFTA for sweetener markets, using the increased market access to grow trade with Mexico.”

The U.S.D.A. noted that HFCS exports to Mexico peaked in 2011-12 but remain significantly higher than before NAFTA and have been stable the past several years.