Study: Rising U.S. Temperatures Linked to Increased Consumption of Sugary Drinks and Desserts

A new international study published in Nature Climate Change found that higher temperatures in the United States are associated with increased consumption of sugary beverages and, to a lesser extent, frozen desserts — an effect that researchers say adds up to more than 100 million pounds (358 million kilograms) of extra added sugar consumed nationally each year compared with 15 years earlier.

Researchers report that when daily temperatures range between 54 and 86 degrees Fahrenheit (12 and 30 degrees Celsius), the average American’s added-sugar intake rises by roughly 0.4 grams per degree Fahrenheit (0.7 grams per degree Celsius) per day. At 54 F the average added-sugar intake measured was slightly more than 2 grams a day; at 86 F it was more than 15 grams. The team said intake declines above that high-temperature range.

The authors linked weather records — including wind, precipitation and humidity — with detailed purchase data from between 40,000 and 60,000 U.S. households from 2004 through 2019, excluding the pandemic years, and matched those purchases to nutritional information. That approach, lead author Pan He, an environmental scientist at Cardiff University, said, allowed the researchers to isolate the effect of temperature from other factors and estimate a causal relationship and a per-degree change in sugar consumption.

The effect was not uniform across the population. Men consumed more sugary soft drinks overall, and low- and very low-income households showed several times the temperature-related increase in added sugar compared with the wealthiest households. People who work outdoors recorded larger increases than those who work indoors, and households where the head had less formal education experienced greater jumps. The study also found differences by race and ethnicity: White households showed the highest added-sugar response to heat, while Asian households showed no statistically significant change.

"Climate change is shaping what you eat and how you eat and that might have a bad effect on your health," said Duo Chan, a climate scientist at the University of Southampton and a co-author of the paper. "People tend to take in more sweetened beverages as the temperature is getting higher and higher. Obviously under a warming climate that would cause you to drink more or take in more sugar. And that is going to be a severe problem when it comes to health."

The researchers compared their estimates with American Heart Association recommendations of limiting daily added sugar to 36 grams for men and 25 grams for women to contextualize potential health impacts. University of California San Francisco endocrinology professor Robert Lustig, who was not involved in the study, said the daily increase per person is small but cumulative. He noted that among poorer Americans, an additional can of sugary soda per day has been associated with a 29% higher risk of diabetes, and said temperature-driven thirst may be contributing to the nation’s obesity burden.

The paper’s authors and outside experts suggested several mechanisms for the disparity. Sugary beverages are often cheaper and more heavily marketed in disadvantaged neighborhoods, drinking water in some communities is perceived as tasting poor because of chemical contaminants, lower-income households are less likely to have reliable air conditioning and are more likely to perform outdoor work that increases hydration needs.

"It should concern us that the rate of the impact is larger in households where people make less money or are less educated," said Dr. Courtney Howard, vice chair of the Global Climate and Health Alliance and an emergency physician who was not part of the study. "These groups tend to have lower baseline health status, so this is an area where climate-related changes appear to magnify existing health inequalities."

The study also places its findings against the backdrop of long-term warming: the U.S. average annual temperature has increased by about 2.2 degrees Fahrenheit (1.2 degrees Celsius) since 1895, according to the National Oceanic and Atmospheric Administration. The authors warn that continued warming could further raise added-sugar intake driven by temperature, potentially amplifying diet-related health risks over time.

Not all experts viewed the small per-day changes as the most urgent health consequence of climate change. Kristie Ebi, a health and climate scientist at the University of Washington who was not involved in the research, said rising temperatures will bring other acute and chronic health challenges that may be of greater immediate importance than modest increases in sugary beverage consumption.

The study’s authors note that while the individual daily effect is modest, the aggregate increase in added sugar consumption and its concentration in already vulnerable populations makes the finding a public health concern tied to climate change. They said policy responses that improve access to safe, palatable drinking water, reduce targeted marketing of sugar-sweetened beverages in disadvantaged communities, and address heat exposure in outdoor workers and homes without air conditioning could mitigate some of the projected impacts.

The research adds to a growing body of work examining how a warming climate affects diet, behavior and health outcomes, and underscores how climatic changes can interact with social and economic inequalities to influence public health.