Adults with a high-quality diet and sufficient physical activity are less likely to have been hospitalized than those lacking in both, according to a new study. Having only a high-quality diet or only sufficient physical activity showed no statistically significant difference in the overall analysis.
Seoul National University Hospital said on the 14th that a research team of family medicine professors Park Min-sun and Kim Kye-hyung, along with clinical instructor Kim So-young, reached the finding after analyzing the link between eating habits, physical activity and health care use among 37,059 adults, using data from the Korea National Health and Nutrition Examination Survey.
The team assessed diet quality and physical activity levels among adults aged 20 and over who took part in the survey from 2014 to 2021. Diet quality was divided into high and low based on the median score of the Korean Healthy Eating Index (KHEI). For physical activity, leisure-time activity including walking was converted into moderate-intensity equivalents, and those logging 150 minutes or more per week were classified as active. Moderate intensity refers to activity that leaves a person slightly short of breath.
The team then combined the two criteria to sort participants into four groups. Using the group low in both diet quality and activity as the reference, the researchers compared it with the group high only in diet quality, the group sufficient only in activity, and the group meeting both standards. Health care use was measured through survey responses on hospitalization within the past year and outpatient visits within the past two weeks.
The analysis found that the odds of hospitalization in the group with both a high-quality diet and sufficient physical activity were 11% lower than in the reference group, with an adjusted odds ratio of 0.89. Odds refers to the probability of having been hospitalized divided by the probability of not having been. The adjusted odds ratio for the group sufficient only in physical activity was similar at 0.90, but the result was not statistically significant. The group high only in diet quality came in at 1.02, little different from the reference group.
Broken down by participant characteristics, the link between physical activity and hospitalization was clearer in some groups. Regardless of diet quality, the odds of hospitalization among the active groups were 15% to 18% lower for patients with chronic illness, 18% to 22% lower for women and 28% to 30% lower for those aged 65 and over. By contrast, no statistically significant link was found among men, adults under 65 and people without chronic illness.
Outpatient visits showed a different pattern from hospitalization. Groups with a high-quality diet were in fact more likely to have received outpatient care. Compared with the reference group, the adjusted odds ratio for outpatient visits was 1.19 in the group high only in diet quality and 1.09 in the group meeting both diet and activity standards.
The team said people with a high-quality diet may pay more attention to their health in general and therefore seek medical care more actively. It also raised the possibility that people whose physical activity is limited by illness received outpatient care more often. That means a higher number of outpatient visits alone is difficult to read as a sign of worse health.
"Rather than addressing better eating and more physical activity separately, we need an integrated health promotion strategy that targets both together," Park said. "In particular, women, older adults and patients with chronic illness, who bear a heavy hospitalization burden, need to be given priority."
The study was cross-sectional, however, and does not prove that eating habits and physical activity directly reduce hospitalization. The possibility that illness reduced activity levels cannot be ruled out. The findings were published in the latest online edition of the international journal Preventive Medicine Reports.
