Only 2.7 percent of adults in the U.S. were sufficiently active, ate a healthy diet, did not smoke and had a recommended body fat percentage, according to an analysis of National Health and Nutrition Examination Survey (NHANES) data.
The researchers also found an association between the presence of the healthy lifestyle characteristics and cardiovascular disease biomarkers such as cholesterol, blood pressure and glucose.
Lead researcher Paul D. Loprinzi, PhD, of the University of Mississippi, and colleagues published their results online in Mayo Clinic Proceedings on March 22.
The researchers noted that consistent physical activity, not smoking and a healthy diet have been shown to help reduce cardiovascular disease and improve serum cholesterol levels, blood pressure and blood glucose levels.
In this study, they evaluated NHANES data from 2003 to 2006 because that was the only time period during which physical activity data was publicly available. The 4,745 participants were sampled from 15 geographic areas in the U.S. and were examined in a mobile examination center by NHANES personnel.
To measure physical activity, participants were instructed to wear an accelerometer during all activities except water-based activities and when they slept. They were classified as being physically active if they had at least 150 minutes per week of moderate to vigorous physical activity.
Participants were considered as eating a healthy diet if the average of their two-day Healthy Eating Index score was in the top 40 percent of scores. The researchers also measured participants’ serum cotinine, which is a biological measure of smoking status. In addition, they measured the participants’ body fat percentage and considered a normal range as 5 percent to 20 percent for men and 8 percent to 30 percent for women.
Further, they measured the following cardiovascular disease biomarkers that had been shown to be associated with physical activity, diet, body fat percentage and smoking: mean arterial pressure, C-reactive protein, white blood cells, total cholesterol, high-density lipoprotein (HDL) cholesterol, total cholesterol to HDL cholesterol ratio, fasting low-density lipoprotein cholesterol, fasting triglycerides, fasting glucose, fasting insulin, insulin resistance, hemoglobin A1c and homocysteine. All of the biomarkers except for mean arterial blood pressure were assessed from a blood sample.
Of the participants, 71.5 percent did not smoke, 37.9 percent consumed a healthy diet, 9.6 percent had a normal body fat percentage and 46.5 percent were sufficiently active. Further, 2.7 percent had all four healthy lifestyle characteristics and 11.1 percent had none of the healthy lifestyle characteristics.
Women were more likely to not smoke and eat a healthy diet and less likely to be sufficiently active compared with men. In addition, adults who were 60 years old or older had fewer healthy lifestyle characteristics compared with adults who were between 20 and 39 years old.
After adjusting for age, sex, race/ethnicity and other variables, the researchers found that participants with three or four healthy lifestyle characteristics had more favorable levels of each cardiovascular disease biomarker except for mean arterial blood pressure, fasting glucose and HbA1c compared with those with no healthy lifestyle characteristics. Further, participants with one or two healthy lifestyle characteristics had several favorable cardiovascular disease biomarkers, including C-reactive protein, white blood cells, HDL cholesterol, total cholesterol and homocysteine, compared with those with no healthy lifestyle characteristics.
The researchers said that the cross-sectional design of the study was a limitation because it prevented inferences regarding temporality and causality. They said that future research on cardiovascular disease health outcomes may want to focus on comparing objective and subjective models of healthy lifestyle characteristics.
“Although having multiple healthy lifestyle characteristics is important, specific health characteristics may be more important for particular cardiovascular disease risk factors,” the researchers wrote. “Future research is needed to identify effective strategies to increase the adoption of multiple healthy lifestyle characteristics among adults.”