(RxWiki News) Exercise and diet both play a role in physical fitness, but does one trump the other? Perhaps so, according to the researchers behind a long-term study of obesity.
The researchers analyzed data on physical fitness, diet and obesity in people across the US from the years 1988 to 2010.
The study found that obesity rates among Americans of both genders increased during this time. Obesity rates rose particularly among women, and most especially among women who got no physical activity during their free time.
"Try teaming up with an exercise buddy to keep each other motivated."
According to the authors of this study, which was led by Uri Ladabaum, MD, MS, of the Stanford University School of Medicine in Stanford, California, both obesity and greater waist circumference — or "abdominal obesity" — are associated with a number of health risks and even an increased risk for death.
Dr. Ladabaum and team aimed to explore the connection between obesity, physical activity and diet. Diet was measured by means of caloric intake, and obesity was measured using body mass index (BMI), a ratio of weight to height, and waist circumference.
A BMI of 30 is generally considered obese and a waist circumference of greater than 88 centimeters (cm) for women and 102 cm for men is generally considered abdominal obesity.
To analyze these factors, the researchers used data from the the National Health and Nutrition Examination Survey (NHANES) for the years 1988 to 2010. The NHANES surveys include several thousand adults from across the US each year.
Dr. Ladabaum and team found that the average waist circumference of women increased by 0.37 percent per year, and the average waist circumference of men increased by 0.27 percent each year during the course of the study.
The researchers also found that during the time period studied, the average BMI increased by 0.37 percent a year for people of both genders. The group which saw the greatest increase in both BMI and waist circumference measures were young women.
In 1988, 19.1 percent of women reported not participating in any leisure-time physical activity — a number which increased to 51.7 percent by 2010. Among men, the rate of those getting no physical activity in their free time increased from 11.4 percent up to 43.5 percent.
Despite big changes in physical activity levels, Dr. Ladabaum and team saw no major changes in caloric intake levels during the course of the study.
After analyzing the data, the researchers determined that women who reported no leisure-time physical activity had BMIs that were 8.3 percent higher than their counterparts with an "ideal" level of physical activity, which is at least 150 minutes per week of moderate and vigorous physical activity. For men, those with no leisure-time physical activity had BMIs 1.7 percent higher than their more active counterparts.
Dr. Ladabaum and team wrote that their findings suggest the importance of emphasizing exercise in efforts to reduce obesity.
In an interview with dailyRx News, Jim Crowell, owner and head trainer at Integrated Fitness in Pittsburgh, stressed that there are many factors that contribute to health and wellness.
"Health is not something that can be changed in a bubble," said Crowell. "I'm a big believer that you need to exercise consistently, eat healthy far more often than not, and that you need to lessen external stressors to your mind and body.
"The clients that consistently get the best results are those people willing to take a truthful look at themselves and make positive changes in these three areas," explained Crowell.
Crowell told dailyRx News that people looking to start exercising should start slow, but challenge themselves.
"My recommendation is to begin with an easy weight training and aerobic program," said Crowell. "It needs to be easy to keep you excited and it needs to progress slightly harder over time because that is the progress metric and that progress is the entire health goal that people are shooting for."
It is important to note that this study included some data that were self-reported by the participants, including data on caloric intake, which could allow for some error. Further research is needed to confirm these findings.
This study was published in the July issue of the American Journal of Medicine. Some funding for the study was provided by the National Institutes of Health (NIH). No conflicts of interest were reported.