A worrisome increase in obesity levels in much of the world suggests that current methods of motivating people to eat healthier food and get more exercise are not all that successful. Much of today's research focuses on ways of delivering messages in order to obtain the best sustained adherence to these two key health behaviors. One such study by Abby King and colleagues from the Stanford School of Medicine in California looks at the timing of giving exercise and nutrition advice. The researchers found that a higher success rate might be possible when the advice is given at the same time. Their study is published in Springer's Annals of Behavioral Medicine.
Given the busy and stressful lives many people lead, advice on healthy eating or physical activity often ends up being just another source of stress. Many health professionals believe that people find multiple messages overwhelming and this has led to an emphasis on making small changes, one at a time. However, some researchers suggest that this method may actually end up reducing compliance. Each subsequent change requires another bout of motivation which may, by then, be in short supply. The current study was therefore designed to systematically test one method against the other to see which might be more beneficial long-term.
The researchers divided 200 participants into four groups. All participants were aged 45 years and older, did little exercise, ate fewer than five fruit and vegetable portions per day and had a higher than recommended saturated fat intake. They also reported elevated stress levels. The four groups were given differing sequences of telephone-based advice: one group received exercise advice first, then nutrition advice was added after four months; a second group was given nutrition advice first, then exercise advice was added after four months; the third group received simultaneous delivery of nutrition and exercise advice; and a control group was advised on stress management only.
While all three groups showed positive increases in their dietary patterns relative to controls, there were differences in success when it came to physical activity. Participants who had received the exercise advice first significantly increased their physical activity levels at four months relative to controls, whereas physical activity did not increase significantly in the 'simultaneous' group at this early stage. However, by 12 months, both the exercise-first and simultaneous groups had increased their exercise to the nationally recommended levels.
In contrast, the group obtaining the nutrition advice first was not, on average, able to increase their exercise to the recommended levels by 12 months. Those in the simultaneous group were the only ones who succeeded in meeting the national recommendations for both dietary and physical activity behaviors at 12 months.
These results suggest that it may be easier to incorporate changes in eating habits than exercise, particularly when eating patterns are targeted at the beginning of a program. This could be because eating is already a scheduled activity. Adding physical activity to an already busy schedule may be more difficult, especially when people are attempting to change their eating habits as well. Focusing similar attention on both health behaviors from the start may signal the importance of making both a priority.
According to the authors, "The results suggest that, in the current population, delivering physical activity and dietary interventions simultaneously may result in the most positive sustained outcomes across these two important health behaviors." Similarly, the potential interference effects of early dietary intervention on subsequent physical activity changes merit further study.
King AC et al (2013). Behavioral Impacts of Sequentially versus Simultaneously Delivered Dietary Plus Physical Activity Interventions: the CALM Trial. Annals of Behavioral Medicine DOI 10.1007/s12160-013-9501-y
The full-text article is available to journalists on request.