Lifestyle Intervention With Physical Activity and Diet for Precision Health in Individuals With Overweight: a 6-month Pilot Randomized Controlled Trial (LI-PAD)

Individualized lifestyle Intervention with Physical Activity and Diet as precision health in individuals with overweight: a 6-month pilot randomized controlled trial (LI-PAD)

BACKGROUND Individuals with obesity and type 2 diabetes have an increased risk of cardiovascular disease (CVD). Lifestyle changes with physical activity (PA) and diet have been associated with temporary improvements in these risk factors. However, sustained behavior changes are difficult to achieve. In Sweden and globally, the built environment promotes overweight and obesity through high availability of cheap ultra-processed energy-dense foods and drinks and low possibility of physical activity. Although the recommendation is to apply an individualized approach, few studies have applied this in clinical practice. PA on prescription, using an individualized approach, has been partly implemented into Swedish health care, resulting in short- and long-term favorable effects of PA. However, an individualized approach to modifying diet has not yet been incorporated, despite evidence showing that interventions targeting PA and diet together have a greater effect on obesity. Another crucial limitation is that PA and diet recommendations are not developed for individual application.

Previous research has shown that it is important to consider individual adaption to medical conditions (e.g. risk profile, symptoms, comorbidities) and to psychosocial factors (e.g. preferences, barriers-facilitators, readiness-to-change). It is also know that individuals require support for behavioral change (e.g., counseling/coaching, group activities, education, nudging). Furthermore, there is a link between unhealthy food environments, unhealthy food consumptions, and food-related diseases, but results vary. Previous intervention studies have shown that an unhealthy food environment is a barrier of adherence to intended behavioral changes. However, it is unclear which components are particularly important, how much of each of them should be included, and whether freedom of choice is a more efficient option compared to offering a more standardized solution as in most randomized controlled trials (RCTs).

To prescribe optimal PA for the underlying disease, the investigators are currently developing accelerometer-based PA measures and recommendations adapted to individual fitness. The optimal diet prescription targets weight reduction, primarily as body fat, by restriction energy intake below the energy need. Although rapid early weight loss is important for sustained effects, too great energy restriction (due to unrealistic goals or applying a standard treatment) results in increased hunger and reduced metabolism, not leading to larger weight reduction when clinically applied. Research supports up to 10% weight loss at 6 months by applying a ~500 kcal/d reduction of energy intake below energy need. Energy need is most accurately determined with the doubly labeled water method but is too expensive for clinical use. An alternative method commonly used is to determine resting energy expenditure (REE), calculated from individual characteristics such as body weight, and multiplied with a factor for the PA level. However, REE determined using body weight is not accurate in obesity, and the most optimal equation considering body composition is too imprecise at an individual level. REE based on measured oxygen (O2) and carbon dioxide (CO2) exchange is preferred and can also be used to monitor the respiratory quotient (RQ=CO2/O2), which is an indicator of fat metabolism. Measured O2 and CO2 are inexpensive and can be used together with measured food intake for more individualized diet prescription and to track the effects of the intervention on metabolism and use of body fat.

The present study represents a unique progress of lifestyle intervention programs away from the more standardized randomized controlled trials to approach precision health:1) adaption to medical conditions and psychosocial factors, 2) individualized PA and diet advice based on individual and environmental measurement, 3) aids for achieving goals using education, skills training and supports (Figure 1). Although individual adaptions to medical conditions and psychosocial factors are already performed in health care, individualization of PA, diet, and support for behavioral change has rarely been implemented and evaluated. This individualization requires additional resources in health care. Therefore, it is important to determine the benefits of this approach and in future studies also follow up with cost-benefit analyses.