Impact of Calorie Changes in Chain Restaurants on Obesity: A Systems Dynamics Approach
Project Lead: Saeideh Fallah-Fini, PhD
The increased prevalence of obesity in the U.S. affects many different systems around us like the environment, economics and social networks to name a few. Obesity is a significant contributor to factors ranging from an upsurge in health care costs, decreased productivity level for businesses and increased amounts of noncommunicable diseases like diabetes and cancer. Strong evidence shows that exposure to different neighborhood-level environmental characteristics are associated with different health outcomes such as obesity. Within the food environment, restaurants are a particularly important area of focus for public health research, given the concern over the hypothesized contribution of increased restaurant eating and overconsumption of calories to the obesity epidemic. This concern prompted policy action in the form of menu labeling so that consumers could be more aware of the calories associated with each menu option.
Menu labeling was first adopted by more than 20 localities, and then most recently, across the entire country due to the federal 2010 Affordable Care Act (ACA). Originally conceptualized as a tool to give consumers better information about their food purchases, menu labeling aims to provide information on calories, fat, sodium and other selected nutrients.
A recent study examined 66 of the largest U.S. chain restaurants and observed voluntary reductions to the calories in newly introduced menu items by 60 calories from 2012 to 2013. Reducing calories obtained in chain restaurants by approximately 60 calories may help to substantively reduce the daily number of excess calories underlying the obesity epidemic in adults (220 calories per day) and children (165 calories per day). In this project, we aim to estimate the effect of such reduction in daily calorie intake on future prevalence of obesity in the U.S. population.
Phase One: Estimate the energy imbalance gap (EIG) for the U.S. population over the past 40 years. To this end, we will do the following tasks:
- Develop a population-level systems dynamics (SD) model that captures the body mass index (BMI) distribution and obesity prevalence in a population.
- Calibrate the SD model using data from National Health and Nutrition Examination Survey (NHANES) to estimate the EIG that is consistent with the prevalence shifts of obesity in the past 4 decades by gender, race/ethnicity and BMI groups.
Phase Two: Use the SD model developed in Phase One to evaluate the effect of 60 calories per day reduction in energy intake of population on future prevalence of obesity in the U.S. population.
To learn more about this project and find out how to get involved, please email the Global Obesity Prevention Center at Johns Hopkins directly here.