Final answer:
In the list of factors contributing to the increase in obesity, significant shifts in genetic risk are not considered a contributor, as genetic changes happen over extended timeframes, not short-term increases. Other listed factors such as the food environment, physical activity, and dietary habits are contributors to the growing obesity rates.
Step-by-step explanation:
The factors believed to play a part in the increased rates of obesity in the United States include the food environment, fewer sidewalks and parks, sleep deprivation, and fewer home-cooked meals. However, among the options provided, significant shifts in genetic risk are not considered a factor contributing to the recent rise in obesity. This is because genetic changes occur over much longer periods, and the increase in obesity is too recent to be attributed to significant genetic alterations.
Causes of obesity are multifaceted, often involving an interplay between genetic and environmental factors, such as excessive food intake, inadequate physical activity, and to a lesser degree, genetic susceptibility.
Public health approaches on obesity focus on understanding and correcting environmental factors, including promoting healthy meals, limiting access to unhealthy options, and promoting physical activity by increasing access to areas like parks and pedestrian routes.