Final answer:
Obesity is influenced by dozens of genes related to appetite and metabolism. This genetic predisposition, coupled with environmental factors like diet and physical activity, contributes to its development. An exact count of genes is not determined due to the complexity of the interactions involved.
Step-by-step explanation:
The predisposition to obesity is connected to a number of genes that influence appetite and metabolism. When there is an excess of food energy available, these genes may increase the likelihood of developing obesity. Studies have shown that obesity tends to run in families, suggesting a strong genetic component. If both parents are obese, there is an 80 percent chance that their children will also be obese. Conversely, if both parents are of normal weight, the chances of their children becoming obese drops to less than 10 percent. This familial trend underscores the impact of genetic factors on obesity. Environmental factors also contribute significantly, including diet and physical activity levels. With modern changes in diet, such as increased calorie consumption—often from carbohydrates and sugary drinks—and sedentary lifestyles due to technological jobs, the rates of obesity have climbed. Furthermore, factors like socioeconomic status and lack of safe environments for physical activity can contribute to the risk of obesity.
While there are certainly dozens of genes that contribute to the predisposition to obesity, the exact number is difficult to pinpoint as research is ongoing. Some specific genetic conditions, such as Prader-Willi syndrome, clearly illustrate how genetic changes can directly lead to obesity. However, most cases involve a complex interplay between multiple genes and environmental factors, making it a challenge to determine the precise number of genes involved.