Final answer:
The most likely reason that John's generation is more susceptible to illness, such as being overweight, is due to a combination of factors including a less active lifestyle and unhealthy eating habits. Environmental factors and genetic predisposition also play a role in weight gain.
Step-by-step explanation:
The most likely reason that John's generation is more susceptible to illness, such as being overweight, is due to a combination of factors including a less active lifestyle and unhealthy eating habits. Many people in developed countries are living a sedentary lifestyle, spending more time on computers or watching TV rather than engaging in physical activities. Additionally, the availability of fast and cheap meals often leads to consuming foods that are high in fat and calories.
Factors such as socioeconomic status and the physical environment also contribute to weight gain. Living in a neighborhood with limited food options or high crime rates may discourage physical activity and limit access to healthy food choices. Further, genetics can play a role in obesity, as some individuals may be genetically predisposed to gaining weight.