There are many reasons that there are more over-weight people now than in the past. Here's a few:
EXERCISE:
This generation is hooked on laptops, computers, cell phones, television, game console, portable games, etc. Kids will literally sit up all night playing games or on their phone, which is why they're not getting enough exercise. Lack of exercise can lead to obesity.
UNHEALTHY DIET:
There are new foods coming out all of the time. You see all there Wendy's, Burger King's, McDonald's', etc. commercials every other day competing to get you to eat unhealthy foods. The bad part about it, some parents give their children fast-foods every night to eat instead of cooking, so sometimes it's not entirely the child's fault.
GENETICS:
Your genetics play a role in how much fat your body stores. Two people could eat the same thing every single day, and it would be very possible for one person to weigh more than the other.
MEDICAL PROBLEMS (and DISABILITIES):
Some people simply cannot exercise like others. There are diseases out there that can cause shortness of breath, fatigue, etc. Keep in mind that this subcategory also includes paralyzed people.
