Regarding number one, not only are people eating "comfort food" because
of their high stress levels. The longer working hours and longer
commuting time means less time to get exercise.

I'll add a couple:

6) Your body hungers for nutrients as well as calories. If you fill
it with high calorie, low nutrient food (ie. junk food) you will still
be "hungry" and tend to overeat. If you eat quality (high nutrient
value) food, you will be satisfied with less.

7) Especially for women, there is a huge pressure to be THIN. It's
not unusual for girls to start dieting when they're in elementary
school. This messes up their natural metabolism and starts a lifetime
of yo-yo dieting, where they always gain a little more than they lost.
I think the constant emphasis on thinness also makes some women just
give up. "I can't be a size 8, so I might as well be an 18" mentality.