I think that there was a study done showing people who are in shape "appear" to be more intelligent, trustworthy and reliable as oppose to those who are overweight.
Pereception of those who are fit/in shape:
1. More effective at sales/persuasion. (sex sells)
2. More trustworthy and have more discipline as they can manager their own weight.
3. More energy and drive.
4. More reliable in reaching goals.
I'm a little bigger myself, and I know that it does affect an individual especially in the business world.
How many CEO's or top executives have you seen on TV that are overweight. Not too many. There might be a correlation between advanced degrees and weight. Have you ever checked out med, law, or dental schools. All the students are in within normal weight range.
Just some of my insight. I need to hit the treadmill.