Is procrastination associated with overweight? I came to think of how working out requires a will to "get things done". Some people are successful in their career while working regularly out at the same time, and some people are procrastinating both exercise and career related actions. To "get things done" often takes some physical effort as well, which may make a difference in body fat.

Is there be an association between overweight and general procrastination/lack of motivation?
No. An association between overweight and procrastination appears to have no direct empirical support to speak of. 

The most direct evidence I can find on the matter was a study into industrial workplace productivity's association with overweight, which found a very small (approximately 1%) loss in productivity over other workers associated with moderate or extreme obesity, but this was explained in terms of decreased ability and increased time to perform physical tasks (Gates et al., 2009) rather than self-regulation, motivation or time management. In particular,


  Moderately or extremely obese workers (BMI 35) experienced the greatest health-related work limitations, specifically regarding time needed to complete tasks and ability to perform physical job demands. 


It does appear there have been some conceptually similar economics investigations into whether overweight is associated with engaging in hyperbolic discounting more generally (Scharff, 2009), but overall, there does not seem to be any empirical reason for believing that overweight is associated with procrastination in any practically meaningful sense.

References


Gates, D. M., Succop, P., Brehm, B. J., Gillespie, G. L., &amp; Sommers, B. D. (2008). Obesity and presenteeism: the impact of body mass index on workplace productivity. Journal of Occupational and Environmental Medicine, 50(1), 39-45.
Scharff, R. L. (2009). Obesity and hyperbolic discounting: Evidence and implications. Journal of Consumer Policy, 32(1), 3-21.