A recurrent theme in Roman political thought inhereted from the Greeks, as almost everything of theirs was, was luxury and the possibility for luxury to corrupt. Specifically to corrupt a person's public spirit or the general aim of perfecting themselves (the Greek notion of arete). So Caesar was cautious of the potential contained in evidently ambitious men who were not letting themselves go in luxury as they were potential rival tyrants, or they could be those who wished to restore a more Athenian mode of governance... It turns out there were plenty of both types around.

A related notion from the ancient world:

http://en.wikipedia.org/wiki/Tall_poppy_syndrome

From William Shakespeare's Julius Caesar, Act I, Scene 2:

  CAESAR
  Let me have men about me that are fat;
  Sleek-headed men and such as sleep o' nights:
  Yond Cassius has a lean and hungry look;
  He thinks too much: such men are dangerous.
  
  ANTONY
  Fear him not, Caesar; he's not dangerous;
  He is a noble Roman and well given.
  
  CAESAR
  Would he were fatter! But I fear him not:
  Yet if my name were liable to fear,
  I do not know the man I should avoid
  So soon as that spare Cassius. He reads much;
  He is a great observer and he looks
  Quite through the deeds of men: he loves no plays,
  As thou dost, Antony; he hears no music;
  Seldom he smiles, and smiles in such a sort
  As if he mock'd himself and scorn'd his spirit
  That could be moved to smile at any thing.
  Such men as he be never at heart's ease
  Whiles they behold a greater than themselves,
  And therefore are they very dangerous.

It has to do with men who have the ability to over-indulge or be lazy (and get fat) but have the strength to avoid such activities.

Physical strength is not a factor in this. It is strength of the mind.

>>>men who have the ability to over-indulge or be lazy (and get fat)

No. Not everyone can get fat. I know this. I'm one of them. And yes, Caesars throughout history should fear people like me. Because we're gunning for their pompous, smug, fat, lazy asses. Aside from their flabby souls, their physicality aesthetically disgusts us,

Shut up you idiot. First, you're missing more than half the point and im not going to explain. Reread 3 times then try again.

Speaking to your personal anecdote you view as fact, Or your metabolism has just been good with whatever you've thrown at it, and you've never put it into a state of shock to cause one of the many means of retention.

Alternatively you can go with, CALORIES IN CALORIES OUT. CANT EXPLAIN THAT.

You may want to look at the guidelines again. The relevant one in this case is "When disagreeing, please reply to the argument instead of calling names. E.g. "That is an idiotic thing to say; 1 + 1 is 2, not 3" can be shortened to "1 + 1 is 2, not 3.""

I see I touched a nerve here. Apologies to anyone who took offense. I meant it in a Seven Deadly Sins sense, although the heat I put into the comment made it seem like I even hated Santa Claus!

In Caeser's mind, the main perk of power is more delicious food. Someone uninterested in this can't be tempted or manipulated.

Perquisite, not prerequisite. Perquisite means something like "perk".

It's actually the origin of "perk" as in "job perks" (as opposed to "perk" as in "stand up straight" or "be lively").

All men are hungry. What separates the dangerous from the docile is what one feeds this hunger with - political power or food, in Caesar's case.