If one or both of your parents struggle with weight, a genetic basis for difficulty losing weight is a strong possibility.

CNN: I'm exercising; why can't I lose weight?

It also provides an objective basis for asking board members to leave if they are not pulling their weight.

FORBES: What Every Nonprofit Board Needs to Know

On a daily basis, it seems clear that the timing of meals plays a role in how much weight you gain.

FORBES: Holiday Overindulgence Got You Down? Blame Your 'Food Clock'

Professional body builders consume up to 1.5 grams of protein per kilogram of weight each day, but unless you are spending several hours in the gym on a regular basis, this is too much for the average person trying to gain muscle.

CNN: How should I eat to build muscle mass?

For instance, instead of using market capitalization as a basis for portfolio positions, some newer ETFs use other financial measures, such as revenue or dividend rates, to weight their holdings.

WSJ: New Index Funds: The Inside Story