Women start out with the perception that beauty is an important success attribute which is not so prevalent in males. Women have an incentive to follow healthier diets to maintain their competitive advantage over others. At this stage there is a great interest in different diets, eating regimens and supplements. Thus the overall shift of the curve towards a healthier heart lifestyle. Once menopause takes effect this incentive is reduced considerably, but sometimes the dietary habits remain.
Men on the other hand have a perception about performance (speed, strength, agility) as an important success attribute. Men tend to follow diets high in energy that generate the calories needed for high performance. Unfortunately these diets are exactly the ones that cause heart problems in the long run. These dietary habits are often difficult to change as life goes on and lead to serious congestive problems.
There are non-competitive males and females that don't fall into these categories of behavior. Also as people get older, or get married they tend to fall out of these diverse behaviors and follow similar diets (mostly unhealthy). I think that people that realize how their diets are affecting their health can move into healthier lifestyles, but it's a significant effort to make the change.