The truth about humans - are we evolving or devolving?

What are the distinct characteristics that define a human? Is the human race evolving or devolving? In line with the saying ‘you reap what you sow’, I believe that in our race for evolution, we have successfully sowed the seeds of devolution. With the possible exception of the African continent, I believe that obesity is a major health concern faced by countless nations across the globe. Obese people have higher risks of being afflicted with:
* Cardiovascular diseases due to high blood pressure and high cholesterol levels.
* Diabetes
* Osteoarthritis
* Cancer

While it is true that the average lifespan for humans has increased tremendously from 47.3 years in 1900 to 77.8 in 2004 (from U.S. Statistics http://www.cdc.gov/nchs/data/hus/hus07.pdf#027) mainly due to the advancement of medical sciences, advancement in general technology has led humans to lead a more comfortable live due to less physical exertion. It is because of less physical exertion that is directly contributing to the ‘devolution’ of the human race. Are these diseases a result of evolution of devolution?

In line with the saying ‘what goes up must come down’, isn’t it possible that by reaching the peak of evolution, the human race must face devolution? Surely after 6,000 years of recorded human civilization, the human race has evolved near peak levels? Take for an example in the Beijing Olympics 2008, where Michael Fred Phelps (http://en.wikipedia.org/wiki/Michael_Phelps) won the most number of gold medals at a single Olympics, a total of eight. In terms of human physique, if this is not an indication that the human race has evolved to near peak levels, I do not know what this is.

In terms of scientific advancement, physicists have made many breakthroughs in quantum physics to the extent that even the smallest building block particle has been proven to exist. In fact, scientists are building a USD8 billion international physics laboratory called CERN (http://www.npr.org/templates/story/story.php?storyId=9473392). In terms of economic activities, the numbers of billionaires are increasing annually. In terms of academic achievements, the students are continuously creating new academic records. In every single field of study, new records are being created. If these are not indications of human evolution are near peak levels, what are they?

To quote the following sayings:
* We have eyes but we choose not to see
* We have ears but we choose not to hear

* We have limbs but we choose not to act

What are the corrective actions for us to implement if the continuous evolution will mean devolution for the majority of the global populace? Perhaps we should research into making daily tasks more physically challenging? I have no answers, only more questions. Do share your thoughts.