Humanity's Biomass And The Environment

When trying to get my head around just how many of us call this planet home and how to visualize those numbers a different way, I did some back-of-virtual-envelope calculations relating to human population a few years back; one of them relating to the biomass of humanity.
A new study has gone about determining human biomass in a more accurate way – and the results are disturbing.
The weight of nations: an estimation of adult human biomass” states in 2005 global adult human biomass was approximately 287 million tonnes. My figures were comparatively very, very conservative; particularly considering mine included children.
The study’s figure is interesting on its own – the sort of trivia you can drop in on dinner party conversation; but another figure in the report signifies something more important.
15 million tonnes of that figure was due to excess fat. Try to imagine 15 million tonnes of fat – it’s pretty hard to as it’s such a large amount.
15 million tonnes represents a mass equivalent to that of 242 million people of average body mass, or 5% of global human biomass at that time. The issue with burgeoning waistlines has only gotten worse since 2005 too.
Putting aside issues of health, there are major ramifications for the environment. Fat is stored energy. That energy has been stored courtesy of excess consumption. Consumption impacts natural resources; everything from the amount of land we need to grow food, to the chemicals applied, to shipping food and packaging it.

So much food is being turned into body fat that isn’t needed – and it also takes energy to carry all that excess weight around.
There’s also other hidden problems not mentioned or accounted for in the study. 
For example, the common wisdom is if you’re going to eat more, do more. When doing more consists of non-productive activity – such as use of treadmills and other equipment; it’s a little like filling your car up with gas and then leaving it sitting in your driveway idling.
Don’t get me wrong – exercise is very important and diet/exercise regimes to pull off pounds have an important role; but some  people of normal weight who rely on high levels of non-productive exercise on an ongoing basis to stay trim are having an impact on the environment similar to that of overweight people.
Additionally, while every minute of our waking day shouldn’t have to be productive; our focus on recreation, relaxation and sport is having a major impact in this regard too. Sadly, many of us have forgotten there can be great joy as well as health, community and environmental benefits in useful productivity. 
Exercise and the environment
Population management – ultimate greening
Visualising population