I'd say without a shadow of a doubt, yes, there are many many factors.

Increase in ready availability of "foods" full of empty calories and various unhealthy fats, also with high salt content and including additives to supress feelings of fullnessd and encourage greater consumption that would otherwise be necessary to sate hunger is probably one.

This increase may have a causative link to another observed phenomenon, which itself could be contributing to decreased healthyness; people cooking at home less, particularly people who do cook at home using things like sauces they™ve bought in jars rather than made themselves.

I hasten to add that I don™t intend to sound critical, though I™m aware that I probably do.

But by not starting from the very beginning, say buying a lasagne sauce even if you do the rest of it yourself, you™re not entirely in control of how much salt or whatever is in the final dish. I read advice somewhere, I forget where, that you shouldn™t buy anything that lists ingredients you wouldn™t add if you were to make the thing yourself. I can™t say it™s advice I™ve taken to heart entirely, but it has made me think a bit more.

Another potential cause could be the increase in popularity and variety of available video games and other sorts of œpassive home entertainment " stuff that involves sitting down, and can usually be accompanied quite easily by the consumption of yet more snack food.

This, along with a rise in office based jobs that again mostly involve sitting down comes under the heading a œsedentary lifestyle.

The increase in office based jobs in many cases has also lead to increased disposable income (allegedly), which again means more computer games, more bought rather than made food, people more likely to drive than walk somewhere.

Another potential scapegoat would be lack of time " people are so busy working to get the money to buy to ready made food and run the car and supplyly the demand for home entertainment solutions (not just computer games, but home computers with access that there interweb, movies, box sets of dvds, even my personal favourite - good old fashioned books, which much as I love them and strongly as I feel that reading is essential for a healthy mind, it™s not the easiest of activities to combine with the movement that™s necessary to cultivate a healthy body) that they don™t have time to cook from scratch, or walk instead of driving, or grow their own food, or are too tired to do anything too strenuous when they get home. Part of this is a perceptional issue " it may not actually take significantly longer to cook from scratch than to buy and oven something ready made, but people think it will, or it that it will be difficult or boring and that by not doing it they free up time they could spend doing something they would enjoy more. Whatever. I haven™t done nearly enough research or reading of other people™s research into this to have a properly informed opinion.

The above are all broadly economic developments.

There are others, but I'm short on time now.