I would think that there are definitely more fat people now than what there were decades ago, but from what I can understand of the situation; the average person has not significantly increased their calorie intake from decades ago, but has significantly decreased their daily exercise.

So by the end of the day, there is often a net gain in calories.

I think this is why diets are rarely successful, because people do not exercise enough to reduce weight, even with a reduced calorie intake.

The situation will require much government and community initiative to correct.

Work is requiring less manual labour, and work at home is also reducing in the amount of physical effort required.

So in the future, work by itself will not be sufficient to burn up the calories

The obesity pandemic has many dimensions and accordingly many strategies will be needed.

One of the major challenges will be to move our illness industry to a health system. We tackle problems decades too late. It makes no sense to start newly diagnosed Type 11 diabetics, many of whom will be severely obese and unable to do the recommended 30 minutes of moderate activity a day and some will also have the depression that comes with chronic disease and makes it hard for them to get up and exercising, on a new lifestyle. How much better it would have been be to get them twenty years earlier while they were merely overweight and capable of doing sufficient physical activity to tackle the problem.

Sadly our GPs are not paid when their patients are well (which after all is what we all want from them) but rather they attract more money through consultations when their patients are ill. It is also sad that general practices cannot afford to employ allied health practitioners (such as nutritionists, psychologists, and exercise physiologists) so that they can work proactively as a team to tackle overweight and obesity. They have the potential to reduce hospital expenditure on treating chronic diseases by up to 70%.

Political leadership is badly needed to focus on the important issues and to get their health bureaucracies to focus on wellness rather than illness.

One of the major contributor to obesity is human unhappiness. When instead of playing one decide to eat there is something wrong with the psyche.
With a fresh midwife diploma I visited the Soviet Union in 1965. Crossing the Red Square to see Lenin in the Mausoleum I was startled by the number of grossly obese people around me. The enormous grip of communism on the life of ordinary Russians increased the size of void within themselves to such a level that consciously or unconsciously they were ready to "sign out."
Returning to my own country somewhat more aware I noticed the same level of obesity. My mother greeted me with the fact that we have potatoes for dinner. Nothing more than potatoes! No salt, pepper or oil to improve the humble spud.
The government of Australia is also guilty for unhappiness in society.
We might have more than potatoes for dinner but the working conditions in this country are so bleak that when one finally arrives home collapses into obsolescent.
A good government would be able to eradicate most of human misery regrettably, the next one will be the same as the present one.

First of all please allow me to agree with HRS and the in/out theory, it has been a personally observed one of mine for a very long time. The other two theories expressed have their merits but appear to be a tad Lefty for me personally.
Doctors, the Gummint or any other entity are not responsible for initialising, reducing or maintaining an individuals personal weight. The individual is!
If a person is fat/obese/weight-challenged or whatever defines overweight, then it is that persons individual challenge to lose it and not to sit on their bum - where many problems begin - and wait for someone else to intervene.
Having said that, the individual should, by all means utilise the facilities provided by GP's, community and health organisations etc but GO TO THEM, don't sit and weight for them to come to you.

Individuals certainly are responsible for their health - but up to a point. You see, Australia is facing severe problems with childhood obesity and children can't make the same informed choices as adults can. If the family meal is loaded with fat they still have to eat it or starve. Worse still, some parents believe certain foods are nutritious when in fact they are high in fat. So unknowingly, the children increase their fat intake until there is a serious problem. There is also the issue of school canteens serving little more than junk food.

I have no quick fix to the obesity problem in Australia (if I did I'd be getting the Nobel Prize). It's a combination of factors which Dr Leeder has alluded to.

The way forward seems clear to me. Something along the lines of the North Karelia project which presents a total package by way of addressing all the significant contributors to obesity. If this project can lower heart disease in men aged 35 to 64 by 57% from 1970 to 1992, in a society similar to ours, then its gotta be good.

I am an ardent advocate for an urgent conversion of our society onto a genuine sustainable footing. Our health and wellbeing lies at the very core of a sustainable society. So addressing the obesity epidemic has got to be an integral part of this push.

Sure it will be difficult. Personal responsibility is a large part of this issue, and even with the best social support mechanisms, it will be hard to get a considerable proportion of obese people to look after themselves properly.

One of the key things for the new Rudd government will be to fight the profit motive and pressure from big businesses that make their money out of unhealthy food, and to uphold the ‘health and wellbeing’ motive as our bottom line. That will be a big challenge in a society that is so strongly dominated by big vested-interest business. But it can be done!