The problem is that extraordinary claims require extraordinary evidence.
There are broadly two possibilities:
1. Some unknown phenomenon is defying everything we know about physics. Matter and energy are being created, apparently from nothing. Or perhaps transmutation is occurring without emitting lethal doses of gamma and X-ray radiation.
2. There has been uncontrolled variance due to faulty or incomplete record keeping, unobserved changes in activity, genetic drift affecting the appetite and activity of the population, changes in environment affecting the appetite and activity of the population (eg cage size change, lighting changes, temperature changes), unannounced changes in food supply composition (the food is a commercial product) etc etc et bloody cetera.
In human subjects, when placed in controlled situations, weight loss or gain very closely aligns to the simplest model of calories in - calories out, modulo fluctuations in water weight and personal variations in digestion and activity.
Furthermore, when zoomed out to a population level, BMI tracks calories consumed per capita very closely[1]. The increase in wealthy country population obesity reflects that food is cheaper, easier to get and more calorically dense that at any time in history[2].
Calories in/out is reductionist. But it's all you need to control weight.
> 1. Some unknown phenomenon is defying everything we know about physics.
You have entirely missed the point if you are arguing about physics when discussing this. It is like stating tornadoes occur because the wind moves faster.
When one has data a theory doesn't explain, you hypothesize, and re-test. That's science. Regardless of whether you have convenient correlations like your 1 and 2, you don't assume those correlations are causation and stop researching. What you don't do is dismiss the outlying data and call it a day.
But that's the point: when people or animals are placed under controlled conditions specifically to measure changes in mass vs caloric balance, it all averages out as expected. The samples in this study come from a mix of uncontrolled wild populations living in contact with humans and from captive populations who were not subject to a long term control.
In science you don't get to declare any old thing you like and then everyone else has to immediately agree to test it. Everyone else is free to propose other hypotheses that fit the facts and it is generally accepted that the simplest hypothesis consistent with the evidence is more likely to be correct.
The concept of a viral or epigenetic effect on either the efficiency of digestion or the efficiency of metabolism is worth investigating. However it would require a complicated mechanism to explain how and why it happened simultaneously across a mix of populations. Another explanation, given that all these populations are in contact with the human food supply, is that the human food supply has changed to be more calorifically dense. And, of course, it may be some combination of the above.
A simple way to examine the mystery would be to look at animal populations in other countries. If the wild animal populations of places where people are starving to death are becoming obese, there might be something to it.
> But that's the point: when people or animals are placed under controlled conditions specifically to measure changes in mass vs caloric balance, it all averages out as expected.
No, that's not the point at all. Whether something is causing a greater appetite is the point.
There are broadly two possibilities:
1. Some unknown phenomenon is defying everything we know about physics. Matter and energy are being created, apparently from nothing. Or perhaps transmutation is occurring without emitting lethal doses of gamma and X-ray radiation.
2. There has been uncontrolled variance due to faulty or incomplete record keeping, unobserved changes in activity, genetic drift affecting the appetite and activity of the population, changes in environment affecting the appetite and activity of the population (eg cage size change, lighting changes, temperature changes), unannounced changes in food supply composition (the food is a commercial product) etc etc et bloody cetera.
In human subjects, when placed in controlled situations, weight loss or gain very closely aligns to the simplest model of calories in - calories out, modulo fluctuations in water weight and personal variations in digestion and activity.
Furthermore, when zoomed out to a population level, BMI tracks calories consumed per capita very closely[1]. The increase in wealthy country population obesity reflects that food is cheaper, easier to get and more calorically dense that at any time in history[2].
Calories in/out is reductionist. But it's all you need to control weight.
[1] http://wholehealthsource.blogspot.com.au/2012/06/calories-st...
[2] http://www.ncbi.nlm.nih.gov/pubmed/19828708