In the classic Monty Python 1970s movie, The Life of Brian, Brian tells the swarming masses, “You are all individuals,” to which the group responds as one, “Yes, we are all individuals.”
The fact is, we are all individuals and respond differently to different pharmaceutical and lifestyle prescriptions – weight loss being a great example.
But does this mean we need a separate program for all three million overweight or obese adult Australians? And if not, how do we individualise without over-individualising?
The first law of thermodynamics states that energy is neither gained nor lost, it just changes form. We’re told that this is immutable. And yet change the energy balance (food in/exercise out) of 1000 people in exactly the same way and you’ll get a variation in weight loss from nothing, to more than the loss predicted through any calorific formula. The question is why?
The simple answer is that the first law is based on a physics formula, which is linear, eg: weight = energy in – energy out. This only works roughly, in a biological system. Feedback in a living organism, such as through changes in metabolic rate, hunger levels, and a range of other factors, make generic lifestyle prescriptions such as diet and exercise, just that – generic, with huge variations around the mean.
The implications of this are profound. A calorie is no longer a calorie. As the actual value of heat energy can be influenced differently by feedback in individuals, any attempt to prescribe or measure weight gain or loss by counting calories, is bound to be flawed.
Using a systems theory model can complicate the issue, but may be totally necessary. In the UK, the Foresight Commission, a body set up to examine the future, published a diagram of known drivers of obesity