Food for thought

I dropped into our deli for a coffee and what should be sitting on the counter but a big fat sweet cheesecake, last seen (or its identical twin) being eagerly devoured by rats.

Did anyone else watch the Horizon programme Sugar v. Fat? The gimmick was to put two young doctors - identical twins - on contrasting diets, one high in sugar, the other high in fat, for a month and see what effect it had upon them according to a series of tests and measurements.

The results were oddly inconclusive. Contrary to expectation perhaps, the twin whose diet was high in carbs lost weight and, boosted by a brief sugar buzz, performed better in physical and mental tests. The twin who gorged on fat gained weight, felt sluggish, functioned more slowly and was found to be so short of insulin that he had entered a pre-diabetic state.
Neither guinea pig enjoyed the experiment: the one who could eat as much as much bread, pasta, cake, sweets, fruit and juice as he wished found that he craved for some grease to help the starch go down, while the twin whose meals consisted mainly of meat, cheese, butter, milk and eggs was desperate for something doughy to soak up the fat. Their appetites were jaded and they had no desire to overeat.

As if we didn't know: it's a balanced diet that is the healthy one. Our bodies seem to have found ways, not necessarily helpful ones, of compensating for high levels of fat and sugar. But this doesn't answer the question why some people do eat to excess and put on masses of weight. The explanation may lie in research being done into the eating behaviours of lab rats who are given a choice of 'junk food' and 'salad bar' meals. Their appetite for the former is such that even electric shocks don't deter them. If allowed free access to a high calorie diet they become obese and sluggish - but they continue to go back for more, topping up at frequent intervals just as compulsively as if driven by addiction (it is a form of addiction to the dopamine rush.) The key to this seems to be the combination of fat and sugar which is incredibly moreish but doesn't occur naturally so our bodies don't have a way of dealing with it: there is no cut-off mechanism. Sugar and fat alone are barely palatable and we have no desire to eat much of them but together* they become irresistible: think ice cream, chocolate and other confectionery, doughnuts, milkshakes - and cheesecake! It's roughly 50:50 fat to sugar and laboratory rats can't get enough of it.

Well, I resisted but I have to confess to having a pastel de nata with my coffee instead. I don't think rats have discovered those yet.

[There is plenty about junk food 'addiction' on the internet for example [url=http://www.scripps.edu/news/press/2010/20100329.html]here[/url].]

* All the foods containing fat and sugar together are manufactured ones of course. Huge profits are made from that irresistible combination.