Here is a press release from Monash University (I'd never heard of it either. It is in Australia).
Anyway this is published in Nature - a very prestigious journal - so it must have some rigour. Basically the idea is that this guy has identified a mechanism by which eating carbs can lead to you overeating. It is not about insulin this time but rather about the way in which carbs damage appetite control
Dr Andrews found that appetite-suppressing cells are attacked by free radicals after eating and said the degeneration is more significant following meals rich in carbohydrates and sugars.
"The more carbs and sugars you eat, the more your appetite-control cells are damaged, and potentially you consume more,"
It would be interesting to read the full paper if any one has access to it?
Killer carbs -- Monash scientist finds the key to overeating as we age
Here is the abstract.
The gut-derived hormone ghrelin exerts its effect on the brain by regulating neuronal activity. Ghrelin-induced feeding behaviour is controlled by arcuate nucleus neurons that co-express neuropeptide Y and agouti-related protein (NPY/AgRP neurons). However, the intracellular mechanisms triggered by ghrelin to alter NPY/AgRP neuronal activity are poorly understood. Here we show that ghrelin initiates robust changes in hypothalamic mitochondrial respiration in mice that are dependent on uncoupling protein 2 (UCP2). Activation of this mitochondrial mechanism is critical for ghrelin-induced mitochondrial proliferation and electric activation of NPY/AgRP neurons, for ghrelin-triggered synaptic plasticity of pro-opiomelanocortin-expressing neurons, and for ghrelin-induced food intake. The UCP2-dependent action of ghrelin on NPY/AgRP neurons is driven by a hypothalamic fatty acid oxidation pathway involving AMPK, CPT1 and free radicals that are scavenged by UCP2. These results reveal a signalling modality connecting mitochondria-mediated effects of G-protein-coupled receptors on neuronal function and associated behaviour.
I've also skimmed the paper and would note that the press release seems to sensationalise the story a wee bit. The study is about some complex biochemistry and the idea of carbs being a problem is really only hypothesised in the discussion.