THAT'S THE WHY:Obesity is the result of taking too many calories on board and not burning them off. Right?
Well actually, as with pretty much any biological system, it’s complicated.
Yes, the energy surfeit is the root cause of the excess weight, but there are other factors involved that can affect metabolism and how we handle that “positive energy balance” as it’s referred to in the literature.
One appears to be chronic stress, which is thought to be linked to obesity, and particularly fat storage on the abdomen.
But why could ongoing anxiety about your job or finances, not getting enough sleep or just generally being under pressure and keeping your wheels spinning too much of the time, affect your waistline?
It’s thought to be partly down to the hormones our bodies release to help counter such chronic stresses.
Teasing out the complex hormonal pathways and metabolic effects that underpin this link would itself contribute to one’s stress levels – but the short version is that the hypothalamic-pituitary-adrenal (HPA) axis gets stimulated and results in the hormone cortisol becoming active, which can promote fat accumulation.
Plus, as a 2006 Annals of the New York Academy of Sciences article, Stress, Visceral Obesity, and Metabolic Complications, points out, it may be a vicious circle: “Stress, primarily through hyperactivation of the HPA axis, appears to contribute to the accumulation of fat tissue, and vice versa, obesity itself seems to constitute a chronic stressful state and may cause HPA axis dysfunction.”