In a rather sobering study, scientists have demonstrated that a high-fat diet¹ has the potential to drastically alter the architecture of the brain, resulting in poor circulation within the brain, down-regulated metabolism, and outright brain damage in areas of the brain central to appetite regulation. The implications of the study are that once a person starts eating too much and continues to do so for a period of time they are inducing actual brain damage that will be difficult to reverse — in turn locking in a poor state of metabolic health.

Many people who are overweight can simply cut back on calories, exercise more, and the weight comes off. Such people have pushed their metabolism into a state of stress but have not yet crossed a more serious inflammatory line wherein the ability to bounce back by doing the right things is compromised.

"It appears that this base wiring of the brain is a determinant of one's vulnerability to develop obesity," said Tamas Horvath, who is also co-director of the Yale Program in Integrative Cell Signaling and Neurobiology of Metabolism. "Those who are vulnerable to diet-induced obesity also develop a brain inflammation, while those who are resistant, do not," he said. "This emerging inflammatory response in the brain may also explain why those who once developed obesity have a harder time losing weight."

The researchers studied in great detail the brains of two types of mice, those predisposed to obesity and a strain that was resistant to obesity. Both strains were fed a high-fat diet. In the strain that gained weight, a concurrent “slow burning forest fire” took place in their brains altering the integrity of the blood-brain barrier, compromising the flow of blood to the hypothalamus gland that regulated appetite and metabolism, and actually causing extensive damage to the plasticity of nerve cells that make up key regions of the hypothalamus gland.

It is easy to predict that most people who struggle to lose weight (even those who eat well and exercise) are haunted by unmanageable cravings to eat. Those individuals whose state of cognitive fitness is not what it used to be are suffering from some degree of this type of brain damage. Such changes are not impossible to fix, but they are far from easy to fix.

Aerobic exercise combined with nutrition that helps restore brain plasticity is the path out of this mess. However, the path is likely to be a bumpy ride until brain function is improved, as cravings and sluggish metabolism may cause frustration. Even a person doing everything right may take months to get themselves out of the woods in terms of actually helping to restore brain circulation and plasticity. This means a person may need a king-size supply of willpower to stay on a healthy program until actual brain health has been improved.