Quite a few variables can lead to obesity: overeating, lack of exercise, blood sugar and metabolic problems caused by poor diet, etc. But genetics has long been seen to play a central role. A recent study suggests that at least one of obesity's inherited determinants has more to do with the way our brains work than the way we process the food we eat or the sedentary lifestyles we choose to lead.

 

The study is not the first of its kind: in the last few years of clinical research, obese individuals have been found to share seemingly unrelated genetic variations that affect different aspects of the body mass equation. One recently discovered gene, for example, controls the power of appetite and an individual's ability to satisfy it. Another affects insulin rates and the internal production of fatty acids and cholesterol. The precise effects of this newest gene have yet to be detailed in clinical reports, but the fact that all three relate to the process of encoding brain proteins implies that, for many individuals, obesity begins with a faulty communication network in the central nervous system.

 

Perhaps most interestingly, this genetic variant, named NRXN3 and carried by 1 in 5 adults, has previously been linked to substance abuse and addiction. It may well be that a predisposition toward obesity, at least in subjects carrying this gene, is spurred by the same variation that facilitates compulsive behaviors related to the release of pleasure hormones in the central nervous system. Only further research will clarify the relationship between the two, but researchers can already infer a link - no such correlation can be completely coincidental.

 

So do behaviors encouraged by this gene lead to obesity, or does the gene alter our internal chemistry in a way that significantly increases the likelihood of excessive body mass? We know that the children of obese parents are considerably more likely to be obese themselves and that genetics, along with behavioral traits reinforced in the home, play a large role in that equation. But the fact that this study involved the third independent genetic variant linked to obesity in the last three years hints at the fact that the condition is far more complicated than it may seem - and that a history of overweight family members does not necessarily guarantee poor health. Individuals with weight problems must be reminded of that fact. Reports like this one should be used to re-emphasize the crucial importance of dietary moderation and regular exercise in keeping the body at its optimal level.