Epidemiology of pediatric obesity
Rosenbaum, M.
Pediatric Annals 36(2): 89-95
2007
ISSN/ISBN: 0090-4481 PMID: 17330571 Document Number: 607074
The ability to store calories as fat would have helped our ancestors to survive periods of prolonged caloric restriction, and would have enhanced the ability of women to breast feed their offspring and provide greater energy stores to nourish mother and fetus during pregnancy. Thus, it is likely that the human genome is enriched with genes favouring the storage of calories as adipose tissue. In contrast, there would have been little evolutionary pressure to favour genotypes that are defending body thinness prior to the industrial revolution. Our ancestors rarely had the opportunity to consume calories to the point that they experienced significant adiposity-related morbidity, nor did they frequently survive to an age when the cumulative effects of morbidities, such as diabetes and cardiovascular disease, would have a significant effect on their health or reproductive capacity. In an environment that favours the consumption of calorically dense foods and a sedentary lifestyle, any "defense" against further weight gain is stretched to the limit, while opposition to sustaining weight loss remains potent and viable. Thus, we are confronted with a tendency for our own metabolic systems to be "biased" toward further weight gain and biased against attempts to sustain weight loss.