We don't understand all or even most of it. We do understand some of it. I tell people that our current understanding of obesity can be likened to a giant jigsaw puzzle lying in scattered pieces on a table. We have managed to fit a few pieces together here and there, we can make out a tiny fraction of the "big picture" but we still can't tell if it's a photo of the grand canyon or the Eiffel Tower or blue whale.

What I would like to do in the subpages that branch off from here is explore the various theories and hypotheses that are currently being discussed as causes or possible causes of obesity. Let me be clear that these are all theories. We do not know to any reasonable degree of certainty what the cause or causes of obesity actually are and the truth, as usual, is that for most people, there are many causes. But the science is interesting and for those of you who fancy a good mystery, this one is a classic. I hope that I do the various theories some justice.

Genetics

Epigenetics

Obesigens

• Industrial Chemicals
• BPA
• Endocrine disruptors
• pesticides
• ground water contaminants
• Carbohydrate
• glycemic index
• fructose
• fats
• trans-fats
• saturated fats
• omega-6 fats
• Excessively "clean" food (the fat hygiene hypothesis)

Cultural Factors