Well to answer one of your questions, yes, there are genetic limitations when it comes to willpower but in a select few. The brain produces a wide array of chemicals. A lot of people who tend to be obese tend to lack, at least in current studies, usually a defficient thyroid (people with slower metabolisms are said to have less motivation, more impulsive, more angry, etc…), lack of seretonin (controls carbohydrate appetite, helps with sleep, prevents the release of cortisol…basically, makes you feel better about things), and/or dopamine (dopamine is highly associated with willpower as is seretonin but dopamine more importantly. It is also believed to work in an amphetamine-like manner which inhibits appetite, yet increases metabolism. It is resposible for sex drive and most certainly will power. It is however catabolic I believe). Some people have an excess release of cortisol from their adrenal glands (cushing’s disease: so their body’s are very fat and have little muscle definition, no matter how much they exercise…One of my friend’s cats has it and she is a real plump cat even though my friend walks her everyday for at least an hour.)Other factors which may influence obesity are appetite receptors in the brain. Studies at least in rats have shown that some mice have more or less appetite receptors. Who’s to say the same could not be true for humans? Also, obese people have a harder time losing weight than skinnier people, not just because of genetics or environment, but because they have more fat and muscle cells their body is telling them to maintain. Even after rigorous weight-loss from obesity, the body still maintains much of the fat and muscle cells it used to have despite them being smaller in size (hyperplasiac), and the appetite tends to be greater for such individuals than say, someone who might weigh the same, be the same height, and have the same activity level. Other factors which play a role is the hormone (I believe it’s a hormone), leptin. Leptin is released by fat cells. It supposedly lowers appetite and increases metabolism. Mice have been shown to have tendencies of obesity yet ate the same as thin mice due to leptin defficencies despite a high number of fat cells, some all together produced no leptin at all. Leptin is also responsible for an increase in activity level. It is highly analogous to a CNS (centeral nervous system) stimulant like an amphetamine for example. It is also harder for an obese person because they tend to have a larger bone structure. Bigger bones tend to be a bi-product of estrogen which of course is something that will stimulate you to store fat. Basically: lareger bone = more food consumption and perhaps, lowered protein synthesis and better fat conversion (if genetic). Other people have very low insulin resistance and because of that, they might get big fast, but in the long run, too many carbs makes them blow up. This tends to ring quite true for a lot of endomorphs. I will admit, not all of it is genetic, but much of it is overlooked. Our ancestors thousands of years ago did not have the luxury of popping food from the fridge in the microwave…they had to get off their asses and hunt. Lowered metabolism probably equaled a better chance for survival. Today, we live in a totally different environment contrary to what most of our bodies want us to do. So yes, some is very much environment. What can I say, some people can sit on their ass all day and never gain weight, others could run a marathon and work out everyday and they still go through hell to keep the fat off. Life isn’t fair but we learn from its inequities I say.