DerbyX DerbyX:
Actually there are genetic factors that play a big part. Cortisol for example. Gherlin is another. Hormones that affect appetite, fat regulation, and metabolism for example. Genetics can play apart in nutrient absorption. A decreased absorption rate means less calories per bite. In addition, many of these hormones are tied to psychological well being or physiological factors. For instance, sleeplessness affects allergies. Lack of sleep affects white blood cells which affect allergies as well as many other things.
Diet is important. A calorie free life isn't the end though. I recall a very sad event from my childhood where the community was shocked by the early death (36) of a man who was a fitness person. Active and healthy. Died of a stroke. My dad quit smoking 3 days after that happened.
Genetics play a part in how difficult it is, but it doesn't stop one from achieving it. The people who bitch that genetics stop them, are just too lazy to do anything about it.
I myself was horribly out of shape, and still am. Woke up one day, said fuck this, and started changing. I lost 15 pounds in 2 months. That was through very little lifting, no cardio, and a proper diet. Now add on actual proper exercise, and it would increase. Sure I'm young which may make it easier, but anyone can do it. I have no patience for people who come up with excuses anymore.