WEIGHT AND PREDISPOSITION TO OBESITY
A large part of our predisposition to obesity is undoubtedly genetic. After that, our predisposition depends on our interaction with the environment.
We all know that some people, who seem to be inactive, are apparently able to eat whatever they like, in whatever amounts and do not appear to gain weight. Equally, people who have inherited a family history of obesity will spend a lifetime fighting against excessive weight, while appearing to eat very modest amounts.
It was said of Daniel Lambert - the celebrated eighteenth-century 52-stone man - that he '...ate moderately, drank only water, and slept less than most persons'. Despite his 112-inch waistline he '...ate only one meal a day, never snored, never retired before 1 a.m., never slept more than 8 hours and was partial to the female sex'. This apparently non-pathological obesity (although he did die prematurely at 39 years of age) could have been the result of a variety of reasons, but was most likely the result of genetic predisposition.
'Non-exercise activity' might be significant in some of those individuals who appear never to gain weight. Individuals who fidget when sitting will use one-third more energy than if they were totally still. If these individuals stand and fidget, they will use twice as much energy than if they were standing still and 2.5 hours of fidgeting would use up an extra 200 kcal. Such non-exercise activity might influence an individual's total daily energy expenditure.