Moreover, the effect of increased weight loading on body weight seems to be robust when comparing with the variable, often small, effects described in randomized controlled trials of exercise and other life style changes [27], [28], [29] as well as of leptin treatment on body weight in most cases of obesity [12], [13], [14], [15], [16]. The gene discussed is LEP; the disease is obesity due to melanocortin 4 receptor deficiency.