Forget the gym or five-a-side soccer, running, spinning, zumba and squash. Walking officially beats them all, hands (or rather feet) down. Regular walking is the best thing you can do to achieve and maintain a healthy weight, according to a study from the London School of Economics.It concluded that the brisk constitutional is a better deterrent against obesity than any other form of exercise.Men and women who walk briskly for more than 30 minutes a day were found to have a lower body mass index and smaller waists than everyone else involved in the study."Given the obesity epidemic, and the fact a large proportion of people today are inactive, recommending that people walk more is a cheap and easy policy option," said Dr Grace Lordon, who led the research. ..