WOMEN know that it is easy to put on excess weight when they are pregnant, partly because they can use the excuse that they are 'eating for two' to over-indulge. Now their beliefs have been supported by research. A study of 2,788 women in Alabama, reported in the Journal of the American Medical Association, showed that women who had at least one child put on between 4lbs and 7lbs over a five-year period, compared with women who remained childless. Surprisingly, they did not put on any more weight in subsequent pregnancies. The authors express concern that this weight gain could make these women more likely to develop obesity later in life.