Hi Nancy! You DEFINITELY want to weight train while you're losing weight! It's not going to prevent excess skin but it
will keep your metabolism revved and build strong, sleek muscles that are going to look awesome as you peel off the fat over them. You might want to check out the 'sticky' thread that we have in the Maintainers Forum about weight loss and excess skin -
http://www.3fatchicks.com/forum/showthread.php?t=36040 - we have several members who have had skin removal surgery after weight loss and posted about their experiences.