hey, im 5'1 and 142 lbs, I want to lose about 15 lbs. depending on how your body is proportioned being 105 lbs probably isnt a great goal, you might just end up looking like a stick. Its up to you I guess. The best advice I can give you is eat right and exercise. I used to be down to 128 from 160 but I gained some of it back, its really helpfull to count your calories and keep track of what you eat. anyways I hope some of this helped.