100lbs is a lot to lose and sometimes that number feels insurmountable but I have found that breaking up my weight loss journey into 4 smaller goals of 25lbs lost keeps me motivated and more focused. You can even go a step further and break 25lbs into bi-weekly 5lbs goals. It makes that big goal feel much smaller and in turn each milestone (5lbs, 25lbs, 50lbs, etc.) is a great reason to celebrate the newer, improved and healthier you! You can also apply this idea to physical activity!
I've been here and done this before...previously I was so focused on one number when I should have taken my time and celebrated all of the smaller accomplishments instead of flying over them like hurdles. I truly believe that small goals lead to big and sustained success.