Will losing 5 pounds a week make your skin sag?

Yes if you don't exercise while losing the weight. Join a gym and work-out on those muscles (especially the pecs) which helps the lower back as well. Also weights for to tone up the arms. If you are not male, then 5 lbs. per week is far too much to lose on a weekly basis. The first 4 weeks you could lose 2 lbs - 3 lbs., but after that it's usually 1 - 1 1/2 lbs., if you are doing what a good diet tells you to do. Don't forget, muscle weighs more than fat. Agree with the exercise, but it also depends on your age. As you get older your skin loses its elasticity and doesn't bounce back the way it used to.