Is saggy skin an inevitable byproduct of remarkable weight loss (100+ lbs)? if so, are there any non-surgical ways to prevent this?

Redundant skin: Extreme weight loss can be accompanied by folds of excess skin. Sometimes it is under the neck, sometimes in the lower abdomen, sometimes in the chest, thighs, under the arms. It may depend on a variety of factors including amount weight loss, exercise habits, age, smoking, sun exposure, pattern of fat distribution. Imagine a rubber band stretched out for years, it looses some of its elasticity.