In sum, it appears that weight regain is the typical long-term response to dieting, rather than the exception. ... They are motivated to maintain their lost weight, and they have the skills to enact the necessary eating behaviors, as they did so when they lost the weight.

What percentage of dieters regain weight?

Experts think as many as 80 to 95% of dieters gain back the weight they've worked so hard to lose.

Why do I always regain weight so quickly?

Weight gain and fluctuations in weight can happen for a variety of reasons. Many people progressively gain weight as they age or make changes to their lifestyle. However, fast weight gain can be a sign of an underlying health condition, such as a problem with the thyroid, kidneys, or heart.