No one likes that feeling - I get that! How long it can last can depend on different factors. For example - how many calories did you add during this phase? The more calories you add at a time, the longer it will take your body to adjust. It could be a minimum of 3 weeks or it could be much longer. Each body is different. To do the reverse diet process right is to take it very slowly. Be patient with your body AND with the reverse diet. It can be hard and frustrating and overwhelming and feel like it's going to take forever, but it IS worth it. I promise!
