The second week of a weight loss diet may be discouraging if you expect to lose as much weight as you did in the first week. It’s not that your diet has stopped working, it’s because you drop excess fluid in the first week or so, which can lead to unrealistic expectations for the rest of your diet. The good part is that after that initial drop, what you’re losing is body fat -- and that’s your goal.
It's Water, Not Fat
When you first start a diet and reduce your calories, your body reacts by using up the glycogen stored in your muscles and liver. Under normal circumstances, glycogen is your protection against a dramatic drop in blood sugar if you have to go hungry for a while. Glycogen retains water, however. When you burn up the glycogen, the water must be excreted, leading to a dramatic but temporary change in the scale. Set realistic weight loss goals, such as one to two pounds a week, to prevent yourself from getting discouraged after that first week when the pounds seemed to melt away.