The most dangerous dieting moment of all isn’t the first time you’re tempted with a piece of chocolate cake.

It’s when you’ve lost, say, 20 pounds when you want to lose 25—and it seems like nothing you can do will get you there. You keep exercising, you stick to your eating plan, but the needle on the scale stays the same.

That’s what’s known as a plateau, and it can cause you to slide back into your bad old habits, according to experts. Says Dr. Nicholas Yephantides, spokesman for the TOPS weight-loss organization, “The plateau can be a real motivation killer.”

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It’s important to be sure, though, that you have hit a real plateau. Are you really still eating and exercising according to your weight-loss plan, or have you slipped a little? Says Dr. Yephantides, “I frequently discover what I call a ‘perceived plateau’…with people who are frustrated by their weight loss.” Keeping a conscientious food diary should tell you whether you’re going over your calorie limit.

If your body really is just being stubborn, it’s probably because it’s adjusting to your new weight and may “think” you’ve lost enough fat already. But if you know that an additional loss of, say, five pounds is a sensible goal, there are some steps you can take to get past the plateau.

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Dr. Yephantides’ suggestions:

*Keep to your same total of weekly calories, but eat more one day and less the next: Sending varying signals to your body can make it react in different ways and get it off that plateau. Also, he says, “Drink water to feel full and avoid dehydration.”