Jennifer Widerstrom knows a thing or two about weight loss. On NBC's The Biggest Loser, she has a perfect winning average after coaching two winners to the podium (including last season's Roberto Hernandez). Widerstrom's speciality? Helping her clients create a tailored plan that works for them. We asked the trainer, 33, for her best tips on slimming down-and staying that way.

I often see a lot of spirit in the beginning. But people don't yet have a lot of the tools in place to keep it going. Oftentimes, instead of practicing success, they practice quitting-because they're taking on so much that they can't keep up. Then comes the [thought], I'm failing, I knew it was stupid to try. My advice is to layer your responsibilities so that you don't take on too much too fast. Pick something during week one, and replicate it every day to see how it makes you feel. [Consider] how it changes your workouts, how you look, how it affects your energy. Then during week two, add something else. It could be as simple as tracking your water, or putting a bar in your purse to keep from unhealthy snacking. It's more affective in the long run when you layer in the responsibility.

Give yourself permission to be human. We're all going to have missteps. But know that you can find your footing again, and learn from why you fell off the wagon. When I overeat, instead of hating myself for it, or completely giving in for the week, I sit and I think, What led up to that? I start to put the pieces of the puzzle together and figure out how I can change things next time. Once you identify what these reactions are, you can see them coming and navigate around them.