The phrase "diets don't work" means that diets don't work in the long run. If you simply go on a diet and don't permanently change your lifestyle, you will likely gain back the weight. In fact, crash dieting has a dismal long-term success rate of only 5-10%.

The reason crash diets fail is simple: they are often punishing and motivated by negative self-talk. Most people cannot sustain such a negative way of life.

The trick is to focus on the positive.

Find healthy foods you enjoy. Don't force yourself to live on grapefruit, bacon, cabbage soup, or whatever fad diet is sweeping the nation. Instead, use MyFoodDiary to tweak your existing diet and watch portion sizes. Replace unhealthy foods with healthy alternatives, and learn how to cook delicious, healthy meals.

Find exercises you enjoy. If you hate running, don't run. If you're outdoorsy, set a goal of hiking all trails within an hour's drive. If you need more time with friends and family, schedule walking dates or set up a volleyball net in your backyard and host an activity-based party.

When it comes to fitness, there is no one-size-fits-all approach. Experiment with different meals and activities to discover what works for you. Once you've found the right mix, you will discover that healthy living is not a sacrifice, but instead, your life is enriched by it. Most importantly, you will find that you have shifted to a new lifestyle, which means long-term health benefits.

Lori Rice, M.S., is a nutritional scientist and author with a passion for healthy cooking, exercise physiology, and food photography.