Key 1: Start Eating Filling Foods
Feeling bloated isn't the same as feeling full. The first comes from scarfing a whole frozen pizza and a liter of soda. The second comes from eating foods filled with fiber and protein. And the feeling lasts—our bodies process the nutrients slowly, unlike the empty calories of that pie and pop. Atwater made sure he ate foods rich in fiber and protein, and began eating healthier snacks—such as almonds, or Greek yogurt with low-sugar granola. Other ideas: dried fruit, beef jerky, chocolate milk, cheese, or even tuna. (Search: Snacks for weight loss)
Key 2: Nix the Sports Drinks
The carbs in sports drinks provide fuel for exercise; directly afterward, they reload glycogen stores, helping muscles stay energized. "But any other time, they have the nutritional impact of Kool-Aid," says nutrition consultant Michael Roussell, PhD. If you consume sports drinks and empty carbs, and don't exercise often, those carbs provide the excess calories that may lead to weight gain. Just ask Atwater.
Avoid This Common Food Chemical
Key 3: Challenge Yourself
Although Atwater had occasionally exercised before, regular workouts were difficult at first. So he started with basic body-weight exercises, such as pushups, pullups, and squats. Then, to add challenge and variety to his routine, he began to incorporate weights. (Video: Improve your pushup with this simple trick)
"Pushing yourself further safely each time you're in the gym challenges your mind and muscles by never allowing them to adapt and become complacent," says Belly Off! trainer David Jack. If a workout seems too easy, mix it up the next time.
Key 4: Prevent Workout Boredom
Atwater eventually added single-leg, straight-leg deadlifts and spiderman pushups to his regimen. These workouts helped him improve his muscle endurance for another fitness quest: The 2011 Boston Marathon, which he ran as part of the Dana-Farber Marathon Challenge team in support of cancer research.
"I finished the race," he says. "A feat, considering a 5-K—let alone 26.2 miles—was tough when I was at my heaviest."
Find out how to run off 10, 20, 30 pounds or more!