Training like an athlete > straving yourself
Many people underestimate the impact of training on body composition. When your a pro runner, training for 3+ hours/day, running, cross training and lifting weights, you are going to get very lean in response to the strong training stimulus. Heavy training allows you to be extremely lean, despite not having the best diet. For example, Michael Phelps consumed 10000 calories/day but was absolutely shredded at 5% body fat. Not all of the food he was eating was "healthy". It definitely wasn't his diet that was making him so lean, it was because of crazy swim workouts.