According to People magazine ...
After gaining 60 lbs. while pregnant with 19-month-old son Ryder, Kate Hudson lost the weight “pretty fast" by relying on a 1,500-calorie-a-day diet that was high in protein and low in carbs – and doing three-hour daily workouts. But Hudson, 26, still allows herself some indulgences: While filming Skeleton Key in New Orleans, she sampled some local delicacies, including stuffed crab and crawfish.

What is Kate Hudsons Diet?
High Protein low carb eating plan (limited wholegrains, no bread, lots of chicken/fish)
How Does Kate Hudson Workout?
She combines cardiovascular training with weight training.