I can see how Mamas might begin to lose weight once your kid enters toddlerhood. Aside from chasing your kid around during waking hours, you also have to be a sneaky eater or else he will want your snack. If it's a snack that I don't want Henry to have (choking hazard snacks, etc.), I have to just shove it in my mouth real quick-like behind a door and then act casual. Eating on the go.
On the contrary, I can see how Mamas might begin to gain weight once your kid enters toddler hood and is more than willing to share his grilled cheese sandwiches and nuggets and graham crackers with you. Yum! I love kid food.
Of course, I am pretty darn pregnant and definitely in the latter category.