The TV star and her film director husband Alejandro Monteverde welcomed baby Marcelo in October (11) - just two weeks before Landry was due to start work on her partner's latest drama Little Boy.
She gained 45 pounds (20 kilograms) during her pregnancy and she enlisted the help of a special meal delivery service to help her shape up.
Landry tells Usmagazine.com, ""It was pressure. I don't get it delivered on the weekends. It has helped me be aware of portion control and to include a balance of of protein, vegetables and complex carbs in my meals.""
The star lost 12 pounds (five kilograms) in two months as a result of the diet - and she is pleased with her slim new figure: ""It was a thrilling moment for me to fit into a size four dress at the Oscars.""