She said the secret to combining her career with new motherhood is setting up a sleep schedule for Camden and then working around it. She said Camden began sleeping through the night when he was only 6 weeks old.
"If you establish a routine for your child, then your routine can be more manageable," she said.
Lachey, 32, married to former 98 Degrees frontman Nick Lachey, 39, said she got help from two books, "Healthy Sleep Habits, Happy Child" by Dr. Marc Weissbluth and "On Becoming Baby Wise" by Gary Ezzo and Dr. Robert Bucknam.
Complimented on how much weight she has lost since Camden was born in September, Lachey admitted spending a lot of time watching television, including all six seasons of "Breaking Bad," and eating a lot of cereal.
"I gained I think it was 65 pounds when I was pregnant," she said.
Lachey was on HuffPost to promote "Dads," a new Fox series co-starring Seth Green and Giovanni Ribisi.
2014: The Year in Fashion [PHOTOS]
Morena Baccarin to star on 'Gotham'