Credit: Mackenzie Douthit on Twitter

If there's one thing we've learned from hours spent watching MTV's Teen Mom and its sister-friends, Teen Mom 2 and Teen Mom 3, it's that raising a baby is expensive.

Between clothing, gear, diapers and food, raising a bundle of joy can cost thousands of dollars per year — and most teen parents simply can't afford the expense. However, there's an easy way to cut down costs...breastfeeding!

Breastfeeding a baby for its first year is majorly beneficial to its health and immune system, but it also happens to be 100 percent free. Meanwhile, formula costs hundreds of dollars — something many of the Teen Mom stars are painfully aware of, including Mackenzie Douthit.

This glamorous bombshell recently gave birth to her second child, Jaxie, and announced her plans to breastfeed back in October. "Im going to breastfeed until she is one so I never have to buy formula," she tweeted.

So, did Mackenzie follow through with her plan? You betcha! Girlfriend gave birth to Jaxie in February, and her lovely lady lumps are still going strong! "Four months old and still on breast milk..." she wrote on June 9. "GO ME."

Mackenzie isn't the only star from the Teen Mom franchise who thinks "breast is best." Teen Mom 3's Katie Yeager is a huge champion of breastfeeding, and Teen Mom 2's Kailyn Lowry is extremely active in her pro-nursing stance. In other words, Mackenzie is in good company!