By Stephanie Stahl

By Stephanie Stahl

PHILADELPHIA (CBS) — The one thing you do at night that could derail your diet, there’s new research on the sleep connection.

Melinda Farina says she was doing everything she could to lose weight, but the scale wouldn’t budge.  “I’m eating perfectly, I’m working out but I’m not losing this weight. I had no idea what was going on,” Melinda explained. She was so  worried she saw doctors and had bloodwork. Finally, her nutritionist asked about sleep.   Melinda says,  “I was going to bed at like 2am and waking up at six for meetings. I was kind of like in zombie mode.”

Doctors have known some people pack on the pounds when they don’t get enough rest. Now we know why. New research shows that sleep deprivation impacts the production of two hormones that control hunger: leptin and ghrelin. Dr. Steven Feinsilver a sleep expert says, “When you’re sleep deprived for pretty much any reason, both of those hormones change in a direction that should make your appetite go up. So you really get hungrier.”

Another study showed that people who are sleep deprived will eat an extra 300 calories a day. It might not sound like a lot, but it adds up over time. Nutritionist Robin Kaiden says, “When you’re sleep deprived, you tend to make bad decisions, or you don’t think clearly so you kind of grab what’s easy, what’s close. You’re too tired to think of something healthy, you’re too tired to cook.”

Once Melinda started getting a regular eight hours of sleep a night, she says the pounds melted away. Melinda said, “Immediately in that first week, my clothes started loosening up, and the inches started coming off. My whole quality of life has changed, I feel so much better, I’m a lot happier. You absolutely need to get your Zs!”

Sleep needs vary, but experts say most people need between seven and nine hours a night.

Stephanie Stahl