"I also recommend prioritizing sleep," Jillian said. Sleep and weight gain are closely linked since a lack of sleep will raise cortisol levels (your stress hormone), as well as grehlin (the hunger hormone), and increase cravings, which will prompt you to eat more.
A lack of sleep will also make you too tired to get up for that early morning workout or have the energy to push hard if you do make it to the gym. Plus, a lack of sleep makes you want to eat more and is more likely to give into you junk food cravings. Jillian said to aim to get between seven and nine hours nightly, or whatever you feel your body needs.