Kirstie Alley Maintains Her 50-Lb. Weight Loss By Avoiding 3 Triggers: Cookies, Linguini and Cheese

For Kirstie Alley, the holidays used to be synonymous with overindulging — but this year she didn't fall back into old habits.

"I'm much more disciplined," the Scream Queens star, 66, tells PEOPLE. "I love sugar cookies that are frosted with Santa's faces and trees, so I didn't order any and I didn't have any. My friends were dismayed because I usually give them out as gifts."

She also avoided her two other trigger foods: linguini with clams, and cheese.

"I discovered triple cream Brie cheese this year and I discovered how good that was, so I didn't have that on hand!" says Alley.

The actress lost 50 lbs. with Jenny Craig and has kept off the weight for the past two years.

"I'm on maintenance, so I have one Jenny Craig meal a day and then I'm on my own, but I also have my Jenny Craig consultant," says Alley of how she stays on track. "So if I feel like I'm going awry, I just call her and she gives me some tips and a pep talk."

WATCH: Kirstie Alley Reveals Her Secrets to Keeping Her Weight Off

When she wants to indulge, Alley just makes sure she keeps track of how much she is eating.

"I can have anything I want, I'm just counting the calories," she says. "I know how many calories 6 oz. of tenderloin is. I know that pasta is 200 calories in a cup. So as long as I keep steady that way, and count it up, it's easy to count because I know how many calories those foods that I really love are."

Another way she stays satisfied is by "volumizing" her meals.

"Let's say I have a cup of chili and it's 200 calories, and then I pour it over a big chopped salad — it's still 200 calories basically, but you feel like you're getting a lot more volume," she explains.

In addition to sticking to a healthy diet, Alley makes sure she is active three times a week.

"I started becoming a lot more physical," she says. "It depends on the weather and where I am but I have different workouts I'll do. If I'm in Florida or Kansas where it's flat, I'll get on my bike and ride to my friends' houses. If I'm in a place that's cold, I don't like gyms but I'll go to dance classes. I also like yoga. I try to do that three times a week — pick one of those and do that."