After winning an Academy Award in 2012 for her role in the film The Help, Octavia Spencer decided to tackle a new roll-the one wrapped around her middle. Having tried every diet out there and failed, the full-figured Alabama-native had long given up on depriving herself to get slim. But when she discovered Sensa Weight-Loss System, which lets you eat whatever you want, the 42-year-old foodie opted to bite the bait.

Eight months later, Spencer has lost some 30 pounds and carved out a lovely hourglass shape, which we'll see more of at the premieres of her next films Snowpiercer and Paradise. By next year, when her film with Kevin Costner comes out (they're shooting together this summer), you may not even recognize the svelter Spencer.

Here's how she's resolved how to lose weight while having her cake and eating it too-just not all of it!

SHAPE: How much weight have you lost since you started using Sensa?

OCTAVIA SPENCER (OS): I lost 20 pounds back in February after just five months on the program. I don't weigh myself regularly, so I imagine that I am closer to 30 pounds now. I'm waiting to step back on the scale on my birthday, May 25. I want it to be a bigger number, so I am building up the suspense.

SHAPE: You've got a Biggest Loser moment coming up!

OS: Yes, just me and my mirror. But let me tell you, if it's not a big number, I don't want to beat myself up.

SHAPE: So you've been using Sensa for eight months?

OS: I guess so. I'm not keeping track of time anymore because it's just integrated into my life.

SHAPE: Normally, with diet plans, all you can think about is "How long do I have to do this for?"

OS: That's why I don't diet-I don't like feeling like I'm a prisoner. It's been pretty effortless with Sensa because I am not thinking about how long do I need to do this. Usually when you stop a diet program, you lose control again. But I don't need to stop what I'm doing. I'm eating everything that I like. Sensa just helps me keep it all in check.

SHAPE: For people who aren't familiar with Sensa, can you tell us how it works?

OS: The moment you tell me that I can't have-say, a piece of toast-it's all that I'm gonna crave. With Sensa, I can have toast-with jelly! I just sprinkle Sensa on it. It helps you control the amount that you eat. It doesn't change your diet but rather your portions. I don't have to count carbs or calories. I'd rather not think about the numbers. If I want to eat popcorn at the movies, I know I won't overeat thanks to Sensa. If I'm at a party and I want to have cheese and crackers, I discreetly sprinkle Sensa on the snack. If you can sprinkle, you can lose weight. It's that simple.

SHAPE: What happens when you eat foods with Sensa?

OS: It tells me that, "Hey, I'm full," and then I'm done eating.

SHAPE: Are your girlfriends like, "Can I get some?"

OS: No, I don't share. If they want some, they have to go get it themselves. I have a couple of friends who I know are secretly doing it on their own. It's really easy to be discreet with this. At first, I didn't want to say anything about it. Now if I am at a friend's house and I take out my cute little Sensa carrying case, which looks like a bag for my cell phone, then they know what's up. It's a part of my whole routine.

SHAPE: Is there anything that you won't sprinkle it on because you really want to savor it?

OS: It doesn't change the flavor of food. If it did, I might be a little nervous about that.

SHAPE: So you would sprinkle it on your birthday cake?

OS: Yes, I would! I don't want to eat the whole cake. I just want a couple of bites.

SHAPE: Ultimately Sensa doesn't change what you eat, but just how you eat?

OS: Right. I have tried every diet to lose weight. When you restrict yourself, you're setting yourself up for failure. What impressed me about Sensa is that all I have to do is sprinkle this on my food, and it works. Watching the numbers slowly go down on the scale felt like a natural progression. When you see results, you start to wonder, "What would happen if I had oatmeal instead of sausage for breakfast?" You start to eat better because you feel better. You still enjoy your favorite foods, but you change too.

SHAPE: Do you see yourself using Sensa until you don't need it anymore?

OS: Exactly. I have been heavy for so long, so much of my adult life. Now I found something that is easy to do. Ten days ago, I was in Beijing, and guess what? I had my Sensa with me. I'm going to the Cannes Film Festival in France and Sensa is coming with me. I can take it everywhere in the world with me. I can't do that with any other program without changing the weight restriction of luggage. That is why I had to do something that was conducive to my life.

SHAPE: Do you have a specific weight-loss goal in mind?

OS: I don't have a number on the scale. My thing is my middle. I want my waistline to be proportionate. Right now I still have a little Santa Claus belly. People think that I have this wonderful hourglass figure, but I owe that to designer Tadashi Shoji because he cuts for me really well. Thanks to Sensa, my figure is starting to form, but I have to whittle away a little more. I'm not trying to be thin. I'm just trying to be healthier. When you join the 40s club, it gets harder and harder to lose weight, so you have to find a program that works for you.

SHAPE: Have you seen any immediate health benefits already?

OS: Yes. I hate taking the stairs. It's so easy to hop on the elevator. Well, after losing some weight, I now make myself take the stairs. I can see the difference with my breathing. I can also see the difference with how much effort it takes to walk my three miles and how much time I've cut off of it. These tangible, hard-hitting results are basically how I measure my success.

SHAPE: Walking is your main form of exercise?

OS: At first I worked out with a personal trainer. But I can't take my trainer with me around the world. So I thought, "OK, for the next six-month phase of this, I'm going to do a lot of walking and videos at home." Then I took up Pilates because I like the look of Pilates and yoga bodies. Neither one is easy, which is why the girls look so great. If I get bored of Pilates, I'll take dance classes. And if I get bored again, I'll discover something new. But right now, I do Pilates and walking.

SHAPE: How do you feel right now compared to how you felt before the weight loss?

OS: Oh, I am a different woman. There is something to be said about feeling completely confident in every aspect of your life. That is where I am right now. I know it's because of how I feel about my body and how I feel about my overall health. I am really confident and extremely grateful. Everybody should find something that works for them. I know Sensa works for me because it's very discreet. It's not something that you have to talk about. I am happy to talk about it because I know how hard it is. I know how women tend to beat themselves up because of how difficult it is to lose weight and get healthy. So that is why I am screaming from the top of the roof saying, "Guys, here is something that works for me!"

SHAPE: What I love about it is that you can eat like a "normal person" at dinner. You're not eating a carrot and making everyone else feel awkward.

OS: Exactly! I can get that hamburger or have a slice of cake and know that I'm not going to eat it all with Sensa. If I didn't have Sensa, I would be clearing plates. I'd be clearing the whole birthday cake. Can you bring me a fork and a cake, please?

SHAPE: We wish you the best of luck continuing your weight loss journey. Happy Birthday!

OS: Cross your fingers that the number on the scale on May 25 is a good one!