Groton — Courtney Murphy, a 35-year-old Stonington resident, started noticing a while back that her weight was increasing and nothing she could do on her own was making much of a difference.

So she decided to check out a new business called Rob Nevins' Slim Nation that is gearing up for a grand opening at 5:30 p.m. Tuesday. And so far, in only four weeks, she has lost 12 inches on her measurements.

"People at work are noticing it," she said. "Clothes are fitting so much better."

Murphy is one of the early local adherents to a weight-loss strategy originated by Nevins, who founded his original business Living Lean in Wallingford and has since spread out to several other locations. Now, he is planning to take his idea nationwide by franchising Slim Nation out of a 2,000-square-foot headquarters building just established on Long Hill Road.

Nevins' weight-loss program is surprisingly simple, which he said is what makes it so effective. It involves coaches devising meal plans based on the types of foods clients enjoy, and then allowing them to eat a fairly normal breakfast, lunch and dinner, plus two snacks.

One day out of every three, clients are allowed to exceed this diet with extra goodies that would be forbidden under other weight-loss systems.

"It becomes a way of living, not a diet," Nevins said during an interview last week. "It's normal; it's not weird. It's based on foods clients pick — foods you can find in any supermarket."

Kate Careb of Stonington, vice president of operations and national development for Slim Nation, swears by the program. She lost 25 pounds as a Nevins client, and now she and friend Anne-Marie van der Velde of Stonington have opened the new business in Groton, with plans for national expansion, with a smaller store slated to open next month in Stamford and negotiations underway for another in Florida.

"Now it's just how I eat," Careb said. "It's all the food I love. It's not like I ever allow myself to feel hunger."

Nevins said he doesn't emphasize weight loss; he concentrates on eating better. Weight comes off as a natural consequence of eating better, which generally means eating more often and with more thought, rather than requiring costly pre-prepared foods.

He points out that many diets appear to work initially, but are not sustainable. People find it hard to be disciplined over a long period, or can't afford to buy specific foods that are only available through a specialized diet plan at a weight-loss office.

"The goal is to pull off fat," Nevins said. "You lose five pounds of fat, you got a whole different body."

But some weight-loss programs that appear to work initially actually reduce muscle rather than fat, making it harder to keep the weight off because muscle is what helps burn fat, Nevins said. And he added that weight loss involving starvation diets also has bad long-term effects because it slows down the body's metabolism, leading to an inability, again, to burn fat.

Nevins said he gets a lot of his clients from doctor referrals, as well as word of mouth. He believes in such diets as gluten free and GMO free, but he doesn't push them.

Clients can eat hamburgers, lobster rolls, macaroni and cheese – little is off limits, especially on the one day out of three that people can exceed their normal diet.

"I want compliance," he said. "I want this place to be user-friendly. ... This is the last place to come if you want to lose weight fast."

As for exercise, Nevins believes in it but said at most regular workouts can contribute only about 20 percent to weight loss vs. 80 percent attributable to food intake.

"You're never going to outrun your fork," he joked.

And just like with exercise, he said, clients need a rest from their diet. With Nevins' plan allowing a diet break one out of every three days, they can go to a party or eat out with friends occasionally without feeling guilty.

Sometimes learning to lose weight is just a matter of understanding how different foods are metabolized, he said. For instance, he said, it is much easier to keep weight off if you eat a piece of cheese before drinking a glass of wine; the effect is lost if the wine preceeds the cheese.

"I want to speed the metabolism up," he said. "The most effective way to stimulate the metabolism is to ... eat frequently and more often."

To help people along, Slim Nation starts with a personal consultation. From there, individualized meal plans are prepared. If clients aren't able to follow the plan, revisions can be made.

Clients generally check in once every two weeks, and group support sessions are available most nights of the week. Plans are afoot to arrange live feeds with Nevins and bring in celebrity chefs to talk about food preparation and share recipes, with a new mobile app available later this year.

The regular program costs $175 a month for the top-tier plan that includes private coaching and $125 for the basic plan that includes group coaching, though special offers are available for a short period. Clients are required to make at least a three-month commitment.

"In my mind, I've never been on a diet; this is a lifestyle change," Careb said. "It has changed everything for me."

"It's easy to follow," agreed Murphy, the client from Stonington. "It's all laid out for you. ... I just feel better. I have more energy."

And what's better, she said, that dress that didn't fit last spring is looking a bit too large now.

l.howard@theday.com

What: Rob Nevins’ Slim Nation

Where: 428 Long Hill Road, Groton

Who: Anne-Marie van der Velde and Kate Careb

Phone: (860) 440-8633

Website: www.myslimnation.com

Email: katec@myslimnation.com

Hours: M-W-F, 8 a.m.-noon and Tu-Th, 3-7 p.m.