Starbucks might have plenty of high-calorie Frappuccinos, pastries and cake pops on offer, but a Virginia woman says she was able to eat there every day for two years and lose almost 38 kg (85 pounds).

Christine Hall, 66, has gone from weighing over 90 kg (200) pounds to a trim 52 kg (115 pounds). The law librarian says she was able to do it by skipping over the coffee chain’s treats and sticking with the pre-wrapped sandwiches and food boxes.

“A lot of people look at the top shelf and they see pastries and fattening things, but look down on the second shelf, there are really healthy choices,” she told NBC News.

All of the items list their calorie information clearly on the label. So Hall mixed up her meal choices, kept track of the calories and then watched the pounds melt away.

“Losing weight is hard but I realized I could do it. I found a system that worked for me,” she said.

Hall says sticking to the diet was easy because she was stopping in for coffee every day anyway.

“I have a busy schedule, so it just works for me,” she said. “I know exactly what I’m getting. I can plan my day in advance because I’ve memorized the calories in everything,” she says.

A typical day for Hall includes oatmeal and coffee for breakfast, then a “bistro box” with fruit and cheese for lunch, and a panini for dinner.

As Hall’s weight dropped off, employees at her local Starbucks cheered her on. And now Hall says she’s feeling better than ever.

“I had sleep apnea and I was tired all the time," Hall remembers. "My joints hurt. It hurt to stand up.”

Now, she says, nothing hurts anymore. “I have no medical issues whatsoever. I just feel like a kid again,” she says.

But registered dietician Rebecca Scritchfield of Washington, D.C. warns that Hall may not be able to maintain her weight loss if she ever stops eating at Starbucks. She also worries that her diet could lead to malnutrition.

"When you follow something that restricts certain food groups or that limits you to one particular restaurant, it's very difficult to be healthy and meet your nutrition needs," she told NBC.

Still, Hall is not the first to eat at the same restaurant every day and lose weight.

U.S. man Jared Fogle ate Subway sandwich restaurants every day and parlayed his stunning 111-kg (245-pound) weight loss into a new career as a Subway spokesman. Others have also claimed to have lost weight by eating at McDonald's, skipping over the Big Macs and fries and choosing instead the salads and wraps.

Hall says she is still eating at Starbucks, eating enough calories to maintain her weight.

"I'm so blessed with good health," she said. "I sleep like a baby and I have tons of energy. It's great."