But how good do the meals from these two diet plans actually taste? Consumer Reports asked its experienced taste testers to sample 65 products from breakfasts and dinners to snacks.
Consumer Reports' Amy Keating said the testers didn't know which products they were trying, and they didn't know they were eating diet-plan foods.
The results: most of the foods weren't all that tasty. Testers found the Nutrisystem meatloaf and tomato sauce had an "old flavor." The Jenny Craig Salisbury Steak was better and had flavorful potatoes and vegetables, but the mushrooms were slightly rubbery.
Neither company's snacks and desserts were much of a treat. Keating said most testers found Jenny Craig's Soft Chocolate Cookie was "dry and crumbly, without much flavor."
And Nutrisystem's nacho crisps didn't have much flavor either and were hard and dry.
In the end, only five of the products Consumer Reports tested scored "very good," and all of them were from Jenny Craig.
"Overall Jenny Craig edged out Nutrisystem with respect to taste, but not by much," said Keating
Still, for some people, like Amy Knox, these plans can work. Knox lost 51 pounds in just over seven months using Jenny Craig meals.
"Coming to a place that everything is measured out for you really made the difference for me," she said.
Consumer Reports says on the downside, you spend weeks eating food that doesn't always taste so terrific.
One of the big advantages of diet-plan food is that it's portion-controlled, which is key to losing weight. But frozen diet meals offer that, too. And while you may have to kiss a few toads before you get your prince, there are many that are tasty and economical.