Unfortunately, Jack in the Box has no menu items that fit our criteria for low carb/keto foods. However, like many places you could order a burger with no bun.
Jack in the Box is an American fast-food restaurant chain founded February 21, 1951, by Robert O. Peterson in San Diego, California, where it is headquartered. The chain has 2,200 locations, primarily serving the West Coast of the United States and selected large urban areas in the eastern portion of the US including Texas. Food items include a variety of hamburger and cheeseburger sandwiches along with selections of internationally themed foods such as tacos and egg rolls.
John Ward has been experimenting with low carbohydrate diets since the early 2000s. He successfully used a low carb diet to lose 50lbs in the past and currently follows a keto diet for a variety of reasons including general health and managing mood levels.