HACKETTSTOWN, N.J. - Snickers and Twix are going on a diet. By the end of 2013, Mars Inc. said it would no longer sell chocolate products that contain more than 250 calories, Reuters reports.

The company said it wants its products to have better nutritional value and to sell the candy in a more responsible way, said Marlene Machut, Mars spokeswoman. The new limit on calories effectively nixes the king-size category for the company. The Snickers king-size bar packs 540 calories.

The move is part of an overall change in how the company does business. Five years ago, Mars stopped purchasing ad time or space if more than a fourth of the audience could be comprised of children under 12. The company also has said that by 2015, it will slash salt in all its products by 25%.

The company plan to halt shipments of chocolate products packing more than 250 calories per portion by the end of next year is part of a "broad-based commitment to health and nutrition," said Machut.

The changes didn??t stop Mars from unveiling new chocolate products for Christmas 2011.