A doctors’ group has announced what it calls the second heart-related death in a person on the Atkins diet, and is calling for a government investigation into the safety of that and other high-protein, low-carbohydrate weight loss plans.

The Physicians Committee for Responsible Medicine states that a 41-year-old man and a 16-year-old girl died from sudden cardiac arrest while on the Atkins diet. The group wants the U.S. Centers for Disease Control and Prevention to look into adverse effects.

Atkins diet promoters said the group was being anything but responsible in making this announcement.

Agence France-Presse reports that the Atkins center is outraged by the allegations, which the group said could not be definitively linked to the diet. It accused the group of exploiting the tragedy of a few to promote its “vegan” political agenda.