In this article, Russell Berger critiques a Stanford twin study that claimed a vegan diet improves cardiometabolic health compared to an omnivorous diet. While the study received widespread media coverage highlighting reduced LDL cholesterol among vegan participants, Berger argues that the conclusions are overstated and not supported by the data. He raises concerns about potential sponsorship bias, noting that the study’s lead author received payments from the plant-based food company Beyond Meat. Berger also points to methodological weaknesses, including reliance on self-reported dietary recalls and the fact that the vegan group consumed fewer calories and lost weight—factors that could independently explain the drop in LDL cholesterol. More broadly, he argues that LDL itself is an imperfect surrogate marker for cardiovascular health and that the study failed to examine more meaningful measures such as LDL particle subtypes. Because the study was not designed to separate the effects of diet from caloric restriction, Berger concludes that the research cannot establish a causal relationship between vegan diets and improved heart health, despite the confident claims made in media coverage and interviews promoting the study.