Comment by culi

IMHO it's the restaurant. For a variety of reasons but here's just one example of a mechanic:

> Repeatedly heated cooking oils (RCO) can generate varieties of compounds, including polycyclic aromatic hydrocarbons (PAH), some of which have been reported as carcinogenic. RCO is one of the commonly consumed cooking and frying medium. These RCO consumption and inhalation of cooking fumes can pose a serious health hazard.

https://pubmed.ncbi.nlm.nih.gov/28925728/

Nutrition is complicated and rules of thumb can be really useful even if they sometimes over simplify things. One good rule that has had a ton of research interest into it in the past decade or so is ultra-processed foods. Here's a BMJ review

> Greater exposure to ultra-processed food was associated with a higher risk of adverse health outcomes, especially cardiometabolic, common mental disorder, and mortality outcomes. These findings provide a rationale to develop and evaluate the effectiveness of using population based and public health measures to target and reduce dietary exposure to ultra-processed foods for improved human health. They also inform and provide support for urgent mechanistic research.

https://www.bmj.com/content/384/bmj-2023-077310