First of all, if your wife graduated from med school, she should have taken the Hippocratic oath. An oath written by the guy considered the father of western medicine.
You know what he had to say about diet?
“Let food be thy medicine and medicine be thy food”
He also said something along the lines of "if you don't know diet you can't call yourself a doctor" but I can't find the exact quote.
>If you think diet and exercise are the only--or even the most effective--means of lowering morbidity for chd (which is what OP is worried about) you'd also be wrong.
Actually, you'd be wrong. Consider a clinical study carried out by the inventor of bypass surgery and another doctor, in the best heart hospital in the world considered by US News & World Report.
The study had very sick heart disease patients, who were told they had a year to live by their cardiologists, change their diet. 23 opted in for the study but only 18 chose to continue with the diet after a couple months. Those 18 patients are still alive today 20 years later, and several had an angioplasty done giving photographic proof their plaque buildup had cleared out. The ones who dropped out died shorty after.
The 18 never had a heart attack after they changed their diets, while before they did they had a combined 49 coronary events (that's ~3 heart related emergencies per person average).