Very few people eat whole grain bread and probably 95%+ of bread sold is not whole grain but industrially produced. The problem is not bread nor carbs. The problem is refined/processed carbs, anything coming out of a factory, really. And that is, again, probably the majority of food, and all convenience food, consumed today. That is the problem of our obesity and health epidemic. It’s simple and makes intuitive sense. Highly processed carbs spike blood sugar levels and lead to insulin resistance, obesity, and ultimately diabetes. Dr. Jason Fung writes about this on Medium as well as in his book that everyone should read: The Obesity Code.