system
Given the following post, respond as if you're commenting on Reddit:
human
Does toasting a loaf of bread alter the nutrition levels?
gpt
Food technologist here just finished with university. 

The short answer is more or less no, the nutrients will not change significantly. You'll get somewhat less water content, but that's not really a nutrient in a technical sense.

The long answer involves a short trip into the delicious realm of food chemistry.

Why is toast so tasty and awesome compared to boring sliced bread? Well, amino acids (aka protein building blocks) will react with reducing sugars (sugars with an aldehyde group) to produce all sorts of yummy flavour compounds. This is called the Maillard reaction, which occurs at pretty much any temperature for many foods, but its most obvious above 150 degrees Celsius or so. These compounds tend to have a brown colour due to their structure.

The flavours produced are highly dependent on the components available. That's why the brown stuff on toast tastes different to the brown stuff on your steak.

In bread, the gluten (protein) and starch (glucose, i.e. the sugar) are degraded. But the quantity that's decayed is very small relative to your whole bread slice.

Nutritional fortifications in bread (commonly folic acid, iodine) are pretty heat stable, so that's not going to change much either.

Finally, a possible carcinogen known as acrylamide may form in starch-rich foods when exposed to high temperatures. However, there has never been any cases directly linking the chemical with cancer in humans. If you're worried, don't be. The chances of you dying from this are so low there's probably tonnes of other stuff to worry about in your life instead.