Booze on your breath is hard to hide for several reasons. Alcohol is a diuretic, which dries out your mouth. Without saliva, bad-breath bacteria thrives.
Whether it's tuna, sardines, anchovies, or another sort, canned fish stinks. Once canned, the fish oxidizes, leading to a pungent odor.
Cheese stinks. Some of the best-tasting cheeses stink. Bacteria that break down cheese's lactose, lipids, and proteins create halitosis-causing hydrogen sulfide.
Coffee smells lovely before drinking, but not after. Coffee dries out your mouth, causing bacteria to grow.
Garlic includes two types of sulfur compounds that enter your bloodstream through your stomach and exit your body through your lungs.
Onions are just as potent as garlic because they contain the same sulfur components. You can't go wrong with the help of the Beasties.
Protein-rich foods (meat, eggs, dairy, and nuts—including peanut butter) create an ammonia-like scent when broken down, and fatty acids break down into ketones, which have a metallic or acetone smell.
Peppers can leave a temporary coating of spices on your tongue, and if you can still taste it, others can still smell it.
A tasty tomato sauce can be bad for your breath. Tomato sauce (and juice) can provoke acid reflux, which worsens bad breath.