 The word halitosis is derived from the Latin-Greek terms for abnormal or diseased breath, though maybe less of a medical term and more of a marketing term, as it was supposedly coined by the Listerine Company. Halitosis is commonly referred to as bad breath, though medical and dental professionals often use instead of bad breath, the less judgy term, breath odor. As described in the Journal of Breath Research, halitosis has been classified into four types. There's genuine halitosis, either transient or chronic, which is contrasted with pseudo halitosis when someone thinks they have bad breath but it's evidently all in their head. And halitophobia, where they start out with genuine halitosis, but then they treat it and get rid of it but still think they have it. These are rare, though. The vast majority of cases are IOH, which stands for intraoral halitosis. Bad breath arising from inside the mouth, as opposed to lungs or stomach, and not just anywhere in the mouth, but specifically, in most cases, apparently coming off the coating on the tongue. Most people have a tongue coating, a grayish-white deposit on the tongue, which is the main cause of bad breath. And now there are pathological conditions like black, hairy tongue, whose symptoms may include an unattractive appearance of the tongue, which can be caused by certain drugs. But the normal tongue coating is just a thin, slightly moist, whitish substance across the upper surface of the tongue, composed of sloughed tongue cells, bacteria, seepage from our blood supply, and secretions from our gums and post-nasal area, like mucus discharged from our sinuses, dripping onto the back of our tongue. Those with gum disease tend to have four times as much coating in terms of the wet weight scraped off the tongue, due to the migration of white blood cells from periodontal pus pockets onto the tongue's surface. But even in people with perfect dental hygiene, food particles can get trapped between other little bumps and cracks on the tongue and form a thick bacterial biofilm coating. If we eat the right foods, though, our mouth may be self-cleaning. Just the act of chewing and swallowing foods that actually need chewing can cleanse off the tongue, leaving you with just a normal, thin layer of coating. But fast food is engineered to be eaten fast. It's soft, you can just, you know, gulp it down, and consequently, the thickness of the tongue coating might increase and that could contribute to bad breath. But you don't know until you put it to the test. The effect of a chewing-intensive high-fiber diet on oral holotosis, a randomized clinical crossover study in which subjects were examined over a period of two and a half hours after consumption of a high-fiber versus low-fiber meal using an organoleptic assessment of holotosis. Although a few electronic bad breath detectors have appeared on the market, organoleptic scoring is still the gold standard, which is just a fancy name for when dentists or doctors just give your breath a sniff. Here's the ratings they used. No holotosis detected, even up close and personal, or, yeah, bad breath, but only up to about 4 inches away, or out to a foot, or all the way out to more than a yard. We know holotosis is reduced by eating due to the self-cleaning of the mouth while chewing food, and it seems obvious that foods that need to be chewed more intensively have a stronger self-cleaning effect than foods that require less chewing. But whether this is actually the case, I'd never been examined until now. The participants were randomized to a high-fiber, high-chew meal with a whole grain roll with jam and a raw apple, versus a low-fiber, low-chew white bread roll with jelly and a cooked apple. And the result? A significantly lower bad breath score immediately after the high-fiber meal and then two and a half hours later compared to the low-fiber meal. The researchers conclude that a chewing-intensive high-fiber meal led to a greater reduction of holotosis.