Fad diets gain popularity because they let you shed pounds quickly, but health professionals warn they often come with side effects, such as fatigue, nausea, headaches, constipation and dehydration.
One additional side effect that doesn’t get as much attention, though, is this: They can cause bad breath.
“Dehydration is the key symptom related to fad diets that can result in halitosis,” says Dr. Harold Katz, a dentist and bacteriologist.
“When you’re dehydrated, your body doesn’t produce as much saliva. When you have less saliva, bacteria growth increases and causes bad breath.”
Katz suggests a few things worth knowing about fad diets and their effect on your breath:
- Fasting. When you fast – or follow a similar fad diet that focuses on consuming a single food or beverage – you’re more likely to become dehydrated, Katz says. “If you’re determined to continue fasting, just make sure you’re still drinking enough water to stay hydrated every day,” he says. “This will not only contribute to fresh breath, but will also contribute to your overall wellness.”
- Ketosis. Ketosis is a low-carbohydrate, high-protein diet that promises quick weight loss if you eat less than 20 grams of carbs in a single day, according to Environmental Nutrition. “It’s true that you can lose weight quickly through ketosis – which is the state your body going into when it doesn’t have enough carbs to feed off of – but you’re not improving your health,” Katz says. “Plus, halitosis can occur as a result of the chemicals released in the body to burn fat.”
- Protein shakes. Some people attempt to lose weight by replacing meals with protein shakes. The Mayo Clinic reports that indeed can help reduce calories, which can lead to weight loss. But if you replace too many regular meals with the shake, you end up missing on the nutritional benefits of whole foods. “That’s not all,” Katz says. “Protein and dairy can cause your breath to smell. You should brush your teeth and use an oral rinse right after you drink a protein shake, or at the very least drink some water afterward to rinse out your mouth.”
Instead of relying on a fad diet to lose excess pounds, Katz says, focus on changing your lifestyle habits as a whole.
“If you exercise regularly and follow a well-balanced diet that’s loaded with nutrients from fruits, vegetables, lean meats and whole grains, you can give your body the fuel it needs to thrive and maintain a healthy weight,” he says. “And your breath won’t be as likely to go rancid.”