It’s possible to experience bad breath as a result of fasting. This happens for a few possible reasons. One, your body produces less saliva when you’re not eating. That saliva helps break down bacteria in your mouth. There’s less saliva available to do that when you’re fasting. The smell can also come from bacteria in your digestive fluids in your stomach. There are also toxins leaving your body while you fast that can contribute to the problem. Keep mouthwash handy and floss more than you normally would.
You may also develop a white film on your tongue. Use a tongue scraper or a toothbrush to clean that off. Another big side effect is headaches if you’re not
having any caffeine on your fast. Sometimes, people forget to drink water and they get dehydrated. You could feel symptoms of low blood sugar because you’re not consuming sugar and your glucose is down.
Another side effect is extreme emotions. Fasting doesn’t just rid your body of toxins; it can bring up repressed emotions you’ve been stuffing down. You can no longer hide behind the food and those emotions rise to the surface. You may feel more emotional, “hangry,” sad, or want to cry. All of these are natural and the best thing to do is pray about it, go for a long walk, or take a bath instead of running to food.