Not brushing your teeth properly can cause weight gain, dentist says

A dentist has explained how poor oral health could be quietly contributing to weight gain. According to Dr Andrej Bozic, an oral surgeon at Dentum, gum disease and harmful bacteria in the mouth can impact more than just your teeth - they might also be affecting your gut health, metabolism, and even your cravings.

“Poor oral hygiene can create a cascade of problems that affect your entire body, including your metabolism and weight,” he said. Gum disease, or periodontal disease, is a chronic inflammatory condition caused by harmful bacteria that accumulate in the mouth.

“When your gums are infected, the bacteria don’t stay localised - they can enter your bloodstream and spread inflammation throughout the body,” Dr Bozic explained. This chronic inflammation can contribute to insulin resistance and metabolic imbalances, which are both linked to weight gain.

READ MORE: Woman says 'effective' five step routine restored her thinning hair - and it's so simple

READ MORE: Type 2 diabetes: Two plant milks are the 'best' for lowering insulin

“When inflammation becomes systemic, it affects how your body processes glucose, leading to higher blood sugar levels and increased fat storage,” Dr Bozic added. In other words, poor oral health doesn’t just harm your gums - it may also affect your body’s ability to regulate weight.

The harmful bacteria from gum disease can make their way into the digestive system, disrupting the gut microbiome - the complex community of bacteria that play a key role in digestion, immunity, and metabolism. “Oral bacteria can upset the balance of good and bad bacteria in your gut, which may lead to digestive issues and inflammation in the gut itself,” Dr Bozic said. An unhealthy gut microbiome can increase cravings for sugary, high-calorie foods and make it more challenging to feel full after eating, both of which can contribute to overeating.

Along with metabolic issues and cravings, poor oral health can create a domino effect that influences eating habits. “When you have dental pain or sensitive gums, you’re more likely to avoid crunchy, fibrous foods like vegetables and whole grains, which are key for weight management,” Dr Bozic noted.

Instead, people with poor oral health may opt for softer, processed foods that are easier to chew but often high in sugar and calories. Improving oral hygiene can help you manage weight indirectly by supporting a healthier gut and reducing chronic inflammation.

“Brushing, flossing, and regular dental cleanings are the foundation,” Dr Bozic said. “Consider adding anti-inflammatory foods like leafy greens, berries, and omega-3-rich fish to your diet as well - they can help reduce inflammation in both your gums and gut.”