Maintaining a healthy weight isn’t only about how you look—it also affects your overall health, including your teeth and gums. Research has shown that both being underweight and overweight can increase your risk of gum disease (periodontal disease), an infection that affects the gums, bone, and surrounding tissues that support your teeth.

How Are Weight And Gum Disease Related?

Weight Can Impact Dental Health

Gum disease can cause gums to pull away from teeth, leading to loose or missing teeth. On the other hand, being underweight can increase your risk of osteoporosis, a bone-weakening condition that may lower jawbone density and cause tooth loss.

A study in Scientific Reports found that underweight people had a higher risk of fractures and tooth loss, possibly due to poor nutrition or lack of essential vitamins and amino acids. Similarly, people with obesity were also shown to have fewer teeth, often linked to smoking and poor oral hygiene.

Weight Can Affect The Immune System

Your immune system plays a big role in both weight and gum health. Obesity is known to increase inflammation in the body, which may worsen gum disease. Experts explain that obesity-related inflammation disrupts the immune system, making it easier for bacteria to cause periodontal disease and cavities.

“Obese people are more susceptible to bacteria that cause gum disease,” explains Dr. Salvador Nares, DDS, of the University of Illinois at Chicago. Chronic inflammation is also a key factor in many diseases—heart disease, cancers, and gum disease among them.

The good news? Weight loss can reduce inflammation. Studies show that losing weight—through diet or surgery—lowers C-reactive protein (CRP) and other inflammation markers in the body.

What Is A Healthy Weight?

Healthy weight varies for each person. A key metric used is Body Mass Index (BMI), a simple ratio of weight to height. While BMI isn’t perfect—it doesn’t account for muscle mass, ethnicity, or age—it’s a quick way to estimate general health.

Doctors may also measure waist circumference, waist-to-hip ratio, or waist-to-height ratio to assess fat distribution, which can indicate risks for heart disease and diabetes. Combined with blood tests and physical exams, these measurements help healthcare providers determine your overall health status.

How Nutrition Impacts Oral Health

Weight alone doesn’t tell the full story—nutrition matters just as much.
People who are underweight may lack iron, folate, or vitamin B12, while those with obesity often have vitamin D3, B vitamin, or thiamine deficiencies.

Nutrient Deficiencies And Gum Health

Deficiencies can lead to malnutrition, which may happen due to poor diet, digestion issues, or eating disorders. A lack of nutrients like vitamin C and fiber can increase the risk of bleeding gums and gum disease.

Tooth loss or ill-fitting dentures may also limit your ability to eat nutrient-rich foods, reducing your intake of vitamins A, C, and E, and essential proteins. Poor oral health and poor nutrition often reinforce each other, creating a cycle that affects both your body and mouth.

How To Maintain A Healthy Weight And Prevent Gum Disease

Practice Good Oral Hygiene

Keep your mouth healthy by:

  • Brushing twice daily with fluoride toothpaste

  • Flossing or using an interdental cleaner daily

  • Replacing your toothbrush every 3–4 months

  • Visiting your dentist regularly

Good oral hygiene paired with regular dental checkups prevents most forms of gum disease.

Eat A Balanced, Nutrient-Rich Diet

Follow a balanced eating plan with:

  • Fruits and vegetables

  • Whole grains

  • Lean proteins

  • Low-fat dairy

  • Limited added sugars and saturated fats

Nutrients like vitamins A, B, C, calcium, and zinc can help strengthen gum tissue and prevent periodontal disease. If you’re unsure where to start, speak with a registered dietitian to personalize your plan.

Get Regular Exercise

Aim for:

  • 150 minutes of moderate exercise per week, or

  • 75 minutes of high-intensity activity per week

Exercise helps manage weight and reduces inflammation. Consult your healthcare provider to find the right activity level for your needs.

The Takeaway

Your body and mouth are connected—what affects one affects the other.
Weight changes can influence your immune system, bone health, and inflammation levels, all of which play a role in gum disease risk.
By maintaining a healthy weight, eating nutritious foods, and practicing strong oral hygiene, you can protect your gums and your overall health.