What does a white diet do?

January 10, 2026 •

4 min read

The term 'white diet' refers to a temporary dietary modification, most commonly prescribed after a teeth whitening procedure to minimize staining. However, it is also used in a medical context for bowel preparation before certain procedures like a colonoscopy.

Quick Summary

A white diet restricts pigmented foods to maintain dental whitening results or limits fiber for medical prep. It is a short-term, specialized eating plan tailored to a specific purpose.

Key Points

Dental Whitening Aftercare: A white diet prevents newly whitened, porous teeth from staining by avoiding pigmented foods and drinks for a short period.
Medical Procedure Prep: In a medical context, a white diet is a low-residue, low-fiber plan used to prepare the bowel for procedures like a colonoscopy.
Duration Varies: The duration of a white diet depends on its purpose, typically 48-72 hours after teeth whitening but 1-3 days for colonoscopy prep.
Distinction from Healthy White Foods: The restrictive white diet differs from a nutritionally beneficial diet that incorporates healthy white vegetables, which offer nutrients like potassium and magnesium.
Focuses on Restriction: The diet focuses on consuming bland, non-pigmented, or low-fiber foods and drinks like chicken, rice, and plain yogurt, while excluding things like coffee, red wine, and berries.
Purpose-Driven: The diet's purpose is not weight loss but to achieve a specific cosmetic or medical objective, and it should only be followed temporarily under professional guidance.

The purpose of a white diet is not singular but depends entirely on the context in which it's being used. While most people associate it with dental procedures, a similar, low-fiber version is critical for medical diagnoses. Understanding the differences is key to following the right dietary plan for your needs.

The White Diet for Dental Procedures

Following a white diet is essential after a professional teeth whitening procedure. When teeth are whitened, their pores are temporarily opened, making the enamel more susceptible to staining. Adhering to a temporary diet of non-pigmented foods protects your investment and helps secure a long-lasting, bright result.

How Teeth Whitening Affects Your Enamel

Professional teeth whitening procedures use bleaching agents, like hydrogen peroxide, to penetrate the outer layer of enamel and break down stains. This process can leave teeth slightly porous and sensitive for up to 48 to 72 hours, making them highly vulnerable to new staining from dark or colorful foods and beverages.

Foods to Eat and Avoid After Teeth Whitening

Foods to Eat:
- Proteins: Skinless chicken breast, turkey, white fish, tofu, egg whites.
- Dairy: Plain yogurt, cottage cheese, mozzarella, white cheese.
- Carbohydrates: White rice, white bread (no crusts), plain pasta, oatmeal.
- Fruits & Vegetables: Bananas, peeled apples and pears, potatoes (peeled), cauliflower.
Foods and Drinks to Avoid:
- Dark Beverages: Coffee, black tea, red wine, cola, dark juices.
- Highly Pigmented Foods: Berries, tomato sauce, soy sauce, balsamic vinegar, curry.
- Sweets: Chocolate, artificially colored candies, ice cream.
- Acidic Foods: Citrus fruits like oranges and lemons, pickled foods.

The White Diet for Medical Procedures

A separate version of the white diet, often called a low-residue diet, is prescribed by doctors to prepare for medical procedures like a colonoscopy. The goal is to clear the bowel of all solid waste, ensuring a clear and unobstructed view for the doctor. The diet focuses on easily digestible, low-fiber foods, which often happen to be white or pale in color.

Preparing for a Colonoscopy

For a colonoscopy, a patient must follow a strict, low-fiber diet for several days before the procedure. This differs significantly from the dental white diet by focusing on fiber content rather than color alone, though the permitted food lists overlap. Colorful but high-fiber white foods, like cauliflower and mushrooms, may be excluded depending on the specific instructions.

Managing Digestive Issues

In some cases, a doctor might recommend a temporary, low-residue version of the white diet for patients experiencing acute digestive distress, such as diarrhea. The bland, low-fiber nature of the foods can help settle the stomach and intestines while still providing some nutrition.

The Broader Context: The Nutritional Value of White Foods

Beyond restrictive, temporary white diets, many naturally white foods offer significant nutritional benefits. These are distinct from the processed white foods (like white flour and sugar) that are often associated with less healthy eating. Research has highlighted the value of foods in the white vegetable group.

Nutrient-Rich White Produce

Garlic and Onions: Contain allicin, a compound with anti-inflammatory and antioxidant properties.
Cauliflower and Turnips: Good sources of fiber, folate, and vitamin C.
Potatoes: Rich in potassium, magnesium, and dietary fiber, especially when consumed with the skin on.
Mushrooms: Contain B vitamins, potassium, and antioxidants. For more information, you can explore studies detailing the nutritional content of white vegetables from institutions like the National Institutes of Health.

Comparison of White Diets: Dental vs. Medical


Feature	Dental White Diet	Medical White Diet
Primary Purpose	Prevent teeth staining after cosmetic whitening procedure.	Ensure clear bowel for medical procedures like colonoscopy.
Duration	Typically 48-72 hours, though sometimes up to 14 days for best results.	1-3 days leading up to the procedure.
Main Restriction	Avoids chromogens (staining agents) and acidic foods.	Focuses on low-residue, low-fiber foods to clear the bowel.
Permitted Foods	White and light-colored foods and liquids (e.g., chicken, rice, yogurt, water).	Low-fiber, easy-to-digest foods (e.g., plain pasta, white bread, low-fiber white veg).
Rationale	Teeth are porous after whitening and absorb pigments more easily.	Solid waste and fiber compromise procedure results.

Conclusion: When to Consider a White Diet

In summary, the specific purpose and constraints of a white diet are defined by whether it's for dental aftercare or a medical preparation. For teeth whitening, the goal is to temporarily avoid staining agents and acidic foods until your enamel has recovered. For a colonoscopy or digestive issues, it is a short-term, low-fiber plan to clear the gastrointestinal tract. While a temporary white diet is restrictive by nature, it serves a critical function for both cosmetic and health-related outcomes. It is important to remember that these are not long-term nutritional strategies but highly targeted interventions for a specific, limited duration. When considering any significant dietary change, it is always best to consult with a medical or dental professional to ensure it is appropriate for your individual health circumstances and goals.

Frequently Asked Questions

The duration depends on the reason. For teeth whitening, it's typically 48 to 72 hours, but some dentists suggest up to 14 days. For medical procedures like a colonoscopy, it's usually 1 to 3 days before the test.

No, you should avoid coffee for at least 48 to 72 hours after teeth whitening. Coffee contains tannins that can easily stain newly porous teeth.

If you accidentally consume a staining food or drink, rinse your mouth with water immediately and brush gently with a non-abrasive toothpaste. Try to stick to the allowed foods for the remainder of the diet period.

No, a white diet is also used for medical purposes, specifically as a low-residue diet for bowel preparation before procedures like a colonoscopy.

For dental purposes, you can eat peeled potatoes, cauliflower, or white onions. For medical low-residue purposes, only peeled potatoes are typically permitted, while high-fiber vegetables are restricted.

Yes, white or light-colored cheeses like mozzarella, cottage cheese, and plain cream cheese are generally permitted on a dental white diet. Avoid highly processed or artificially colored cheeses.

Yes, bananas are a safe and common option for a white diet, whether for dental care or digestive issues. They are low in acidity and have minimal staining potential.