The alkaline diet is a restrictive eating plan that encourages consuming alkaline-forming foods like fruits and vegetables while severely limiting or avoiding acid-forming foods. The central, unproven theory is that eating in this way can balance your body's pH, which is regulated naturally by your kidneys and lungs. However, the diet's focus on whole foods and reduction of processed items aligns with general healthy eating principles. The following sections detail the categories of foods typically not allowed on the alkaline diet.
Animal Proteins: Meat, Fish, and Eggs
One of the most significant restrictions is on animal-based proteins. During digestion, proteins break down into acidic residues, making them a primary target for elimination. This is a major reason why the alkaline diet is heavily plant-based, with many versions being almost entirely vegetarian or vegan.
Meats and Poultry
Red meats, such as beef and pork, along with poultry like chicken and turkey, are considered highly acid-forming. Adherents to the diet strictly avoid these to minimize their 'acid ash' load on the body. This includes all forms of processed meats as well.
Fish and Seafood
Fish and shellfish are also excluded from the alkaline diet, despite often being promoted in other healthy eating plans. The high protein content classifies them as acid-producing foods in this dietary philosophy.
Eggs
Eggs, particularly the yolks, are considered acidic and are therefore typically prohibited. This restriction, like many others, can create nutritional gaps, requiring careful planning to ensure adequate protein and nutrient intake.
Dairy Products
Dairy is another food group almost entirely absent from the alkaline diet. Products derived from milk are metabolized in a way that is thought to produce an acidic residue.
Milk and Cheese
Conventional milk, including cow's milk, and all forms of cheese are not allowed. These products are high in phosphates, which contribute to their acid-forming properties. Many followers of the diet opt for plant-based alternatives, such as almond or coconut milk.
Yogurt and Ice Cream
Yogurt and ice cream are also off-limits, fitting into the same category as other dairy products. Even natural, unsweetened yogurt would be restricted under these guidelines.
Grains, Legumes, and Nuts
While some nuts and legumes are considered alkaline-forming, many are restricted, especially in more stringent versions of the diet. Grains are almost universally limited.
Grains and Starches
Most grains are deemed acidic and are therefore not allowed, or at least severely limited. This includes staples like:
- Wheat products (white bread, pasta, pastries)
- Oats and other breakfast cereals
- Rice (especially white rice)
- Corn
Legumes
Some specific legumes, like lentils, are considered acid-forming and are therefore restricted. However, some versions of the diet allow certain beans and seeds that are considered alkaline, leading to some confusion and variation.
Processed Foods, Sugar, and Alcohol
Highly processed foods, which often contain added sugars, sodium, and preservatives, are among the most strictly forbidden items on the alkaline diet. This aligns with standard healthy eating advice, though the reasoning is based on pH theory.
Sugars and Sweeteners
Refined sugars, including high-fructose corn syrup, are considered one of the most potent acid-forming ingredients. This applies to candy, baked goods, and sugar-sweetened beverages like soda.
Fried and Processed Items
Chips, crackers, fast food, and canned convenience foods are all off the menu. The combination of saturated fats, sodium, and preservatives in these items places them firmly in the acidic category.
Coffee and Alcohol
Coffee and alcoholic beverages, such as beer and wine, are also not allowed due to their highly acidic nature. This is a common point of restriction across all versions of the alkaline diet.
Comparison: Acidic Foods vs. Alkaline Alternatives
| Food Category | Foods to Avoid (Acidic) | Alkaline Alternatives (Allowed) |
|---|---|---|
| Protein | Red meat, chicken, fish, eggs | Tofu, tempeh, most beans, some nuts |
| Dairy | Milk, cheese, yogurt, ice cream | Plant-based milks (almond, soy), plant-based cheese |
| Grains | Wheat bread, pasta, white rice, oats | Quinoa, some millet, buckwheat |
| Processed | Fast food, chips, sugary snacks | Fresh fruits, vegetables, nuts, seeds |
| Beverages | Coffee, soda, alcohol, energy drinks | Water, herbal tea, green juices, mineral water |
| Fats | Fried foods, unhealthy oils | Avocado, olive oil, nuts, seeds |
Conclusion: Navigating the Restrictions
While a strict interpretation of what foods are not allowed on the alkaline diet requires eliminating numerous common staples like meat, dairy, eggs, and grains, the overall health benefits of focusing on whole foods are well-documented. The key takeaway for anyone considering this dietary approach is that the restrictive nature can lead to nutritional deficiencies if not carefully managed. As with any significant dietary change, it is advisable to consult a healthcare professional to ensure your nutritional needs are met. The diet's strongest advantage may be in its emphasis on eating more fruits and vegetables, rather than its unsupported theory about blood pH.
The alkaline diet: What you need to know - MD Anderson Cancer Center
