Nightshade sensitivity is a food-intolerance pattern linked to reduced tolerance for specific plants in the Solanaceae family, especially foods such as tomato, eggplant, bell peppers, chili peppers, and potatoes. These plants contain natural defense compounds including glycoalkaloids, steroidal alkaloids, and related nitrogen-containing phytochemicals. The primary potato glycoalkaloids are alpha-solanine and alpha-chaconine, while tomato contains tomatine-related compounds and peppers contain capsaicinoids. These compounds are normal plant metabolites and are not automatically harmful for most people, but sensitive individuals may experience digestive, inflammatory, neurologic, or joint-related discomfort when intake exceeds tolerance. The biological pattern is not the same as a classic IgE food allergy and is better described as an intolerance or sensitivity pattern involving epithelial irritation, immune mediator activity, intestinal permeability, acetylcholine-related signaling, oxidative stress, and inflammatory pathway activation. Glycoalkaloids have been studied for their ability to disrupt cell membranes and inhibit acetylcholinesterase activity at sufficient exposure levels. Digestive studies describe possible effects on intestinal barrier function and inflammatory susceptibility. In practical dietary patterns, response may depend on food type, dose, preparation, storage, ripeness, and individual susceptibility. Green, sprouted, damaged, or improperly stored potatoes can contain higher glycoalkaloid concentrations than properly stored potatoes. A whole food plant-based diet for nightshade sensitivity focuses on removing suspected nightshade triggers while preserving nutrient density from non-nightshade foods. This prevents unnecessary restriction and keeps the dietary pattern centered on fiber, vitamins, minerals, amino acids, antioxidant systems, and gut-supportive carbohydrate patterns. Replacement foods commonly include sweet-potato-orange, butternut-squash, pumpkin, carrot, beetroot, cabbage-green, kale, broccoli, cauliflower, green-peas, cucumber, zucchini, celery, pear, apple, banana, papaya, blueberry, brown-rice-cooked, quinoa-cooked, oats-cooked, navy-beans, chickpeas, lentils-green, pumpkin-seeds-dried, sunflower-seeds-dried, and chia-seeds-whole-dried. These foods provide potassium, magnesium, manganese, vitamin C, vitamin B6, vitamin B9, vitamin E, vitamin K1, fiber, resistant starch, plant protein, and polyphenols without relying on tomato, pepper, eggplant, or potato-based meals. Support is centered on gut barrier stability, steady bowel rhythm, antioxidant defense, mineral adequacy, inflammatory balance, hydration, and avoidance of ultra-processed foods and concentrated nightshade seasonings.