Dr. Steven Gundry's The Plant Paradox posits that lectins in common, nutrient-dense foods cause inflammation, weight gain, and autoimmune issues by damaging the gut lining. The program advises eliminating legumes, grains, and nightshades in favor of a diet rich in leafy greens and healthy fats, though many experts argue this approach is restrictive and lacks strong clinical evidence. Read a critical review of the diet at Healthline .