7. The “Only One Food” Diet
Some fad diets encourage eating only one food for an extended period — like bananas, eggs, or potatoes. While simple in concept, this approach deprives the body of the variety of nutrients it needs to function. Over time, this can cause vitamin and mineral deficiencies, digestive issues, and metabolic slowdown. Variety in food isn’t just enjoyable — it’s essential for balanced nutrition and long-term health.