A fad diet is a popular eating plan that promises quick weight loss or health benefits but often lacks scientific support. These diets typically emphasize certain foods or food groups while restricting others, making them appealing for those seeking fast results. However, they may not provide balanced nutrition. Many fad diets can be unsustainable in the long term, leading to yo-yo dieting or nutritional deficiencies. Examples include the Atkins Diet, which focuses on low carbohydrates, and the Cabbage Soup Diet, which promotes eating large quantities of cabbage soup. It's essential to approach such diets with caution and consult a healthcare professional.