Diets are eating plans for weight management and improved health, often involving changes in food choices and portion sizes. Fad diets with extreme food restrictions are criticized as temporary and unsustainable. Nutritional deficiencies from restrictive diets can cause health complications. A balanced, nutrient-dense diet including whole foods is recommended, paying attention to macro- and micronutrients. Consulting a nutritionist or doctor before starting a diet, especially with underlying health conditions, is crucial. A healthy diet should be a lifestyle, not temporary.