The majority of these calorie-restricted diets might lead to nutritional deficits. For example, the keto diet eliminates carbohydrates, a macronutrient that the body requires for energy. Giving up carbohydrates completely might make you feel sluggish, irritable, and even lead to cravings. Giving up one or more food groups might result in tiredness, anaemia, and constipation in extreme situations. For example, A dairy-free diet may cause calcium insufficiency, while a low-carb diet may leave you with insufficient fibre. It’s critical to receive a variety of minerals, including calcium, vitamin D, vitamin B-12, folate, and iron, even on a low-calorie diet.