Why were they a no-go? When the low-carb craze hit, the humble white potato was slapped with a big red X as it was claimed they are devoid of nutritional value and are super fattening. Why they were wrong: One average-sized baked potato only contains around 160 calories making a baked potato a decidedly low-calorie lunch option! Potatoes contain lots of fibre to help keep you full as well as a variety of vitamins including vitamin B and folate, and are said to help lower blood pressure. Make sure you keep the nutrient rich skin on your potatoes when eating them to get the most out of your potato!