Potato is the name for a staple food crop that originated in what is now Latin America. Potato tubers grow underground. The green parts of the potato plant are poisonous, also potato sprouts are poisonous so if you eat sprouting potatoes cut the sprouts off. Potatoes are healthy or unhealthy depending on what you eat with them. If you are eating out baked or boiled potatoes are healthier than chips.
Eaten by themselves potato tubers are healthy in moderation but bland. Eaten with other foods potatoes taste of what’s with them and can taste great. Potatoes are usually eaten hot directly after they have been cooked but you can also let them cool and use them as part of a salad. Boiled potatoes are healthy provided what is eaten with them is healthy. Boiled potatoes can be eaten as a side but some of the goodness leaks into the cooking water and is lost if you throw the cooking water away. Potatoes can be included in soups or stews when they take on the flavour of what is cooked with them and can improve the dish. Potatoes cooked in soups and stews are best as you drink the cooking water and nothing good is thrown away.
Baked potatoes are also healthy when eaten with healthy foods and best eaten with the skin.  Baked potatoes make it harder for the body to regulate blood sugar, therefore if you are diabetic or if your doctor has advised you to watch your blood sugar take care and follow medical advice. Boiled potatoes and mashed don't effect blood sugar the same way.  What should you do? This is recent research and the food scientists will probably understand its implications better in ten years. If you really love baked potatoes they are good for you in many ways. A small baked potato with a healthy filling and healthy side dish is probably better than a large one. If you like boiled potatoes and stewed potatoes as much as you like baked potatoes boiled potatoes are easier to prepare and don't affect blood sugar the way baked potatoes do. Limiting sugar, honey other sweet things like cakes and biscuits is much more important than limiting potatoes.
Oven baked chips (Chips is UK English, they're crisps or French fries in US English) can be made with far less fat than is usual for chips, see below and can be healthier. You can always bake a potato or chips/crisps when you've got an oven on for something else.
Potatoes that can be healthy
Many of us really like fried potatoes and don't want to stop eating them? Well hardly any people have the will power to avoid those tasty, unhealthy foods all the time. If potatoes are shallow fried or oven baked  and little fat is used they are probably less unhealthy than standard deep fried potatoes and may even be healthy in moderation. There's a bit of uncertainty over some unpleasant chemicals that form when potatoes are cooked at high temperature.  Potatoes can be cooked simply with just salt and pepper, not too much salt. Alternatively spices can be used that the person who will eat the potatoes specially likes.
Potatoes can be parboilled and later fried with just over a tablespoon of Oil to a quarter kilo of potatoes.
One can put a lot of effort into fried potatoes, cut them up, soak them in Water, later fry them in vegetable oil.
A simpler alternative is to cut potatoes into slices about a centimetre to half an inch thick just before you cook them and shallow fry them in oil turning them at least once.
How healthy are the above recipes? That depends on how much oil is used (measuring out a small amount of oil is best), how often those potatoes are eaten and how much fat there is generally in the diet of the person eating them.
Fried potatoes usually have too much fat, crisps usually have too much salt and fat, both are usually unhealthy. Fast food suppliers typically fry potatoes in cheap, unhealthy fat. Crinkle cut fries and thin fries absorb more fat while they're cooking and are therefore even more unhealthy than traditional, thick cut fries.
- Easy Low Fat Potato Recipes healthy ways to cook potatoes