The reason why a doctor would tell you not to eat potatoes is for managing blood sugar, controlling your calorie intake or even to reduce stress on the kidneys.
Potatoes are a starchy vegetable and are highly glycemic and can cause negative interactions with certain medications as well.
Potatoes can cause rapid blood sugar spikes, which is a problem in people with diabetes, prediabetes or even insulin resistance so doctors may tell you to not eat potatoes or limit your potato intake.
The high starch content of amylopectin in potatoes also converts to glucose very quickly, which makes your glucose levels difficult to manage without medication or dietary adjustments.
Doctors may also tell you to not eat potatoes or limit potato intake for weight loss and calorie control.
Potatoes have a high carbohydrate density and for example a standard baked or mashed potato also behaves like a heavy carbohydrate, which can result in unwanted weight gain if portion sizes are not monitored.
And doctors also often restrict potatoes because potatoes are commonly eaten in high calorie and high fat forms of foods like French fries, baked potatoes loaded with butter and sour cream and potato chips.
Doctors also tell people with poor kidney function or kidney disease to avoid potatoes due to the potassium.
Potatoes are rich in potassium and so doctors will routinely restrict or even ban potatoes in a kidney patients diet and for those on dialysis as the kidney patients body cannot filter excess potassium properly.
Doctors may also tell you to not eat potatoes if you're on blood thinners.
Potatoes contain a chemical, which can decrease blood clotting and eating potatoes in large quantities alongside of thrombolytic drugs, which are medications for dissolving blood clots like reteplase or alteplase, which can increase your risk of bruising and bleeding.
And some people also have autoimmune or inflammatory conditions or even potato allergies.
Although rare, some people have a true food allergy to potatoes, which can cause rashes, difficulty breathing or anaphylaxis and so people with potato allergies should avoid potatoes.
Some doctors and dietitians also suggest avoiding potatoes and other nightshade vegetables when you have specific autoimmune or inflammatory bowel disease if you experience gut irritation.
And doctors will also tell you to discard potatoes which have sprouted or turned green as these signs indicate a buildup of solanine, which is a neurotoxin that can cause severe gastrointestinal distress.