Answer: French fries are, sadly, totally incompatible with keto.
As much as we all love french fries, they unfortunately don't fit into keto.
French fries are just fried potatoes, a starchy, high-carb root vegetable. Even small amounts of french fries risk throwing you out of ketosis. A medium order of McDonald's french fries contains a whopping 40 g of net carbs.
For a keto-friendly side to your meal, consider pork rinds, Whisps, or zucchini fries.