Answer: Watermelons are not keto, as they're packed with sugar.
If you have fond memories of enjoying watermelon on a hot summer day, brace yourself for some tough news: watermelons are not keto.
A single 280 g serving of watermelon (roughly one watermelon wedge) contains over 20 g of net carbs. That's high enough to interfere with your ketosis even if it's the only food you eat for the day.
There aren't a ton of fruit options on keto, but you do have some keto-friendly choices: