There's no denying that the keto diet is all the rage; the high-fat, moderate-protein, superlow-carb diet has helped countless people lose impressive amounts of weight [1]. By cutting back so drastically on carbs, the keto diet turns to burning fat for fuel instead of carbs, which puts your body into the fat-burning state of ketosis [2].
On the keto diet, you should eat 50 grams or fewer of carbs a day [3]. So what does that mean for the foods you can eat? Surprisingly, fruit, which is higher in carbs and fructose than many other natural whole foods, isn't off-limits; you just need to be careful which fruits you decide to eat. Take watermelon, for example: the delicious Summer treat clocks in at 22 grams of carbs and 18 grams of sugar, with less than two grams of fibre per two-cup serving.
"This amount of sugar and carbs can raise blood sugar and insulin levels and shut off ketone production," registered dietitian Sarah Koenck, member of the clinical team at Virta Health [5], told POPSUGAR. "To maintain nutritional ketosis [6], most people need to stick with around 50 grams of carbs or less. Given the high-carb content in watermelon, it is not a good option to include in your ketogenic meal plan."
Instead, Sarah recommends eating other lower-sugar fruits [7], such as berries (blueberries, blackberries, and raspberries), tomatoes, and avocados on the keto diet. In general, the keto diet should consist primarily of leafy greens and non-starchy vegetables, meat and protein, fats, nuts, and oils, and full-fat dairy.
Of course, you don't need to swear off watermelon forever — a bite or two won't throw you out of ketosis. Talk with your doctor or registered dietitian to figure out the best way to do a ketogenic diet for your lifestyle.