Fruits

Berries lead the list: raspberries and blackberries contain roughly 4–5 g of sugar per 100 g, and strawberries about 5 g. Avocado is technically a fruit with under 1 g of sugar per 100 g, and lemons and limes come in around 2 g. These options also tend to have a lower glycemic index, especially when eaten whole with their fiber.

Most fruits exceed the typical 20–50 g daily carb limit quickly, so they are limited on strict keto. The usual exceptions are small portions of berries (raspberries, blackberries, strawberries) and avocado, which is high in monounsaturated fat and very low in net carbs. Bananas, grapes, mangoes, and dried fruits like dates are generally avoided due to concentrated sugars.

Guava tops the list at around 200 mg of vitamin C per 100 g, followed by blackcurrants (about 180 mg) and kiwi (around 90 mg). Citrus fruits like oranges and grapefruit provide 30–50 mg per 100 g, and strawberries deliver roughly 60 mg. A single kiwi or a cup of strawberries already covers the adult daily reference intake of 75–90 mg.

Dried fruit concentrates both nutrients and sugars: 100 g of raisins contains about 60 g of sugar versus around 16 g in fresh grapes, with a correspondingly higher caloric density. Fresh fruit has more water, a lower glycemic load per serving, and intact vitamin C, which degrades during drying. Dried fruit still provides fiber, potassium, and iron, but portions are typically much smaller, around 30 g.