After the first phase of the Atkins diet, when no fruit at all is permitted, small amounts of berries and similar fruits, such as strawberries, can be included. Later stages allow the introduction of low-carb fruits such as kiwi and lemon.
Most low carb diets, including Atkins, severely restrict the types and quantities of fruits their users can eat. This is because, although fruit is generally good at providing nutrition in the form of fiber, vitamins and minerals, this comes with a hefty dose of fructose, a simple carbohydrate that the body uses for fuel.
Berries, because of their low glycaemic impact and additional fiber due to the higher skin to flesh ratio, are some of the best fruits to fit into a very low daily carb allowance. Other high fiber fruits that contain fewer carbs per gram include oranges, as long as all of the flesh is consumed, and passion fruits.
Less sweet fruits that can be used in cooking, such as coconut and avocado, are also suitable to include after the first phase of the Atkins plan, as they have lower overall carb contents. Tomatoes are somewhere in between, so they should be used sparingly until the pre-maintenance stage.