The advice to avoid fruit entirely is usually wrong. What matters more is which fruit, how much, and what you eat it with.
Guava is the standout. High fibre, low glycaemic load, widely available here for most of the year, and cheap. If you are picking one fruit to build a habit around, this is a sensible one.
Pear and apple are both reliable, particularly eaten with the skin on. The fibre in the skin is doing most of the work, so peeling them costs you much of the benefit.
Portion matters more than the fruit itself. Two hundred grams of almost anything spread through the day behaves very differently from half a kilo of mango in one sitting after lunch.
This is general guidance, not medical advice. If you are on medication for diabetes, talk to your doctor before you change anything — and our nutritionists will work around whatever they tell you.