Fruit ripeness, seasonality, storage, safety, nutrition and practical signs of quality.
Bananas became strongly associated with potassium because they are convenient, inexpensive, portable, and common in sports nutrition—not because they contain more than every other food. A medium banana provides about 420 mg, a useful amount that many foods and servings can exceed.
One hundred grams of avocado provides about 14.7–15 g of fat: roughly 9.8–10 g monounsaturated, 1.8 g polyunsaturated and 2.1 g saturated. A 50 g portion provides about 7.3 g of fat, while an avocado with 200 g of edible flesh contains close to 29 g. That is why 'one avocado' is not a useful fixed serving without knowing its size.
Avocado production can create significant environmental pressure when irrigation draws on scarce water or orchards expand into forest. There is no universal 'liters per avocado' number: research in Michoacán has found roughly 417 m³ of water per metric ton for rainfed orchards and more than 1,000 m³/t for irrigated production. Origin and farming system matter more than the fruit in isolation.
For most people, avocado can fit into a balanced diet every day. A 100 g portion provides about 160 calories, 15 g of fat—mostly monounsaturated—6–7 g of fiber and roughly 480 mg of potassium. The important question is not whether avocado is 'healthy' in isolation, but how much you eat and what it replaces.
Fresh fruits highest in fiber include passion fruit, avocado, raspberries, guava, and blackberries. Per 100 g they can provide roughly 5–10 g fiber, compared with about 2–3 g in apples, oranges, or bananas. Serving size changes the practical ranking: 1 cup of raspberries provides about 8 g fiber, while 100 g of passion-fruit pulp takes several fruits.
When the surface of a recently cut avocado turns brown, it is usually enzymatic oxidation rather than spoilage. The appearance changes much faster than the overall nutrition. You can scrape away a thin layer if you dislike the taste or texture. Mold, a rotten or strongly fermented smell, pronounced slime or deep widespread deterioration point to a different problem.
Avocado provides about 160 calories per 100 g — roughly three times the calories in an apple or orange by weight. That does not mean avocado automatically causes weight gain; portion size and total energy balance matter.
Most of the fat in avocado is monounsaturated, especially oleic acid. It also contains smaller amounts of polyunsaturated and saturated fat. Calling it a source of “healthy fat” refers mainly to that fatty-acid profile and the whole-food matrix, not to an absence of calories.