Plantains look like bananas and cook like potatoes, and on keto they behave like the potato. A single medium plantain carries about 53 g of net carbs, more than two days of a strict keto budget, with under a gram of fat. Frying it in oil changes the calorie ratio but not the starch, and ripening it just turns the starch into sugar.
Under the Pure Keto™ Standard, plantains score Not Keto in every form: green or ripe, boiled, baked, fried as tostones or caramelized as maduros, and as chips. This guide gives the real numbers, explains the resistant-starch argument people use to defend green plantains, and lists the swaps that give you the same crunch or sweetness and score Pure Keto.
The Pure Keto™ score for plantains
The score box above is for a medium raw plantain. By calories it is about 3 percent fat, 4 percent protein and 93 percent net carbs. The Not Keto zone begins at 40 percent; plantain is more than twice that. The 4 g of intrinsic fiber is fully deducted under the Pure Keto Net Carb Standard, and the number is still 53.
Here is how the common preparations compare:
| Serving | Fat | Protein | Net carbs | Pure Keto zone |
|---|---|---|---|---|
| 1 medium raw plantain (179 g) | 0.7 g | 2.3 g | 53 g | Not Keto |
| 1 cup sliced ripe plantain, boiled (154 g) | 0.3 g | 1.2 g | 41 g | Not Keto |
| 1 cup baked plantain slices | 0.5 g | 1.5 g | 47 g | Not Keto |
| 3 tostones, fried green (about 100 g) | 12 g | 1.5 g | 20 g | Not Keto |
| 1 cup maduros, fried ripe (about 120 g) | 14 g | 1.5 g | 38 g | Not Keto |
| Plantain chips, 1 oz (28 g) | 9 g | 1 g | 17 g | Not Keto |
| Mofongo, 1 cup (mashed fried plantain, pork, garlic) | 18 g | 8 g | 45 g | Not Keto |
| 1 single tostone | 4 g | 0.5 g | 6 g | Not Keto |
| 2 tbsp green plantain flour | 0.2 g | 0.5 g | 12 g | Not Keto |
Frying adds 10 to 15 g of fat per serving, which pulls the ratio toward the fat corner of the triangle. It does not pull it far enough, and it does nothing to the 20 to 45 g of starch on the plate.
The green plantain and resistant starch argument
Green plantains are often recommended on low-carb forums because they are high in resistant starch, a form of starch that human enzymes cannot fully digest. That is real, and the Pure Keto Fiber Registry classifies raw high-amylose resistant starch (RS2, the type in green bananas and green plantains) as Tier 2, with a 50 percent deduction.
The catch is in the word raw. Nobody eats a raw green plantain. Heat gelatinizes resistant starch and converts most of it to ordinary digestible starch, which is why cooked green plantain has about the same effect on blood sugar as a boiled potato. Cooling cooked plantain re-forms a little of the resistant starch, but only a few grams' worth. A cup of cooked green plantain still lands at 40 g or more of net carbs after any honest deduction.
Ripe plantains do not even offer the argument. Ripening converts the starch to sucrose, glucose and fructose, which is why maduros taste like candy and why they hit the bloodstream faster than the green version.
How much plantain fits on keto
Realistically, none on a standard 20 to 30 g plan. The arithmetic:
- One tostone: about 6 g net carbs. Possible as the day's only carb spend, and unsatisfying.
- Three tostones (a normal side): about 20 g. A full strict day in one side dish.
- A cup of maduros: about 38 g. Will interrupt ketosis in most people.
- One whole plantain in any form: 45 to 55 g. Two days of carbs.
On a targeted ketogenic diet, where 25 to 50 g of fast carbs are eaten around a hard workout, a few tostones are a legitimate choice. On a cyclical plan they fit on the refeed day. On everyday keto they do not fit, and the Pure Keto Standard does not pretend otherwise.
Pure Keto swaps for plantains
Plantain dishes are about texture: the crunch of tostones, the caramel of maduros, the mash of mofongo. Each has a substitute that scores Pure Keto.
For tostones (crispy, salty, garlicky)
- Smashed fried radishes. Boil radishes until tender, smash flat, fry in lard or avocado oil until crisp, salt and garlic. About 1 g net carbs each. The closest match.
- Fried zucchini rounds dredged in parmesan. See our zucchini guide. About 2 g per rounds' worth.
- Fried cauliflower steaks in butter with garlic and lime.
- Pork rinds or chicharrones, which are already part of the same cuisine and have 0 g carbs.
- Spam chips or cheese crisps for pure crunch.
For maduros (sweet, caramelized)
- Roasted pumpkin or butternut squash cubes in butter, finished with cinnamon and a keto sweetener. About 5 to 7 g net carbs per half cup. Not zero, but a fifth of maduros.
- Pan-fried squash (summer squash or zucchini) with butter and a pinch of erythritol caramelizes surprisingly well.
- Grilled avocado with lime and salt for the soft, rich texture without the sugar.
For mofongo and mash
- Cauliflower mofongo. Mashed roasted cauliflower with garlic, olive oil and crushed chicharrones. About 5 g net carbs per cup and Pure Keto because of the fat.
- Mashed turnip or celery root with butter for a starchier texture, at 6 to 8 g per cup.
For plantain chips
- Pork rinds, cheese crisps, roasted macadamias, or seaweed snacks. See our popcorn guide for the full list of Pure Keto crunchy snacks.
Plantain products to know
- Plantain chips (Goya, Trader Joe's, Barnana): about 17 g net carbs per ounce. Not keto.
- Green plantain flour: used in paleo baking; about 12 g net carbs per 2 tablespoons. Not keto. Use almond or coconut flour.
- Frozen tostones and maduros: the same carbs as homemade plus whatever oil they were par-fried in.
- Plantain "keto" recipes online: these are almost always paleo or Whole30 recipes mislabeled. Plantain cannot be made keto.
The bottom line
Plantains are not keto friendly. A medium plantain has about 53 g of net carbs, three tostones about 20 g and a handful of chips about 17 g, and all of them score Not Keto under the Pure Keto Standard. The resistant starch in green plantains does not survive cooking. Fry radishes or zucchini for the crunch, roast pumpkin in butter for the sweetness, and mash cauliflower with chicharrones for mofongo.
Sources
- U.S. Department of Agriculture, FoodData Central. Plantains, raw (SR Legacy 169124); Plantains, cooked (SR Legacy 169125); Snacks, plantain chips, salted (SR Legacy 168001).
- Manufacturer nutrition panels for Goya Plantain Chips and Goya frozen tostones, accessed September 2026.
- Pure Keto Fiber Registry, KetoFriendly.com: Tier 2 classification of high-amylose resistant starch (RS2).
Frequently asked questions
Are plantains keto friendly?
No. A medium plantain has about 53 g of net carbs and almost no fat, and about 97 percent of its calories come from carbohydrate. It scores Not Keto under the Pure Keto Standard. That holds for green and ripe plantains, and for boiled, baked and fried preparations.
How many carbs are in plantains?
About 57 g total carbs and 4 g fiber in one medium raw plantain, so 53 g net carbs. A cup of sliced ripe plantain is about 47 g net carbs, and 100 g of fried tostones or maduros is roughly 30 to 45 g depending on the oil absorbed. Even a single tostone is 5 to 7 g.
Are green plantains lower in carbs than ripe ones?
Only slightly, and only raw. Green plantains hold more resistant starch, which counts at 50 percent under the Pure Keto Fiber Registry, but cooking converts most of it to regular starch. Ripe plantains have converted that starch to sugar. Cooked, both come out at 45 to 55 g net carbs per medium plantain.
Are plantain chips keto?
No. A one-ounce serving of plantain chips has about 17 g of net carbs and 9 g of fat. The oil raises the fat share, but 17 g of carbs in a small handful is not keto in any useful amount. Pork rinds, cheese crisps and roasted nuts are the crunchy alternatives.
Can I eat tostones on keto?
Three tostones, about 100 g, cost roughly 20 g of net carbs, which is a full strict-keto day in a side dish. If you have a higher carb allowance on a targeted or cyclical plan, a single tostone at 5 to 7 g is a possible spend. On standard keto, no.
What is a keto substitute for plantains?
For tostones, smashed fried radishes or fried zucchini rounds at 1 to 2 g net carbs each, or crispy Spam and cheese chips for crunch. For maduros, roasted butternut or pumpkin cubes in butter give a sweet caramelized bite at about 5 g net carbs per half cup. For mofongo, a base of mashed cauliflower with garlic and pork cracklings.
