Peanut Butter Banana Smoothie

Michael Eisenwasser

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A single-serve peanut butter banana smoothie using Monash serve sizes for the banana, peanut butter, and milk. Banana ripeness matters here.

Prep 5 min

Cook 1 min

Serves 1

Gluten-freeVegan-option

Ingredients

• 1 firm-yellow banana (about 100 g), still slightly green at the stem
• 2 tablespoons (about 32 g) smooth peanut butter, no honey or added fiber
• 1 cup (250 ml) lactose-free cow's milk or unsweetened almond milk
• 1/2 cup ice
• 1/2 teaspoon pure vanilla extract (optional)
• 1 teaspoon pure maple syrup (optional)

Instructions

Blend

1. Add the milk first, then the banana, peanut butter, ice, vanilla, and maple syrup.
2. Blend on high for 45 to 60 seconds, until the peanut butter is fully broken up and the drink is smooth.
3. Pour into a tall glass and drink right away. It thickens for a minute or two, then thins as the ice melts.

Tips & Substitutions

• Pick the right banana. Firm-yellow, still slightly green at the stem, is the low-FODMAP serve at 1 whole banana (about 100 g). Once the peel hits spotty-ripe, Monash drops the serve to 1/3 of a banana (about 35 g). Use a firm one, or freeze firm-yellow slices so you have some ready.
• Check the peanut butter label. Plain peanuts and salt is what you want. Skip jars with honey, agave, inulin, chicory root fiber, or "prebiotic fiber" added. A 2 tablespoon (about 32 g) scoop is the low-FODMAP serve.
• Make it a protein smoothie. Add 1 scoop of whey isolate, rice protein, or egg-white protein powder. Skip plant-protein blends like Orgain, Vega, and Garden of Life. Many contain inulin or chicory root fiber, which is high-FODMAP. Check the label for "prebiotic fiber" and polyol sweeteners too.
• Pick a safe milk. Lactose-free cow, unsweetened almond (up to 1 cup / 250 ml), macadamia, hemp, or rice milk (up to 3/4 cup / 187 ml). Canned light coconut milk is low at 1/2 cup. Oat milk is brand- and serve-dependent; use a Monash-certified carton or skip it. Avoid any milk with inulin, chicory root fiber, or added "prebiotic fiber."
• Make it chocolate peanut butter. Stir in 2 teaspoons (about 8 g) of unsweetened cocoa or cacao powder before blending. That amount fits the low-FODMAP serve and makes it taste more like a milkshake with the peanut butter and banana.
• Freeze the banana. Peel a firm-yellow banana, slice it, and freeze on a tray. Frozen banana plus ice makes a thicker, colder smoothie without needing yogurt.
• Sweeten with maple syrup only. Honey and agave are high-fructose and not low-FODMAP. A ripe-enough banana and the peanut butter are usually sweet enough on their own.

Why This Works

Banana ripeness matters more than size. Monash lists 1 whole unripe banana (about 100 g) as low-FODMAP, but once a banana ripens, fructans go up quickly. Ripe (spotty) banana drops to a 1/3 banana serve, about 35 g. That's a big difference in a smoothie. Using a firm-yellow banana, still slightly green at the stem, is the difference between a glass that sits well and one that might not.

Peanut butter serve. Peanuts are a true low-FODMAP nut, and 2 tablespoons (about 32 g) of plain peanut butter sits comfortably at the low serve. The main issue is added ingredients. Some brands add honey, agave, inulin, or chicory root fiber for sweetness or "gut health," all of which are high-FODMAP. Read the ingredient list and stick to jars that list peanuts and salt.

Milk matrix. Lactose is the FODMAP issue in regular cow's milk. Lactose-free dairy and most unsweetened nut milks are low at 1 cup, which is why this recipe pours a full glass without splitting the volume.

Protein-powder trap. Most plant-protein blends sold to gym and wellness shoppers contain inulin or chicory root fiber. Both are high-FODMAP fructans, and they show up even in "clean" or "gut-health" labels. Whey isolate, rice, and egg-white powders are the safer defaults if you want to turn this into a post-workout drink.

Sweetener rule. A firm-yellow banana plus peanut butter is usually sweet enough. If it isn't, pure maple syrup is low-FODMAP at 2 tablespoons, so a teaspoon lands well inside the safe range. Honey and agave are both high-fructose and don't belong in this glass.

Storage

Blend and drink right away. If you need to hold one, cap it in a sealed container and refrigerate for up to 24 hours at 40°F (4°C) or below. Shake or re-blend before drinking; the peanut butter and banana separate as they sit. To prep ahead, freeze sliced firm-yellow banana in a zip bag and add milk, peanut butter, and ice at blend time.

Not sure about an ingredient? FODMAP Tracker includes a database of 1,000+ foods with FODMAP ratings to help you cook with confidence.