High-Protein Lemon Loaf Recipe with Creamy Lemon Icing
Makes: 6 slices
Per Serving: 17g Protein | 222 Cal
There are certain recipes that just feel like sunshine in baked form, and for me, lemon loaf is one of them. It’s bright, zesty, and full of that refreshing lemony flavor, it’s the perfect treat for when you want something sweet without going overboard. But here’s the challenge: most lemon loaf recipes are loaded with sugar and lack any real protein. That’s where this recipe comes in.
This High-Protein Lemon Loaf is light, tender, and bursting with lemon flavor, but it’s also packed with 16 grams of protein per slice (17g if you add the icing). It’s perfect for breakfast, a mid-afternoon snack, or even a healthy dessert option that fits into your fitness goals.
This recipe didn’t happen overnight. In fact, this loaf was an audience request, and I’m not exaggerating when I say it took seven attempts to get it just right. The first few tries? Either too dense, too dry, or the flavor just wasn’t popping the way I wanted. But on the seventh attempt, I nailed it—the perfect balance of moisture, sweetness, and that soft, cake-like texture you expect from a good lemon loaf.
Why This Lemon Loaf Is Different
If you’ve ever tried making high-protein baked goods, you know the struggle: they can come out rubbery, dry, or overly dense. That’s why the protein blend in this recipe matters so much. I use a combination of whey protein isolate and casein protein, and here’s why:
Whey protein helps with rise and gives the loaf a lightness because it mixes easily and incorporates air.
Casein protein, on the other hand, is slow-digesting and absorbs more liquid, which means it helps retain moisture and gives the loaf structure.
When you combine them, you get the best of both worlds—a tender, moist crumb that’s not dry or chalky. It’s a game changer for high-protein baking.
Plus, this recipe uses oat flour for fiber and a touch of almond flour for richness without making it heavy. Combined with Greek yogurt and eggs for extra protein and moisture, this loaf is as nourishing as it is delicious.
Ingredients You’ll Need
Dry Ingredients:
1 cup (90g) oat flour or all-purpose flour (I used gluten-free)
1.5 scoops (45g) vanilla whey protein powder (I used Clean Simple Eats—code PROTEINSNACKQUEEN for $$ off)
2 scoops (30g) unflavored casein protein powder (I use Naked Casein)
2 tbsp (14g) almond flour
2 tsp baking powder
¼ tsp salt
Zest of almost all of 1 large lemon (save a little for the icing)
Wet Ingredients:
½ cup (115g) nonfat plain Greek yogurt
2 large eggs
2 tbsp (30g) coconut sugar
¼ cup (60g) maple syrup or sugar-free syrup
2 tbsp lemon juice
1 tsp vanilla extract
For the Icing:
3 tbsp powdered sugar
1–2 tsp softened light cream cheese (optional but recommended for thickness)
1 tbsp vanilla protein powder
1 tbsp lemon juice
Zest of lemon
Instructions
Preheat your oven to 325°F (163°C). Line a loaf pan with parchment paper or lightly spray it with nonstick spray.
In a large mixing bowl, add the oat flour, vanilla whey protein, unflavored casein protein, almond flour, baking powder, salt, and almost all of the lemon zest. Mix until combined and set aside.
In a separate bowl, whisk together the Greek yogurt, eggs, coconut sugar, maple syrup (or sugar-free syrup), lemon juice, and vanilla extract until smooth.
Slowly pour the wet ingredients into the dry ingredients, mixing gently with a spatula or spoon. Do not overmix—just stir until combined and smooth. The batter should be slightly thick but pourable.
Pour the batter evenly into your prepared loaf pan, smoothing out the top with a spatula.
Bake at 325°F for about 40 to 45 minutes. Start checking at 38 minutes. The loaf is ready when a toothpick inserted into the center comes out clean or with a few moist crumbs.
Remove from the oven and let the loaf cool in the pan for 10 minutes before transferring it to a wire rack or flat surface to cool completely.
While the loaf is cooling, prepare the icing. In a small bowl, mix the powdered sugar, light cream cheese, vanilla protein powder, lemon juice, and the remaining lemon zest until smooth. If the icing is too thick, add a few drops of lemon juice. If it’s too thin, add a little more protein powder or chill it in the fridge for 10–15 minutes.
Once the loaf is completely cool, spread the icing over the top. If you prefer a lighter glaze, omit the cream cheese—but know it will be thinner and less spreadable (as seen in the photo).
Slice into 6 portions and enjoy!
Nutrition Facts (Per Slice)
Makes 6 slices:
Without icing: 192 calories | 16g protein | 22g carbs | 5g fat (11g sugar)
With icing: 222 calories | 17g protein | 26g carbs | 6g fat (15g sugar)
Tips for Success
Do not skip the casein protein. If you use only whey, your loaf will likely collapse or come out dry. The casein is key for that perfect soft, moist crumb.
Zesting your lemon correctly is crucial. Avoid the white pith—it’s bitter. Only use the bright yellow part.
Cool the loaf completely before icing, or the icing will melt and slide off.
Make It Your Own
Swap Flavors: Try lime zest instead of lemon for a twist.
Add Poppy Seeds: Turn this into a high-protein lemon poppy seed loaf.
Top It Off: Add a drizzle of sugar-free white chocolate or sprinkle extra zest for presentation.
FAQs
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You can, but the texture will change significantly. The loaf will likely be more dry and less structured because whey alone does not retain moisture the way casein does. If you must use only whey, increase the Greek yogurt by 2–3 tablespoons to compensate.
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Yes. Use a plant-based protein blend that includes pea and pumpkin proteins (for structure) and swap Greek yogurt for a dairy-free alternative like coconut yogurt. Keep in mind, the flavor and texture will be slightly different and I am not sure how it will turn out!
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Without cream cheese, the icing will be more like a glaze—thin and drippy. Cream cheese helps thicken it and gives a richer mouthfeel. If you want a lighter option, you can skip it, but don’t expect that bakery-style icing texture.
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Absolutely. Slice the loaf, wrap each slice in parchment paper, and store them in an airtight freezer bag. Thaw in the fridge overnight or microwave for 15–20 seconds when ready to eat.
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Store the loaf in an airtight container in the fridge for up to 5 days. If you iced it, keep it chilled to prevent the icing from becoming runny.
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Combining a dry sweetener (coconut sugar) with a liquid sweetener (maple syrup) creates better moisture balance and enhances the flavor depth, preventing the loaf from tasting flat.
Final Thoughts
This high-protein lemon loaf is a recipe worth saving and making again and again. It’s light, zesty, and satisfying, with a tender crumb that feels indulgent but aligns with your health goals. Whether you enjoy it for breakfast, as a snack, or post-workout, this loaf is proof that healthy baking doesn’t have to mean compromising on taste or texture.
Want more high-protein, calorie-friendly baked treats? Check out my incredibly delcious Lemon Blueberry Protein Muffins, Protein Banana Bread, and Protein Pumpkin Muffins!
You can also grab a copy of my high-protien, low-calorie cookbook and guidebook here!
High-Protein Lemon Loaf Recipe with Creamy Lemon Icing
This High-Protein Lemon Loaf is light, zesty, and packed with 16 grams of protein per slice. Made with a blend of whey and casein for the perfect moist texture, it’s a healthy twist on a classic favorite. Topped with a tangy lemon icing that can be made thick and creamy or light and drizzly, this loaf is ideal for breakfast, snacks, or a guilt-free dessert.
Ingredients
- 1 cup (90g) oat flour or all-purpose flour (I used gluten-free)
- 1.5 scoops (45g) vanilla whey protein powder (I used Clean Simple Eats—code PROTEINSNACKQUEEN for $$ off)
- 2 scoops (30g) unflavored casein protein powder (I use Naked Casein)
- 2 tbsp (14g) almond flour
- 2 tsp baking powder
- ¼ tsp salt
- Zest of almost all of 1 large lemon (save a little for the icing)
- ½ cup (115g) nonfat plain Greek yogurt
- 2 large eggs
- 2 tbsp (30g) coconut sugar
- ¼ cup (60g) maple syrup or sugar-free syrup
- 2 tbsp lemon juice
- 1 tsp vanilla extract
- 3 tbsp powdered sugar
- 1–2 tsp softened light cream cheese (optional but recommended for thickness)
- 1 tbsp vanilla protein powder
- 1 tbsp lemon juice
- Zest of lemon
Instructions
- Preheat your oven to 325°F (163°C). Line a loaf pan with parchment paper or lightly spray it with nonstick spray.
- In a large mixing bowl, add the oat flour, vanilla whey protein, unflavored casein protein, almond flour, baking powder, salt, and almost all of the lemon zest. Mix until combined and set aside.
- In a separate bowl, whisk together the Greek yogurt, eggs, coconut sugar, maple syrup (or sugar-free syrup), lemon juice, and vanilla extract until smooth.
- Slowly pour the wet ingredients into the dry ingredients, mixing gently with a spatula or spoon. Do not overmix—just stir until combined and smooth. The batter should be slightly thick but pourable.
- Pour the batter evenly into your prepared loaf pan, smoothing out the top with a spatula.
- Bake at 325°F for about 40 to 45 minutes. Start checking at 38 minutes. The loaf is ready when a toothpick inserted into the center comes out clean or with a few moist crumbs.
- Remove from the oven and let the loaf cool in the pan for 10 minutes before transferring it to a wire rack or flat surface to cool completely.
- While the loaf is cooling, prepare the icing. In a small bowl, mix the powdered sugar, light cream cheese, vanilla protein powder, lemon juice, and the remaining lemon zest until smooth. If the icing is too thick, add a few drops of lemon juice. If it’s too thin, add a little more protein powder or chill it in the fridge for 10–15 minutes.
- Once the loaf is completely cool, spread the icing over the top. If you prefer a lighter glaze, omit the cream cheese—but know it will be thinner and less spreadable (as seen in the photo).
- Slice into 6 portions and enjoy!
Nutrition Facts
Calories
222Fat
6 gCarbs
26 gSugar
0 gProtein
17 gNutrition info is based off of estimates of both the lemon loaf and the icing. They are calculated by taking the ingredients in this recipe and dividing them by the number of servings.
