Can You Have Custard on a Keto Diet? The Ultimate Guide

November 8, 2025 •

2 min read

Over 75% of people on a keto diet miss classic desserts like custard, but it doesn't have to be off-limits. Yes, you can have custard on a keto diet by making a few simple substitutions to the traditional recipe, replacing high-carb ingredients with low-carb alternatives.

Quick Summary

Traditional custard is not keto-friendly due to its high sugar content and starchy thickeners. However, by swapping out ingredients like milk and sugar for heavy cream and keto-friendly sweeteners, you can create a creamy, low-carb version of custard that is delicious and fits your ketogenic lifestyle. The key is in the ingredients and preparation methods to avoid blood sugar spikes and maintain ketosis.

Key Points

Modify the recipe: Traditional custard relies on sugar and cornstarch, which must be replaced with keto-friendly sweeteners and thickeners like egg yolks or heavy cream.
Choose low-carb ingredients: Opt for heavy cream, unsweetened almond milk, or coconut cream instead of high-carb milk to form the base of your custard.
Utilize keto sweeteners: Effective zero-carb sweeteners for custard include erythritol, monk fruit, and allulose, which provide sweetness without affecting blood sugar.
Learn tempering technique: The key to a smooth, non-curdled custard is to temper the eggs by slowly introducing hot liquid, preventing them from scrambling.
Store properly: To avoid a "skin" from forming on the surface, press plastic wrap directly onto the custard before chilling it in the refrigerator.
Personalize with flavorings: Experiment with flavor variations by adding unsweetened cocoa powder, instant coffee, or spices like nutmeg and cinnamon.

Understanding the Traditional Custard Problem

Standard custard recipes are not suitable for a ketogenic diet primarily due to the high amounts of sugar and starchy thickeners like cornstarch they contain. Traditional milk also adds carbohydrates due to lactose. A ketogenic diet requires very low net carbohydrate intake, usually below 50 grams daily, making these traditional ingredients incompatible.

The Role of Sugar and Starch

Sugar is a pure carbohydrate that will significantly raise blood sugar. Cornstarch, a common custard thickener, is a high-glycemic starch with a considerable carb count. Regular milk contains lactose, contributing to carbohydrates, making heavy cream or low-carb alternatives better choices for keto.

Making Your Custard Keto-Friendly

To make a keto version of custard, simply replace the high-carb ingredients with low-carb alternatives.

Keto Custard Ingredients

Low-Carb Sweeteners: Use powdered erythritol, monk fruit, or allulose instead of sugar for sweetness without the carbs. Allulose is noted for its smooth texture.
High-Fat Dairy: Heavy cream is ideal for a creamy, low-carb base. Full-fat coconut cream works for dairy-free versions.
Low-Carb Milk Alternatives: Unsweetened almond milk can be used to adjust the consistency.
Eggs or Egg Yolks: These are natural, keto-friendly thickeners and add richness.
Optional Thickeners: A small amount of xanthan gum can enhance thickness without adding carbs, particularly in dairy-free recipes.

A Simple Keto Custard Recipe

Gently heat heavy cream or unsweetened almond milk with keto sweetener in a saucepan. Avoid boiling.
Whisk eggs or yolks with more sweetener in a separate bowl.
Temper the eggs by slowly whisking some hot cream into the egg mixture.
Combine tempered eggs with the remaining cream and cook on low heat, stirring until thickened.
Chill in ramekins or a dish, pressing plastic wrap onto the surface, until set.

Traditional vs. Keto Custard: A Comparison


Feature	Traditional Custard	Keto-Friendly Custard
Sweetener	Refined white sugar	Erythritol, monk fruit, allulose
Dairy	Full-fat or low-fat milk	Heavy cream, full-fat coconut cream, unsweetened almond milk
Thickener	Cornstarch, flour, egg yolks	Egg yolks, sometimes xanthan gum or gelatin
Carb Count	High	Very low (often 1-4g net carbs per serving)
Impact on Ketosis	Will likely break ketosis	Will not disrupt ketosis
Flavor/Texture	Creamy, sweet	Rich, creamy, satisfying

Creative Ways to Enjoy Keto Custard

Enhance your basic keto custard with variations.

Chocolate Custard: Mix in unsweetened cocoa powder.
Mocha Custard: Combine cocoa powder with instant coffee.
Serving with Berries: Top with a small amount of low-carb berries.
Spice it Up: Add nutmeg or cinnamon.

Conclusion: Satisfying Your Sweet Tooth the Keto Way

Yes, you can enjoy custard on a keto diet by modifying the traditional recipe. By substituting high-carb ingredients like sugar and milk with keto-friendly sweeteners and heavy cream, you can create a rich, creamy dessert that fits your ketogenic lifestyle. This allows you to indulge your sweet tooth without affecting ketosis. Explore resources like KetoDiet Blog for more keto dessert ideas.

Frequently Asked Questions

For custard, powdered erythritol, allulose, or a monk fruit blend are excellent options. Allulose is particularly good as it dissolves completely and doesn't leave a cooling aftertaste, but all three work well for creating a smooth, creamy texture.

No, most store-bought custards are not keto-friendly because they are made with high amounts of refined sugar and starchy thickeners like cornstarch, which will raise blood sugar and kick you out of ketosis.

You can make a dairy-free keto custard by replacing heavy cream with full-fat coconut cream or unsweetened almond milk. Using a high-fat coconut cream will ensure a rich and creamy texture.

Egg yolks are the traditional and most effective thickener for keto custard. For additional firmness, especially in dairy-free versions, you can add a small amount of xanthan gum or gelatin powder.

Custard often becomes lumpy or "eggy" if the eggs are not tempered properly or if the mixture is cooked over too high a heat. Always cook over a gentle, low heat and temper the eggs by slowly whisking in some hot liquid first.

Traditional custard powder is usually made with cornstarch and is not suitable for keto. However, some sugar-free versions exist, though it's crucial to check the ingredient list for hidden carbs. For true keto, making custard from scratch with heavy cream and eggs is the safest option.

To prevent a skin from forming, press a layer of plastic wrap directly onto the surface of the custard before you place it in the refrigerator to chill.