Custom Food Challenges

Custom Challenges in the FoodMarble App

If you enjoy exploring every feature of an app, you may have already discovered the Custom Challenges option in the Discovery section of the FoodMarble app. If not, it’s a feature well worth trying.

Custom Challenges give you the flexibility to test real foods in real portions, helping you understand your personal tolerance to a specific food. They take you beyond standard FODMAP testing, allowing you to see in real time how your digestive system responds to the foods you actually eat.

What is a Custom Challenge?

A custom challenge is a structured test designed to measure your personal response to a specific food. It works just like the standard food intolerance challenges, with a few key differences:

Preparation:

• Eat a low FODMAP diet the day before.
• Fast for about 12 hours before starting (usually overnight).

Challenge Day:

• Instead of taking a standard FODMAP test packet, you eat a food of your choice in a chosen portion size (e.g. one Pink Lady apple, 100g of cooked leek, or a glass of milk).
• You log the food and portion size in the app.

Testing:

• Just like a standard challenge, you’ll be prompted to take a breath test every 15 minutes over a 3-hour period.
• At the end, your results appear in the app, showing whether the food triggered fermentation in your gut.

Who Should Try a Custom Challenge?

Custom challenges can be helpful for different types of users:

Beginners: If you’re new to FoodMarble and not ready to start with the full intolerance tests, you can use a custom challenge to test a food you regularly eat but suspect causes symptoms (e.g. garlic, leeks, apples, beans).

After Completing the Four Standard Tests:

If you’ve already tested Lactose, Fructose, Sorbitol, and Inulin, custom challenges are a natural next step.

Custom Challenges let you go deeper, exploring:

• How much of a food you can tolerate (your personal threshold).
• Which additional FODMAPs, like FOS, GOS, or Mannitol, may affect you.

For example, if your lactose challenge showed a high result, that doesn’t necessarily mean you must avoid lactose completely. Instead, you can run custom challenges with smaller amounts (like one glass of milk instead of two) to find out how much you can handle without symptoms.

Finding Your Personal Tolerance

Tolerance to FODMAPs is rarely “all or nothing.” Most people can handle at least a small amount of any given FODMAP — the challenge is discovering your personal threshold.

Take lactose as an example:

• The lactose test pack contains 25g of lactose (about the same as two large glasses of milk).
• If this triggered high readings and symptoms, you might try a custom challenge with just one glass of milk.
• If that’s well tolerated, you could gradually test higher amounts.
• If even a smaller portion triggers symptoms, you may want to test with less — or adjust how and when you consume lactose-containing foods.

This stepwise approach gives you practical, real-world answers about what you can enjoy safely, rather than cutting out entire food groups unnecessarily.

Why Custom Challenges Matter

A diverse, plant-rich diet supports a healthy gut microbiome. Vegetables, fruits, legumes, nuts, and seeds all provide essential fiber and nutrients. However, many of these foods also contain FODMAPs — meaning they may provoke fermentation and trigger symptoms if your tolerance is exceeded.

That’s where custom challenges shine:

• They help you separate healthy foods you can include in moderation from those that consistently trigger symptoms.
• They allow you to test real foods in real portions, not just FODMAP powders in high concentrations.
• They provide a clearer picture of your digestion, so you can build a diet that supports both your gut health and your comfort.

Key Takeaway

Custom challenges are a practical, flexible way to personalize your diet.

They empower you to:

• Identify trigger foods
• Discover your individual tolerance thresholds
• Keep your diet as varied and nutritious as possible

Rather than eliminating whole food groups, you can use custom challenges to find your balance — enjoying more of the foods you love while minimizing discomfort.

Updated on: 19/08/2025