The Core Science: Fiber Is a Carbohydrate
To understand why a food-tracking app like MyFitnessPal counts fiber in its carbohydrate total, you must first grasp the basic scientific classification of macronutrients. Carbohydrates are one of the three main macronutrients, alongside fats and proteins. They are organic compounds made of carbon, hydrogen, and oxygen and are a primary energy source for the body.
Within the broad category of carbohydrates, there are several sub-types. These include sugars (simple carbs), starches (complex carbs), and fiber. From a purely chemical standpoint, fiber fits the definition of a carbohydrate, even if your body processes it differently. The key difference is that while simple and complex carbs are broken down into glucose and absorbed for energy, the rigid structure of fiber resists digestion.
Different Types of Fiber
Fiber itself is not a single entity but can be divided into different types based on how it interacts with water.
- Soluble Fiber: This type dissolves in water to form a gel-like substance in the digestive system. It can help lower blood cholesterol and glucose levels and is found in oats, beans, apples, and carrots.
- Insoluble Fiber: This type does not dissolve in water and adds bulk to stool, helping to regulate bowel movements and prevent constipation. Good sources include whole-wheat flour, nuts, and many vegetables.
Despite their different roles, both soluble and insoluble fiber are chemically classified as carbohydrates. This classification is a key factor in how nutritional information is presented on food packaging and, consequently, within nutrition-tracking apps.
Navigating Food Labels and App Data
Nutrition labels and food-tracking apps must adhere to specific regulatory guidelines. In the United States, the Food and Drug Administration (FDA) requires that the total carbohydrate count on a label includes all carbohydrate types, including sugars, starches, and dietary fiber. This is why your packaged food label shows a "Total Carbohydrate" value with a separate, indented listing for "Dietary Fiber" underneath it.
MyFitnessPal's calculation method reflects this regulatory standard. When you add food from a scannable barcode or a verified database entry, the app uses the total carbohydrate number as its baseline. This ensures consistency with the official nutritional information provided by food manufacturers.
The Impact of User-Generated Data
One of MyFitnessPal's strengths is its enormous, user-generated food database. However, this can also be a source of inconsistency and error. Some users manually enter foods, and if they enter the data incorrectly—perhaps only listing net carbs—it can create discrepancies. This is why it's always a good practice to double-check against the product's official nutrition label or look for entries in the app's database that have been marked as verified.
Total Carbs vs. Net Carbs
The concept of "net carbs" is not a legally defined term by the FDA but is popular in low-carb and ketogenic diet communities. Net carbs are calculated by subtracting the grams of fiber and, in some cases, sugar alcohols from the total carbohydrates, based on the idea that these components do not significantly impact blood sugar levels.
MyFitnessPal's standard (free) version tracks total carbs, requiring users to manually subtract fiber if they want to track net carbs. However, MyFitnessPal Premium offers a specific "Net Carbs Mode" that automatically performs this calculation for you, a major benefit for those on strict low-carb diets.
How to Manage Carb Tracking in MyFitnessPal
For accurate macro tracking, especially regarding carbs and fiber, consider the following strategies:
- Prioritize Verified Entries: When using the MyFitnessPal database, opt for foods with a green checkmark next to them. These are typically verified entries that provide more accurate nutritional data.
- Use a Barcode Scanner (Premium): The barcode scanner function, a premium feature, significantly improves accuracy by pulling information directly from the product, minimizing the risk of human data-entry errors.
- Manual Net Carb Calculation: If you don't have a Premium subscription and are on a low-carb diet, you'll need to calculate net carbs yourself. You can easily do this by taking the 'Total Carbohydrates' from the nutrition facts and subtracting the 'Dietary Fiber'. If the label includes sugar alcohols, you'd subtract those as well.
- Create Custom Foods: If you find a food with an inaccurate entry or want to save a manually calculated net carb value, create a custom food entry within the app. This allows you to log the correct data every time you consume that item.
Comparison Table: Total Carbs vs. Net Carbs
| Feature | Total Carbs | Net Carbs |
|---|---|---|
| Definition | The sum of all carbohydrate types, including fiber, sugar, and starch. | The total carbohydrates minus fiber and sugar alcohols. |
| Regulation | Legally defined and required on nutrition labels by the FDA. | Primarily a marketing term; not legally defined or regulated by the FDA. |
| Digestion | Includes both digestible and indigestible carbohydrates. | Focuses only on the carbohydrates that significantly impact blood sugar. |
| Relevance | Important for general nutrition tracking, overall dietary intake, and for those not on strict low-carb diets. | Crucial for those on ketogenic or low-carb diets who need to minimize their blood sugar impact. |
| Tracking in MFP | MyFitnessPal tracks this automatically by default. | Can be tracked manually in the free version or automatically with a Premium subscription. |
Conclusion: Clarity for Better Tracking
In summary, the reason why MyFitnessPal counts fibre as carbs is because it's following the standard nutritional science and food labeling regulations. Fiber, despite its indigestible nature, is fundamentally a carbohydrate. For most people focused on general health and a balanced diet, tracking total carbs is a perfectly adequate method. However, for those on specific diet plans like keto, understanding the distinction and using MyFitnessPal's features (such as Premium's Net Carbs Mode) or manual calculations is essential for accurate monitoring. By understanding the core principles, you can make smarter, more informed choices about your nutrition and ensure your food diary accurately reflects your dietary goals.
For more in-depth information about carbohydrates and other nutrients, a reputable resource like the Harvard T.H. Chan School of Public Health's nutrition section can be valuable. The Nutrition Source: Carbohydrates.
