Can I carb load with french fries? An athlete's guide to smart fueling

October 31, 2025 •

4 min read

For endurance events lasting over 90 minutes, such as a marathon or triathlon, a proper carb-loading strategy can boost performance by maximizing muscle glycogen stores. This critical pre-race fueling is often mismanaged, leading many athletes to ask, can I carb load with french fries and other popular but unsuitable foods.

Quick Summary

French fries are not recommended for carb loading due to their high fat content, which slows digestion and can cause gastrointestinal issues. Athletes should choose low-fiber, easily digestible carb sources to maximize glycogen stores for endurance events lasting over 90 minutes.

Key Points

High Fat Content: French fries are high in fat from the frying process, which slows digestion and can cause stomach distress during a race.
Inhibits Carb Intake: The high fat and fiber in fries can make you feel full too quickly, preventing you from reaching your necessary carbohydrate targets for carb loading.
Choose Low-Fat Carbs: Opt for easily digestible, low-fiber carbohydrate sources like baked potatoes, white rice, pasta, or sports drinks instead of fried foods.
Practice Before the Race: Never try a new nutritional strategy on race day; practice your carb-loading diet during training to see how your body reacts.
Save Fries for Recovery: French fries are better suited as a post-race treat, when their energy and sodium can aid in recovery, rather than pre-race fueling.
Optimal Fueling for Endurance: Effective carb loading is crucial for endurance events over 90 minutes and requires maximizing glycogen stores with the right kind of carbohydrates.

The Science of Carb Loading

Carbohydrate loading is a well-established nutritional strategy designed to maximize the storage of glycogen in the muscles and liver before a long-duration endurance event. Glycogen is the body's primary fuel source for high-intensity exercise, and having full stores is crucial for preventing fatigue and 'hitting the wall' during races lasting more than 90 minutes. A typical carb-loading protocol involves increasing carbohydrate intake to between 7 and 12 grams per kilogram of body weight per day, usually for 24 to 48 hours before the event. During this time, fat and fiber intake is reduced to avoid digestive issues and make room for the high volume of carbohydrates needed.

Why French Fries are a Problem for Carb Loading

While potatoes are an excellent source of carbohydrates for athletes, the way French fries are prepared makes them a poor choice for pre-race fueling. The main issue lies in their high fat content, which is a result of deep-frying. This added fat can significantly hinder your carb-loading efforts for several key reasons:

Slows Digestion: Fat takes a long time to digest and empty from the stomach. During a high-intensity event, blood is diverted from the digestive system to the working muscles. If your stomach is still full of greasy food, it can lead to discomfort, bloating, and other gastrointestinal distress that can ruin a race.
Makes You Feel Full Prematurely: High-fat, calorie-dense foods like French fries can make you feel satiated before you've consumed enough carbohydrates to meet your loading target. It's already a challenge to eat the large volume of carbs required for a proper load, and filling up on fat makes it even harder.
Excess Calories Without Glycogen: Since fat contains nine calories per gram compared to four for carbs, a high-fat meal can cause you to overshoot your energy needs without contributing significantly to glycogen storage. This can leave you feeling heavy and sluggish on race day, counteracting the purpose of carb loading.
High Fiber Content: Fries, especially with the skin on, can contain more fiber than is desirable for carb loading. While fiber is generally healthy, excess fiber during the 24-48 hours before a race can increase the risk of an upset stomach and unwanted bathroom stops.

Better Alternatives for Fueling Your Race

Instead of fatty French fries, focus on easily digestible, low-fiber, and low-fat carbohydrate sources to effectively top off your glycogen stores. These options provide the necessary fuel without the digestive risks.

Foods to Include

White Rice: Easily digestible and a staple for many athletes during carb-loading.
White Pasta: A classic choice, especially with a simple tomato-based sauce rather than a creamy, high-fat one.
Baked Potatoes: A plain, baked potato (without butter, sour cream, or other fatty toppings) is an excellent carb source.
Bagels and White Bread: Low in fiber and easily consumed in large quantities.
Low-Fiber Cereals: Options like cornflakes provide readily available carbohydrates.
Fruits and Juices: Low-fiber fruits like bananas and fruit juice are great for boosting carb intake and hydration.
Sports Drinks: Can help meet high carb targets when solid food feels too bulky.

Foods to Avoid or Limit

French Fries and Fried Foods: High in fat, slow to digest.
High-Fat Meats: Burgers and other fatty meats can cause digestive issues.
Creamy Sauces: Added fat that hinders digestion.
High-Fiber Vegetables: Raw broccoli, cauliflower, and legumes can be hard on the stomach.
Sugary Treats: While they contain carbs, foods like doughnuts and milkshakes often have high fat content and offer little nutritional value.

Practicing Your Carb-Loading Strategy

Just as you practice your running pace, it's essential to practice your nutritional strategy during your training. Use your long training runs to experiment with different food options and find what your body tolerates best. This prevents any unwelcome surprises on race day. A simple baked potato with a little salt (which can help with electrolyte balance) is a far safer bet than a basket of French fries. For more detailed guidance, consider visiting the Gatorade Sports Science Institute for expert sports nutrition insights (GSSI Sports Science Exchange).

French Fries vs. Baked Potato for Carb Loading


Feature	French Fries	Baked Potato	Reason for Difference
Fat Content	High	Low (if prepared without added butter/fat)	Frying adds significant fat, which delays digestion.
Fiber Content	Moderate to High (if skin is included)	Moderate (unless skin is removed)	Frying doesn't change fiber much, but the high-fat and volume can exacerbate fiber's effects.
Glycemic Index	Moderate to High (~54-75)	High (can vary based on prep)	Both have carbs, but fat in fries changes how they're processed.
Digestibility	Slow and difficult	Quick and easy	The high fat content in fries significantly slows gastric emptying, risking GI issues.
Satiety	High (due to fat)	Moderate (due to carbs and fiber)	Fat makes you feel full quicker, hindering the high carb intake needed for loading.

Conclusion: The Bottom Line for Athletes

While it's tempting to think of French fries as a quick and tasty source of carbohydrates, they are not a suitable food for effective carb loading. The high fat content is the primary culprit, jeopardizing your performance by slowing digestion, risking gastrointestinal problems, and making it difficult to consume the volume of carbohydrates needed to top off your glycogen stores. For optimal race-day performance, stick to a low-fat, low-fiber strategy using proven foods like baked potatoes, white rice, and pasta. Save the French fries for a post-race celebration, when their high energy and sodium content might even be beneficial for recovery. By making smart, science-backed nutritional choices, you can ensure your body is fully fueled and ready to perform at its peak.

Frequently Asked Questions

French fries are not recommended for carb loading because they are high in fat. The frying process adds a significant amount of fat that slows digestion, can lead to gastrointestinal discomfort, and fills you up before you can consume enough carbohydrates to maximize your glycogen stores.

A plain baked potato is a much better choice. The baked potato is a excellent, low-fat source of carbohydrates, unlike its fried counterpart. Other good options include white rice, white pasta with a low-fat sauce, bagels, and sports drinks.

The high fat content in French fries delays stomach emptying and slows down digestion. This can divert blood flow from your muscles to your digestive system during exercise, causing feelings of sluggishness, bloating, and potential stomach cramps.

The best carbs for carb loading are low-fiber, easily digestible sources. These include simple carbohydrates found in white bread, pasta, white rice, low-fiber fruits (like bananas), and sports drinks. The goal is to ingest a high volume of carbs without digestive issues.

While fat is a fuel source for low-intensity exercise, a high-fat diet is not recommended for carb loading. The goal is to maximize glycogen stores for later use. Fat can still cause digestive issues and hinder your ability to eat enough carbohydrates.

While athletes do need sodium to replace electrolytes lost through sweat, French fries are not the best way to get it. It is better to use controlled sources like electrolyte drinks and salted pretzels or crackers during a workout. The sodium content in fast-food fries is often excessively high and accompanied by problematic fat.

For endurance events, you should begin your carb-loading phase approximately 24 to 48 hours before the competition. This timing allows for adequate glycogen storage without requiring a longer, more restrictive dietary routine.