French Fries on a Diet: How To Indulge Wisely Without Derailing Your Weight Loss Goals

Weight Loss & Diets | Written by Nathan Petitpas | Updated on 8 July 2024

A man takes a bite from a large serving of fast food French fries, pondering if he can still lose weight while eating them.

Although some may wonder if they can eat anything on a calorie deficit, it’s best to eat mostly healthy foods, though the occasional cracker shouldn’t ruin a diet.

While French fries aren’t great for dieting, you can technically eat anything and still lose weight as long as there’s more calories being burned than consumed. That’s right, nothing is off limits but knowing how often you can eat French fries and the health implications can help guide you to better results.

Can You Eat French Fries Regularly & Still Lose Weight?

You can eat French fries and still lose weight, but the frequency at which you can eat them while continuing to see weight loss progress is the key consideration.

Eating French fries everyday can impede weight loss results, but eating them once a week or month shouldn’t have any ill effect on losing weight. Although, it all comes down to how many calories you eat on a daily and weekly basis and whether or not you’re eating healthy the remainder of the time.

For example, if you eat one French fry everyday while eating the rest of the time, you should still see great results. However, if you eat a large French fry or half of your daily calories from French fries each day, you’re more than likely going to see weight gain. Or in other words, the key is moderation.

However, if you’re set on eating French fries every single day, it’s best to eat them at times where our body can use that energy source most effectively.

When Is The Best Time To Eat French Fries on a Diet?

The best time to eat a carb-heavy snack like French fries is 30-60 minutes before a workout. Especially for short, high-intensity exercises, your body’s glycogen stores act as your primary source of energy and are beneficial for strenuous activities.1

Fries are mostly simple carbs, so they replenish your glycogen stores as your body metabolizes them.2 Any French fries work for this – regular, curly, shoestring, wedges, or even waffle fries.

Try to eat fries only once a week or less and consume healthier pre-workout snacks, like fruits, on other days. If you really can’t resist, though, a couple of French fries before your workout won’t harm you in the long run.

Why French Fries are Bad for Weight Loss

Sure, you can eat French fries in moderation while on a diet, but from a health perspective, they aren’t ideal due to their high calorie content, saltiness, and being fried, which all negatively impact fitness and weight.

Deep-Fried and Calorie Dense

French fries are deep-fried in oil, which adds a lot of calories and fried foods also contain trans fats, which increase your risk of diseases like heart disease, stroke, inflammation etc.3 The difference is stark – while 100 grams of baked potatoes are just 93 calories, the same amount of fries is 319 calories!4, 5

A small pack of McDonald’s fries is around 80 g, making it around 250 calories! That’s a small meal if you’re dieting, but it’s not half as filling as a proper meal with adequate fiber and protein, both of which keep you full for longer.

Deep frying also introduces acrylamide into your fries, a compound that can increase your risk of cancer.6 So, you increase cancer risk and end up consuming a lot of empty calories and going over how many you burn, gaining weight instead of losing it. Not to mention, diets full of fried foods will wreak havoc on back pain due to the inflammatory response.

Eaten with Sugary Condiments

While you can eat French fries and lose weight, you need to be careful of what you dip them in, too. Ketchup is calorie-dense since it’s high in sugar and sugar rich diets correlate with higher abdominal fat levels, and might make you crave that sweet, sweet dessert!7

Even if you’re not dipping your fries in ketchup, there’s a reason doctors tell you ways to stop eating junk food! Other custom dipping sauces served with fast food are usually high in sugar, too, and almost none of them are suitable for your health.

Starchy and High Glycemic Index

The glycemic index (GI) indicates how much a food raises your blood sugar level and from 0-100, French fries have a GI of 75. Which means they spike blood sugar, triggering your pancreas to release insulin to metabolize it.8
This insulin release is a problem for weight loss, as your body only burns fat when your insulin levels drop to normal.9 Plus, insulin spikes also make you crave more food, so you’re likely to eat more after having a lot of fries.


French fries are generally extremely salty, meaning they contain a lot of sodium. Too much sodium means your body retains excess water and causes a rise in blood pressure.10 On top of being unhealthy, this makes your belly bloat and your face swell up, making you look as if you gained weight.

When people start dieting, water weight is the first thing they lose, and too much sodium prevents this weight loss! If you retain water and see the scale go up, not only can it make you look heavier, but you might also lose motivation for continuing your diet and exercise regimen.

You don’t have to suffer through these consequences of eating fries, though – try some healthy alternatives instead.

A medium serving of sweet potato French fries that were freshly salted.

French Fry Alternatives

You can eat French fries and lose weight, but there are a lot of healthier alternatives exist. Some of them include:

Air frying: Air frying uses a fraction of the oil that deep-frying does since you only have to apply a thin layer of fat, so you eat a lot fewer calories. A good air fryer can be a real lifesaver!

Sweet potato French fries: Instead of air frying regular potatoes, try cutting up sweet potatoes. Not only are they tasty, but they also contain more vitamins A and C than regular potatoes.

Substitute fries for a salad or rice: Next time you go out on a diet, order a salad or a lean meat like chicken with brown rice instead. Salads are made with beneficial vegetables and sometimes lean meat, giving you multiple essential vitamins and minerals. Brown rice is also more filling than fries and doesn’t have much sodium, so choose it over fries any day!

Share the fries: If you’re eating with friends or family, share a pack of fries instead of buying individual servings for everyone. This method reduces how many fries everyone eats, and you consume fewer calories!

Exercise to counterbalance fry consumption – Doing 40-60 minutes of cardio is an excellent way to offset the calories in French fries. If this is the motivation you need, eat a few fries and go for it!

You can certainly eat French fries and still lose weight! Eating French fries isn’t a sin, but you need to be careful how often and how many you eat. Whether it’s fries, cookies, or ice cream, nothing is off-limits in a well-balanced diet, and fries won’t stop weight loss if you practice portion control and eat less than you burn to lose weight.


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2Ivy J. L. (2004). Regulation of muscle glycogen repletion, muscle protein synthesis and repair following exercise. Journal of sports science & medicine, 3(3), 131–138. <>

3Ascherio, A., & Willett, W. C. (1997). Health effects of trans fatty acids. The American journal of clinical nutrition, 66(4 Suppl), 1006S–1010S. <>

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10Kojima, S., Inoue, I., Hirata, Y., Saito, F., Yoshida, K., Abe, H., Deguchi, F., Kawano, Y., Kimura, G., & Yoshimi, H. (1987). Effects of changes in dietary sodium intake and saline infusion on plasma atrial natriuretic peptide in hypertensive patients. Clinical and experimental hypertension. Part A, Theory and practice, 9(7), 1243–1258. <>

About the Author

Nathan Petitpas

Nathan has been a fitness enthusiast for the past 12 years and jumps between several types of training such as bodybuilding, powerlifting, cycling, gymnastics, and backcountry hiking. Due to the varying caloric needs of numerous sports, he has cycled between all types of diets and currently eats a whole food diet. In addition, Nathan lives with several injuries such as hip impingement, spondylolisthesis, and scoliosis, so he underwent self-rehabilitation and no longer lives with debilitating pain.