Yes, water chestnuts are completely safe to add to your low fodmap diet. The regular serving size should be between 100g to 142g.
What is the Safe Serving Size of Chestnuts in a Low Fodmap Diet?
According to the Monash University, a serving amount of 100g (or 10-11 raw chestnuts) and 0.5 cup of (142g) canned water chestnut is low fodmap and is considered acceptable for the greater number of IBS sufferers (Irritable bowel syndrome). [1]
Note: Canned water chestnuts are more widely accessible in the United States than raw water chestnuts.
Nutrient Values in Water Chestnuts
The USDA (U.S Department of Agriculture) provides the below nutritional values for 4 raw water chestnuts (36g). [2]
- Calories: 34.9
- Fat: 0.036g
- Sodium: 5.04mg
- Carbohydrates: 8.6g
- Fiber: 1.08g
- Sugars: 1.73g
- Protein: 0.504g
The USDA provides the following nutritional values for a 0.5 cup (142g) of canned water chestnuts sliced in water. [3]
- Calories: 49.7
- Fat: 0g
- Sodium: 8.52mg
- Carbohydrates: 9g
- Fiber: 1.99g
- Sugars: 0g
- Protein: 0g
You can get different brands of canned water chestnuts in the US, and their nutrient value might vary. [4]
What Makes Water Chestnuts Low Fodmap?
1. Fiber
2. Carbs
3. Fat
4. Protein
5. Vitamins and Minerals
1. Fiber
Water chestnuts are rich in fibers, which aids in the effective digestion of meals. They absorb the water, softening stools and making them easier to release.
They also include several vitamins and powerful antioxidants that are beneficial to your health. It can help manage cholesterol and sugar levels by keeping you filled and happy.
Note: Fiber content in water chestnuts makes up a total of 10% of the daily value.
2. Carbs
The carbohydrate content in a 0.5 cup serving of canned water chestnuts is around 9 g which shows that it is 3% of the daily value as described by the USDA. Starch and fibers make up the carbohydrates.
3. Fat
Water chestnuts do not have any fat.
4. Protein
Since raw water chestnuts offer a tiny quantity of protein, you will have to balance your everyday protein intake with other foods.
5. Vitamins and Minerals
A 0.5 cup of canned water chestnuts provides 2% of the daily value of vitamin C and 5% of iron requirements. They are rich in potassium, riboflavin, manganese, calcium, copper, and vitamin B6. They are particularly high in ferulic acid antioxidants, gallocatechin gallate, epicatechin gallate, and catechin gallate. [5] [6]
Things to Be Aware Of
The water chestnut plant can carry an inflammatory parasite known as fasciolopsiasis if consumed uncooked. Although canned water chestnuts carry minimal risk, so if you get them raw, make sure to properly clean them. [7] [8]
Varieties
Water chestnuts are vegetables (Eleocharis dulcis, also known as Chinese water chestnuts) that look similar to water caltrops (Trapa natans, also known as European water chestnuts) as they are not tuberous but rather nuts. These are also confused with Indian water chestnuts (also known as Singhara) that are also tuberous aquatic vegetables and are often used to make flour known as Singoda or Singhara flour. [9]
Conclusion
Now that you know the exact amount of water chestnuts you should be having on your low fodmap diet, it is important to get the maximum benefits from this vegetable. It can help people suffering from IBS or in general.

References