Is Catsup Low FODMAP? What IBS Sufferers Need to Know
Yes, catsup is generally low FODMAP in small servings. A standard serving of one tablespoon (about 20 grams) falls within the low FODMAP range according to Monash University guidelines. However, not all catsup is created equal — certain ingredients commonly found in commercial catsup can trigger symptoms for people with IBS. Here is exactly what to watch for and which brands are safest.
Why Catsup Can Be Low FODMAP
Tomatoes themselves are low FODMAP. Vinegar is low FODMAP. Salt and most spices are low FODMAP. The basic building blocks of catsup are all safe for a low FODMAP diet, which is why a tablespoon or two of standard catsup is generally well-tolerated by most people following the elimination phase.
The problems arise from specific added ingredients that some brands include in their formulas.
Ingredients That Make Catsup High FODMAP
Three common catsup ingredients can push a serving into high FODMAP territory:
- High fructose corn syrup (HFCS) — Excess fructose is a high FODMAP sugar. HFCS contains more fructose than glucose, which can cause malabsorption and trigger symptoms like bloating, gas, and diarrhea. Many mainstream catsup brands use HFCS as their primary sweetener.
- Onion powder — Onion is one of the highest FODMAP foods due to its fructan content. Even small amounts of onion powder can be problematic for sensitive individuals. Unfortunately, onion powder appears in the ingredient lists of most commercial catsup brands.
- Garlic powder — Like onion, garlic is high in fructans and is a common IBS trigger. While less common in catsup than onion powder, some brands include it.
The good news is that the amounts of onion powder in a single tablespoon of catsup are typically very small. Monash University has tested standard ketchup and found that a one-tablespoon serving remains in the low FODMAP green zone. Problems are more likely to occur if you use larger servings — say, three or four tablespoons — where those trace amounts of onion powder and HFCS accumulate.
Low FODMAP Catsup Brands: Safe vs Risky
| Brand | Sweetener | Onion/Garlic | FODMAP Rating (1 tbsp) |
|---|---|---|---|
| Simply Heinz | Sugar | Onion powder | Safer choice |
| Heinz Original | HFCS | Onion powder | OK in small amounts |
| Primal Kitchen | No added sugar | No onion/garlic | Best choice |
| Hunt’s | Sugar | Onion powder | Safer choice |
| French’s | Sugar | Onion powder | Safer choice |
| Store brand (generic) | Often HFCS | Varies | Check the label |
Tips for Eating Catsup on a Low FODMAP Diet
- Stick to one tablespoon per sitting. This is the tested safe serving size. Going beyond two tablespoons increases your FODMAP load significantly.
- Choose brands sweetened with sugar instead of HFCS. Sugar (sucrose) is an equal mix of fructose and glucose, which is easier for your gut to absorb than the excess fructose in HFCS.
- If you are highly sensitive to onion, try Primal Kitchen. It is one of the few commercial catsup brands that contains no onion or garlic powder. It uses organic tomatoes, organic balsamic vinegar, and no added sugar.
- Consider making your own. A simple homemade catsup with tomato paste, vinegar, sugar, salt, and spices — minus onion and garlic — gives you complete control over FODMAP content.
- Stack with caution. If your meal already contains other moderate FODMAP foods, even a safe serving of catsup could push you over your threshold. Track your total FODMAP load across the entire meal.
The Bottom Line
Catsup is low FODMAP at one tablespoon, and most people with IBS can enjoy it without issues at that serving size. To minimize risk, choose a brand made with sugar instead of HFCS, and if onion is a known trigger for you, opt for Primal Kitchen or a homemade version. For more on what is in your catsup and how it affects your health, see our guides on whether catsup is gluten free and whether catsup is healthy.