Are Tomatoes Low FODMAP? Serving Notes, Sauce & Sun-Dried Rules

Short answer

Yes — most fresh tomatoes are Low FODMAP at the low-FODMAP serves. Common tomatoes (75 g / about half a medium tomato), cherry tomatoes (5 fruits / 75 g), and roma tomatoes (65 g) are all rated Low. Sun-dried tomatoes and tomato paste become High FODMAP quickly because water is removed and fructans concentrate. Canned tomatoes are safe at ½ cup (100 g) per serve.

Monash portion chart for tomatoes

Ingredient watch: many jarred pasta sauces contain onion, garlic, or "natural flavours" on top of the tomato — that's usually what causes symptoms, not the tomato itself. Always check the label.

Why concentrated tomato products are risky

Tomatoes contain a small amount of fructans. In fresh fruit, water dilutes them and portions stay safe. But when tomatoes are dried, reduced, or concentrated (paste, sun-dried, canned soup), the fructans stack up fast. A single tablespoon of tomato paste = the fructans of about 4 fresh tomatoes.

This is a classic case of FODMAP stacking — same food, different form, very different tolerance. See our full FODMAP Stacking Guide for the science.

Safe ways to eat tomatoes on a Low FODMAP diet

1. Fresh in salads — 5 cherry tomatoes or ½ common tomato per serve.
2. Homemade pasta sauce — use ½ cup canned tomatoes + garlic-infused oil + spring onion greens.
3. Bruschetta — dice ½ tomato, add basil and infused oil, serve on Low FODMAP bread.
4. Roasted with chicken — halve cherry tomatoes and roast alongside our One Pan Chicken and Rice.

High → Low FODMAP swap chart

Common questions

Are cherry tomatoes Low FODMAP?
Yes — 5 cherry tomatoes (75 g) is Low. Twelve or more becomes High.

Is tomato ketchup Low FODMAP?
It depends. Monash rates 2 sachets (13 g each) of common tomato ketchup as Low, but many brands add onion powder or garlic. Always check the label.

Can I eat tomato soup?
Homemade with ½ cup canned tomatoes per bowl, garlic-infused oil, and lactose-free cream — yes. Store-bought is usually High because of onion.

Are green (unripe) tomatoes Low FODMAP?
Monash hasn't tested green tomatoes specifically. Stick to red, ripe fruit at tested serves.

Bottom line

Fresh tomatoes are one of the easier "Low FODMAP with a caveat" foods — stay under ½ common tomato or 5 cherry tomatoes per serve, and treat concentrated forms (paste, sun-dried, jarred sauces) with respect. Pair with our Low FODMAP Vegetables Guide to plan a full safe plate.

Sources

• Monash University FODMAP App — tomato portion database
• Monash Blog: tomato-based sauces — fructans concentration in paste and passata

Written by the LowFODMAPRecipe.com Editorial Team. Educational content, not medical advice. Individual tolerance and serving size can vary — work with a registered dietitian or doctor for personal guidance.

Practical Low FODMAP Takeaways for Are Tomatoes Low FODMAP? Monash Portions, Sauce & Sun-Dried Rules

When using this guide, treat serving size as the most important detail. A food can be low FODMAP in one portion and become higher risk when the amount doubles or when it is combined with several similar ingredients in the same meal. For people with IBS, that cumulative effect is often the difference between a comfortable meal and symptoms later in the day.

A helpful approach is to pair this information with a simple food and symptom note. Write down what you ate, the portion, the time of day, stress level, and any symptoms over the next 24 hours. Patterns are usually more useful than one isolated reaction, especially because sleep, hormones, illness, caffeine, alcohol, and meal size can all affect digestion.

If you are in the elimination phase, keep meals simple and avoid testing several questionable foods at once. If you are in reintroduction, test one FODMAP group at a time with a structured serving ladder. That makes it easier to learn your personal tolerance instead of avoiding more foods than necessary.

For more planning support, use the FODMAP Food Checker before adding a new ingredient, the Ingredient Swap Finder when a recipe includes onion, garlic, wheat, lactose, or high-fructose sweeteners, and the Recipe Converter when you want to adapt a favorite meal. You can also browse low FODMAP recipes, breakfast ideas, dinner recipes, and IBS-friendly recipes to build a more varied weekly plan.

Medical disclaimer: This article is for general education only and is not a substitute for medical care. If you have ongoing digestive symptoms, unexplained weight loss, bleeding, fever, anemia, or severe pain, speak with a qualified healthcare professional. For personalized low FODMAP guidance, work with a registered dietitian familiar with IBS and FODMAP reintroduction.