What is the safe serving size for tomatoes?

For common tomatoes, the safe low FODMAP serving is ½ medium tomato (65g). For cherry tomatoes, stick to 5 medium tomatoes (45g) to stay low FODMAP.

Are canned tomatoes low FODMAP?

Yes, canned Roma/plum tomatoes are low FODMAP at ½ cup (100g) and remain moderate at 1 cup. They're a better choice than fresh cherry tomatoes.

Why are cherry tomatoes higher in FODMAPs?

Cherry tomatoes have a higher concentration of fructose compared to regular tomatoes, making them high FODMAP even at smaller serving sizes.

Is Tomatoes Low FODMAP?

Q: Are tomatoes low FODMAP?

It depends on the type and serving size. Common tomatoes are moderate FODMAP at ½ medium (65g), while cherry tomatoes are high FODMAP at just 5 medium. Roma tomatoes and canned tomatoes vary in their FODMAP content.

✓ Safe Serving	½ medium common tomato (65g)
✗ High FODMAP at	¾ medium common tomato (91g)
FODMAP Types	fructose (in larger servings)

Are Tomatoes Low FODMAP?

Tomatoes are moderate FODMAP, but it depends on the type. Common (round) tomatoes are moderate FODMAP at the standard ½ medium serving (65g) but can be consumed in smaller amounts with caution. Cherry tomatoes are high FODMAP at larger servings but low at 5 medium tomatoes (45g). Roma tomatoes and canned tomatoes have different FODMAP profiles that may be more suitable for some people.

The key to enjoying tomatoes on a low FODMAP diet is choosing the right type and measuring your portions carefully.

Safe Serving Sizes by Tomato Type

Common/Round Tomatoes (Fresh)

Serving	FODMAP Level	Weight
½ medium	Low	65g
½ medium	Moderate	75g
¾ medium	High	91g

Cherry Tomatoes (Fresh)

Serving	FODMAP Level	Count
5 medium	Low	45g
7 medium	Moderate	60g
9 medium	High	75g

Roma/Plum Tomatoes (Fresh)

Serving	FODMAP Level	Weight
⅓ medium	Low	48g
½ medium	Moderate	64g
¾ medium	High	75g

Canned Roma/Plum Tomatoes (with juice)

Serving	FODMAP Level	Volume
½ cup	Low	100g
1 cup	Moderate	182g
1¼ cups	High	244g

According to Monash University, canned tomatoes are generally better tolerated than fresh cherry tomatoes, making them a smart choice for cooking.

Why Do Tomatoes Contain FODMAPs?

Tomatoes contain fructose, a monosaccharide (simple sugar) that can be difficult for some people to absorb when present in excess of glucose. The concentration of fructose varies depending on:

Tomato variety - Cherry tomatoes have higher fructose concentrations than common or Roma tomatoes
Ripeness - Riper tomatoes may have slightly higher sugar content
Processing - Canned tomatoes appear to have lower FODMAP content than fresh

When fructose isn’t fully absorbed in the small intestine, it moves to the large intestine where gut bacteria ferment it. This fermentation produces gas and draws water into the bowel, causing symptoms like bloating, gas, abdominal pain, and diarrhea in people with IBS.

At smaller servings (½ medium common tomato or 5 cherry tomatoes), the amount of fructose is low enough that most people can tolerate it. As serving sizes increase, so does the fructose load and the likelihood of symptoms.

Tips for Eating Tomatoes on Low FODMAP

Choose the right type - Canned Roma tomatoes are your best bet for cooking, as they remain low FODMAP at ½ cup. Common tomatoes are moderate but manageable. Cherry tomatoes should be limited to 5 or fewer.
Measure carefully - Don’t eyeball tomato servings. Use a kitchen scale or count cherry tomatoes precisely, especially when you’re new to the diet.
Remove seeds and juice - Some people find that removing seeds and excess juice makes tomatoes easier to tolerate, though this doesn’t technically reduce FODMAP content.
Spread consumption throughout the day - Don’t eat tomatoes at multiple meals in one day to avoid FODMAP stacking.
Choose cooking over raw - While cooking doesn’t reduce FODMAPs, cooked tomatoes may be easier to digest for some people. Roasting or simmering can also concentrate flavor, so you may need less.
Watch sauces and condiments - Tomato sauce, ketchup, and pasta sauce often contain garlic and onion, which are high FODMAP. Look for low FODMAP certified products or make your own.
Check restaurant dishes - Salads, sandwiches, and burgers often come loaded with tomatoes. Ask for a specific amount or request them on the side.

Low FODMAP Alternatives

If you find you’re sensitive to tomatoes or want to save your FODMAP budget for other foods, consider these alternatives:

Red bell pepper - Roasted and pureed, red bell pepper can provide a similar color and slight sweetness in sauces. High FODMAP at 1 cup, but low at ½ cup.
Canned pumpkin - In soups and sauces, pumpkin can add body and a subtle sweetness. Low FODMAP at ⅓ cup.
Carrot puree - Cooked and blended carrots add color and natural sweetness to sauces. Low FODMAP at 1 small carrot.
Beetroot - Roasted beetroot can provide deep color and earthy sweetness in salads. Low FODMAP at ½ cup.
Sun-dried tomatoes - Interestingly, semi sun-dried tomatoes are moderate FODMAP at just 4 pieces (16g) but low at 3¼ pieces. Use sparingly for concentrated tomato flavor.

Recipes Using Tomatoes

Looking for ways to enjoy tomatoes safely on your low FODMAP diet? Here are some ideas:

Low FODMAP Pasta Sauce - Use ½ cup canned tomatoes per serving, simmered with garlic-infused olive oil (not garlic cloves), basil, oregano, and a pinch of sugar. The canned tomatoes allow for a generous serving.
Caprese Salad - Layer 5 cherry tomatoes or ½ medium sliced tomato with fresh mozzarella (check lactose content), fresh basil, and a drizzle of olive oil and balsamic vinegar.
BLT Sandwich - Add ½ medium sliced tomato to bacon, lettuce, and mayo on sourdough or gluten-free bread.
Tomato Cucumber Salad - Combine measured cherry tomatoes (5 max) with diced cucumber, fresh herbs, olive oil, and lemon juice.
Shakshuka - Make a low FODMAP version using ½ cup canned tomatoes per person, poaching eggs in the sauce with bell peppers, cumin, and paprika.
Tomato Soup - Puree canned tomatoes with low FODMAP vegetable broth, a splash of lactose-free cream, and fresh basil.
Salsa - Dice ½ medium common tomato and combine with cilantro, lime juice, jalapeño (if tolerated), and a pinch of salt. Perfect with low FODMAP corn chips.

Remember, everyone’s tolerance to tomatoes varies. During the elimination phase, stick to the safe serving sizes. During reintroduction, you can test fructose separately to determine your personal threshold for tomatoes and other fructose-containing foods.