What Foods Cause Gas and Bloating? Common Culprits Explained

By KT Apps · Updated October 17, 2026

A note first

This article is general information, not medical or dietary advice. Foods affect people differently, and many of the foods listed here are healthy for most people. See a doctor promptly for severe or persistent abdominal pain, blood in your stool, unexplained weight loss, ongoing diarrhoea or vomiting, a fever, or a lasting change in bowel habits, and talk to a doctor or dietitian before cutting out whole food groups.

Where intestinal gas comes from

Gas in the gut has two main sources. The first is swallowed air, which comes from eating quickly, talking while eating, chewing gum, drinking through a straw and fizzy drinks. The second is fermentation: some carbohydrates are not fully digested in the small intestine, so they reach the large intestine, where bacteria break them down and release gases.

Fermentation explains why certain foods have such a reputation. The more of these hard-to-digest carbohydrates a food contains, and the more of it you eat, the more gas tends to follow, often several hours later.

Common culprits

• Beans, lentils and chickpeas, which contain carbohydrates that reach the large intestine largely undigested.
• Onions and garlic, which are used in so many dishes that they are easy to overlook.
• Cabbage-family vegetables such as broccoli, cauliflower, cabbage and Brussels sprouts.
• Wheat and rye, especially in large portions.
• Milk and other dairy foods for people who do not digest lactose well.
• Some fruits, such as apples, pears and watermelon, and fruit juices.
• Sugar alcohols used as sweeteners, such as sorbitol and xylitol, found in some sugar-free sweets and gum.
• Fizzy drinks and beer, which add gas directly.
• A sudden big increase in fibre, even from healthy foods.

None of these will affect everyone the same way. The point of a list like this is to know what to look at first, not to avoid all of them.

What FODMAPs are

FODMAP stands for fermentable oligosaccharides, disaccharides, monosaccharides and polyols: a group of short-chain carbohydrates that some people absorb poorly. They draw water into the gut and are fermented by bacteria, which can cause gas and bloating, particularly in people with a sensitive gut.

Foods are often grouped as higher or lower in FODMAPs. Examples often given as higher include onions, garlic, beans, wheat, apples, pears and milk. Examples often given as lower include rice, oats, potatoes, carrots, cucumber, oranges, strawberries and lactose-free milk. Portion size matters, and lists differ slightly between sources.

A low FODMAP diet is a structured, temporary process of cutting back and then reintroducing foods to find personal triggers. It is best done with a doctor or dietitian, because a long-term restrictive diet can miss out on important nutrients.

Everyday habits that may help

• Eat slowly and chew well, which reduces swallowed air.
• Cut down on fizzy drinks and chewing gum.
• Increase fibre gradually rather than all at once.
• Keep active; regular movement helps the gut move things along.
• Drink enough water through the day.
• Notice stress, which affects how the gut works for many people.

Finding your own triggers

Because foods affect people so differently, the most useful list is your own. Recording meals and symptoms for a few weeks shows which foods actually come before your discomfort, and which ones never seem to. For how to do that well, see how to keep a food and symptom diary.

Finding patterns in GasLog

GasLog is set up to test this list against your own experience:

1. Log each meal with the Meal button, choosing foods from categories such as Beans, Vegetables, Dairy, Fruits and Drinks, or typing your own.
2. Log symptoms with Condition and gas episodes with Gas, using the 1 to 5 scales.
3. After a couple of weeks, open the Analysis tab. It lists the foods most often followed by gas or symptoms within 24 hours over the last 30 days, and gentler foods with the lowest rates.
4. Read the Tips tab for general habits and examples of low and high FODMAP foods.

The analysis is a simple count of your own entries, not a diagnosis, and it cannot tell apart foods eaten in the same meal. GasLog works in your browser with no account; the iPhone and Android apps add a daily reminder.

Frequently asked questions