Dr Nick Fuller
Leading Obesity Expert at the University of Sydney and founder of Interval Weight Loss.
We’ve all been there: you swap out takeaway for lentils, pile your plate with broccoli, and sip on a ‘gut-friendly’ smoothie, only to feel like you’re carrying a beach ball in your stomach. If you’ve ever wondered why you feel bloated after eating healthy, you’re not alone.
In fact, research shows that up to 25% of adults experience bloating regularly, and it’s particularly common when increasing fibre or eating certain plant-based foods. Evidence suggests that diets high in FODMAPs, or fermentable carbohydrates found in beans, whole grains, and some fruits, may trigger digestive symptoms in sensitive individuals, with bloating commonly reported. The silver lining? It’s usually temporary, and often just your gut adapting to healthier changes.
Let’s break down why this happens, which foods are the usual suspects, and what you can do to prevent it.
It may feel unfair that the foods meant to help you end up making you uncomfortable. But there’s science behind it. Many nutrient-packed foods are rich in fibre, resistant starches, or natural sugars that your gut bacteria ferment. Fermentation creates gas, which leads to that classic ‘balloon belly’ feeling.
Jumping from a low-fibre diet to one loaded with whole grains and veggies can shock your gut. Fibre is essential for digestive and heart health, but too much, too quickly, overwhelms your microbiome. Experts recommend 25–30g of fibre daily, but the body needs time to adapt. Paying attention to how often you should eat to lose weight can also help your body adjust more comfortably.
Veggies like broccoli, kale, and cauliflower are loaded with vitamins, antioxidants, and sulphur-rich compounds. The downside? They contain raffinose, a carbohydrate that ferments in the colon and produces gas.
Lentils, chickpeas, and kidney beans are protein-packed and heart-healthy, but also high in FODMAPs. These fermentable carbs travel undigested to the large intestine, where they’re broken down by bacteria and cause bloating.
Brown rice, oats, and whole wheat bread contain resistant starch, which resists digestion in the small intestine. While this boosts gut health long term, it can temporarily increase gas production.
Sugar-free protein bars, diet drinks, and ‘low-cal’ snacks often use sugar alcohols like sorbitol or xylitol. Since they’re not fully absorbed, they ferment in the gut, leading to gas and discomfort.
Raw veggies are nutrient-rich but tough to break down in bulk. A giant salad might seem virtuous, but too much at once strains digestion, causing bloating.
Bloating isn’t the only way your body can react to nutritious meals. A large UK survey of over 500 adults found that nearly 86% had experienced at least one gastrointestinal symptom in the past month, even though most did not have a diagnosed digestive disorder. This shows that even healthy diets can sometimes backfire if your gut is on the sensitive side.
Gas and flatulence – Caused by fermentation of extra fibre or FODMAPs, which gut bacteria break down into gas.
Abdominal cramps – Trapped gas stretches the intestinal walls, leading to pain and discomfort.
Loose stools or diarrhoea – A sudden fibre boost or sugar alcohols (like sorbitol in apples) can speed up gut transit.
Constipation – Too much fibre without enough water slows digestion, a common issue noted in fibre intervention studies.
Acid reflux – Triggered by foods like citrus, tomatoes, or even onions, which can relax the lower oesophageal sphincter.
Food intolerance reactions – Lactose or gluten sensitivities affect up to 70% of the population worldwide in some form, often causing bloating and discomfort.
While every gut is different, research suggests that certain foods are more likely to trigger gas. For example, cruciferous vegetables and legumes are rich in raffinose and other fermentable carbohydrates that gut bacteria love to feed on. This fermentation process is natural but can lead to noticeable bloating.
Broccoli – High in fibre and raffinose, which ferments in the gut.
Cauliflower – Another cruciferous veggie rich in gas-forming compounds.
Cabbage – Packed with nutrients but notorious for causing flatulence.
Kale – Nutrient-dense yet hard to digest raw in large amounts.
Lentils – Protein-rich legumes high in FODMAPs; one study showed legumes increase hydrogen gas production significantly.
Chickpeas – Contain galacto-oligosaccharides, which feed gut bacteria.
Beans – Infamous for producing hydrogen and methane gas—hence their reputation.
Onions – Rich in fructans, a FODMAP linked to IBS symptoms.
Garlic – Another fructan-heavy food that may cause digestive distress.
Apples – Contain sorbitol and fibre, both linked to bloating.
Pears – High in fructose and sorbitol, which ferment in the gut.
Whole wheat bread – Fibre-rich but harder to digest if eaten in big portions.
Not all bloating is diet-related. Sometimes, it’s about how and when you eat. Factors like lifestyle, hormones, and gut health all play a role.
Overeating – Stretching your stomach leads to pressure and gas buildup.
Eating too quickly – Makes you swallow more air, which directly causes bloating.
Drinking carbonated beverages – Adds extra gas into your system.
High salt intake – Triggers water retention and a puffy belly; Australians consume about double the WHO’s recommended daily salt intake.
Hormonal changes – Bloating often increases during menstruation due to fluid shifts and hormonal fluctuations.
Constipation – Trapped stool increases pressure in the intestines.
Irritable bowel syndrome (IBS) – It affects 10-20% of the global population, and bloating is one of its hallmark symptoms.
Gastrointestinal infections – Temporary gut issues can cause gas, cramping and discomfort until the infection clears.
If you’re unsure whether what you’re experiencing is just bloating or actual weight gain, see our guide on how to know if you’re bloated or gaining weight.
You don’t have to ditch nutritious foods. Just work with your gut to find balance. The key is making small adjustments that support digestion rather than overwhelm it.
Fibre is amazing for gut health, but a sudden increase can overload your digestive system. Slowly increasing your fibre intake over weeks instead of days gives your gut bacteria time to adapt. This reduces the risk of gas, cramping and uncomfortable bloating after meals.
Beans are packed with plant-based protein and fibre, but they also contain fermentable carbs that can be tough on digestion. Soaking them overnight and cooking them thoroughly breaks down some of these compounds. As a result, beans become gentler on your gut and less likely to cause excess gas.
Sparkling water, soft drinks and other fizzy beverages introduce extra carbon dioxide into your digestive system. This gas has to go somewhere, and often, it leads to bloating and discomfort. Swapping fizzy drinks for still water, herbal tea or infused water can reduce that trapped, gassy feeling.
The way you eat can be just as important as what you eat. Eating smaller portions and chewing your food thoroughly helps your digestive system break it down more efficiently. Plus, eating slowly means you swallow less air, which also cuts down on bloating.
Some healthy foods, like apples, onions and beans, are high in FODMAPs, fermentable carbs that can trigger bloating in sensitive people. Research shows that a low-FODMAP diet reduces bloating in people with IBS. Swapping in lower-FODMAP options, like zucchini, berries or rice, may make a big difference if you notice certain foods set you off.
Water keeps fibre moving through your digestive system, preventing constipation and reducing pressure in the gut. Staying active also stimulates digestion, helping your body process food more smoothly. Even light exercise, like aerobic exercise, walking or yoga, can help release trapped gas and ease that bloated feeling.
Feeling bloated after eating healthy doesn’t mean you’re doing anything wrong. It often just signals your gut is adjusting to the change.
Whether it’s fibre overload, FODMAP-rich veggies, or too much raw salad, these causes are usually harmless. With small tweaks, like cooking veggies, introducing fibre gradually, and eating more mindfully, you can enjoy all the benefits of healthy eating without the dreaded bloat.
Dr Nick Fuller is the founder of Interval Weight Loss and is a leading obesity expert at the University of Sydney with a Ph.D. in Obesity Treatment. Dr Fuller is also the author of three best-selling books and his work been published in top ranked journals in the medical field, including JAMA, Lancet and American Journal of Clinical Nutrition.