Is fibremaxxing healthy? Harvard doc breaks down the pros and cons

After months of obsession over high-protein diets, the wellness spotlight is shifting. This time, it’s all about fibre — a nutritional trend that has real merit. But, like most wellness fads, it is not all good news. Dr Saurabh Sethi, a gastroenterologist trained at Stanford and Harvard, thinks fibremaxxing is great, but also cautions against the common mistakes people make while jumping on this bandwagon.

Though people today are aware of the importance of having adequate protein in their diets, most turn a blind eye to fibre. The California-based doctor is absolutely thrilled that fibre is finally getting the attention it deserves. “Fibremaxxing is exploding online. And honestly? As a gastroenterologist, I’m glad people are finally paying attention to fibre. Because most adults are severely under-consuming it,” Dr Sethi said in a recent newsletter.

However, just like most nutrition trends, there are also pitfalls that most people hardly realise. “More is not always better,” the doctor shares.

Turns out, your mum was right about eating more whole plant foods. They’re your primary source of fibre — a nutrient your body simply can’t do without. Dr Sethi explains the benefits of fibre.
Better gut health: Fibre feeds beneficial gut bacteria, helping support digestion, bowel regularity, and microbiome diversity.
Improved fullness: High-fibre meals can help people feel fuller for longer, which may reduce overeating and constant snacking.
Stabilises blood sugar: Fibre slows digestion and may reduce rapid glucose spikes after meals.
Better cholesterol support: Certain fibres, especially soluble fibres, can help support healthy cholesterol levels.

The long-term health implications are equally compelling. Dr Sethi emphasises that higher fibre intake is associated with lower risks of the following conditions.

• Colon cancer
• Cardiovascular disease
• Fatty liver disease
• Metabolic dysfunction
• Cons of fibremaxxing

​While fibre is essential for your body, Dr Sethi also cautions against the mistakes most people make. The most common mistake? Increasing fibre too quickly. Adding too much fibre, too fast, can lead to bloating. “This is the biggest mistake I see. If you suddenly jump from 10g to 40g daily, your gut will notice. Gas, bloating, abdominal discomfort, and changes in bowel habits are common,” he explains.

Similarly, in the pursuit of getting adequate fibre, most people go overboard on raw foods, which can worsen the condition. “Huge salads, raw cruciferous vegetables, and excessive fibre bars can worsen symptoms in sensitive guts,” the doctor explains. This becomes problematic, especially in people with conditions like irritable bowel syndrome (IBS), chronic bloating, or SIBO tendencies. Also, taking fibre without water can backfire. “Fibre needs hydration. Without enough fluids, constipation can actually worsen,” the doctor adds.

Dr Sethi also warns against processed ‘high-fibre’ marketing. You might find products promising to give you more fibre in the aisles of your grocery store, but you should be aware of what you are actually buying. “Many processed snacks market themselves as ‘high fibre’ while still being ultra-processed foods. Adding isolated fibre to junk food doesn’t automatically make it healthy,” the doctor reminds.

Dr Sethi warns against aggressively ‘fibremaxxing’. Rather than chasing record fibre numbers, he suggests a practical approach. Here are some recommendations from the gastroenterologist.

• Increasing fibre gradually
• Prioritising whole foods
• Eating a diversity of plant foods
  
• Staying hydrated
• Paying attention to your own symptoms
  

The Harvard-trained doctor also suggested some foods that are excellent sources of fibre.
Berries
Chia seeds
Lentils
Beans
Oats
Pistachios
Vegetables
Slightly green bananas

Fibre is essential for your body, and according to Dr Sethi, most people need more fibre. “But your gut is not a competition. The goal is not to eat as much fibre as possible. The goal is to find the amount your body consistently tolerates and benefits from. Trust your gut,” he says.