Weight, muscle & metabolism

Constipated Since You Started Eating Less? Here's Why

It's one of the most common side effects of cutting back, and one of the least talked about. The fix is usually simple.

A plate of fresh vegetables and fruit beside a breakfast shake

You've cut back on portions, swapped the toast for eggs, maybe started a shake. The scales are moving. And now things have slowed down in a less welcome way.

You're not imagining it, and it's very common. Here's why it happens and how to get back to normal.

Why eating less can make you constipated

Less food means less bulk. Smaller meals simply give your bowel less to work with.

Cutting carbs often cuts fibre. Bread, cereal and pasta are where many of us get most of our fibre. Take them out without replacing them, and fibre intake can halve.

High protein can crowd out plants. Protein is the right focus after 40, but a plate of chicken and eggs with no vegetables leaves fibre behind.

You're probably drinking less than you think. Fibre needs water to work, and summer heat raises how much you need.

Perimenopause plays a part. Hormonal changes in midlife can slow how quickly food moves through the gut, so you may notice this more now than you would have at 30.

What helps

  1. Bring fibre back, gradually. Aim for 25 g a day, adding 3–5 g a week. Vegetables, legumes, wholegrains, fruit with the skin on, nuts and seeds. How to reach 25 g a day →
  2. Drink more water as fibre goes up. Especially on hot days or if you exercise.
  3. Try two green kiwifruit a day. There's good evidence they help with regularity. Prunes are another option.
  4. Keep moving. A daily walk helps your gut keep moving too.
  5. Don't ignore the urge, and give yourself unrushed time in the morning.
  6. Check your supplements. Iron and some other supplements and medicines can cause constipation. Ask your pharmacist.

When to see your GP

See your GP if constipation lasts more than a few weeks, or straight away if you notice blood in your stool, unexplained weight loss, ongoing tummy pain, or a lasting change in your bowel habits. These are worth checking, whatever your age.

Australians aged 45 to 74 are also eligible for free bowel cancer screening.

Where MyPause fits

If you're struggling to get enough fibre while eating less, a supplement can close the gap.

Gentle Fibre Support gives you 3.6 g of fibre per 5 g sachet, from resistant starch, partially hydrolysed guar gum (PHGG) and acacia gum. These ferment more slowly than fibres like inulin, which is why many people find them gentler. It's unflavoured and mixes into water, a smoothie or your shake. It's designed to support your everyday fibre intake.

Gentle Fibre Support is a source of dietary fibre. Dietary fibre contributes to regular laxation.

Not suitable for infants, children or women who are pregnant or breastfeeding.

Shop Gentle Fibre Support →

Using the Slim Down Shake? Each serve already gives you 7 g of fibre. Adding a sachet of Gentle Fibre takes one glass past 10 g. Shop the Slim Down Shake →

Related support
Gentle Fibre Support

Gentle Fibre Support

3.6 g of slow-fermenting fibre per sachet from resistant starch, PHGG and acacia gum. Unflavoured, so it mixes into water, a smoothie or your shake.

Explore Gentle Fibre Support

Always read the label and follow the directions for use. If symptoms persist, talk to your health professional.

Common questions

Is it normal to be constipated when losing weight?

Yes, it's common, usually because you're eating less fibre and less food overall. Building fibre and water back up gradually usually sorts it out.

Can a high-protein diet cause constipation?

It can if protein replaces vegetables, legumes and wholegrains. Keep half your plate as vegetables and you get both.

How long does it take for more fibre to help?

Most people notice a difference within a few days to a couple of weeks. Increase slowly to avoid wind and discomfort.

Should I take a laxative?

Talk to your pharmacist or GP before using laxatives regularly. Fibre, water and movement are the first steps.

References

1. National Health and Medical Research Council. Nutrient Reference Values for Australia and New Zealand: dietary fibre. eatforhealth.gov.au

2. National Bowel Cancer Screening Program, Department of Health.

This article is general information and does not replace advice from your health professional.

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