Fibre
Fibre is carbohydrate that the small intestine cannot digest; it adds bulk and slows digestion, improves fullness and gut health, and yields far less energy per gram than other carbohydrate.
Fibre is the part of plant food that survives digestion more or less intact. It is counted as carbohydrate on a label but behaves nothing like starch or sugar once eaten.
Soluble and insoluble
Soluble fibre — in oats, barley, legumes, apples and psyllium — dissolves into a gel that slows gastric emptying and moderates the rise in blood glucose after a meal. Insoluble fibre — in wheat bran, whole grains and vegetable skins — adds bulk and speeds transit. Most foods contain both.
How much, and where people fall short
Common targets land around 25 to 30 g a day for adults, and most people in most countries eat well under that. A diet built on dal, whole grains, vegetables and fruit clears it without effort; one built on refined flour, meat and packaged food rarely does.
Why it matters for tracking
Two reasons. Fibre-rich foods are more filling per calorie than their energy content predicts, which makes a deficit easier to hold. And fibre affects how a food's calories are counted: labelling rules in different countries assign it different energy values, which is one of the small reasons two apps can disagree about the same packet.
Increase it gradually and with water. Doubling fibre overnight is uncomfortable and puts people off for months.
Sources
- 1.Dietary Reference Values — European Food Safety Authority
- 2.Dietary Guidelines for Americans, 2020–2025 — USDA and HHS
Related reading
- Fibre, fullness, and the macro nobody counts
Fibre is why two 500 kcal meals leave you in different states three hours later. How much you need, where to get it, and why it makes a deficit survivable.
- Carbs: how many you need and when it matters
Carbohydrate has no strict dietary requirement, which is not an argument for cutting it. What it is actually for, and how to decide your own intake.
- How to lose fat without quitting in three weeks
A deficit you barely notice, protein high enough to keep muscle, and a weekly trend to steer by. The whole method, and the parts people get wrong.
- Vegetarian protein worth the calories it costs
Ranked by calories per gram of protein, not by grams per 100 g. Which vegetarian sources are efficient, which are not, and how to build a 130 g day.