Question 1

Why does fibre matter?

Accepted Answer

Because it is the part of food your body **cannot digest**, and almost everything useful about it follows from that — including feeding the bacteria that can.

**What it is.** Plant carbohydrates that resist digestion by human enzymes, passing largely intact to the large intestine.

**The two broad types:**

**Soluble fibre** dissolves in water, forming a gel. It slows gastric emptying and glucose absorption, and **binds bile acids**, prompting the liver to draw on cholesterol to make more — the mechanism behind fibre's cholesterol-lowering effect. Found in oats, barley, pulses, apples and psyllium.

**Insoluble fibre** does not dissolve. It adds bulk and speeds transit through the gut. Found in wholegrains, bran, nuts and vegetable skins.

Most fibre-containing foods provide both.

**What it does:**

**Feeds the gut microbiome.** This is the mechanism receiving most attention now. Bacteria ferment fibre into **short-chain fatty acids** such as butyrate, which is the main fuel for the cells lining the colon and has anti-inflammatory effects. This is where **prebiotic** fibres come in — a prebiotic feeds existing bacteria, a probiotic introduces new ones.

**Regulates bowel function** in both directions, adding bulk and softening stool.

**Improves satiety** — fibre-rich foods are bulkier and slower to eat.

**Lowers cholesterol** via the bile acid mechanism.

**Blunts glucose response.**

**The evidence base is unusually strong.** Large meta-analyses have consistently associated higher fibre intake with lower rates of cardiovascular disease, type 2 diabetes, colorectal cancer and all-cause mortality, with a dose-response relationship. Among nutrition findings, this is one of the more robust.

**Most people fall well short.** UK recommendations are around **30g a day** for adults, and average intake is substantially below it. Fibre is one of the clearest gaps in typical Western diets.

**How to increase it:** wholegrain versions of what you already eat; pulses, which are exceptionally high; nuts and seeds; fruit and vegetables **with skins**; and potatoes eaten whole.

**Increase gradually and drink more water** — a sudden jump causes bloating and discomfort.

General information, not dietary advice.

Question 2

Why are some foods more filling than others?

Accepted Answer

Because satiety is driven by several mechanisms that have little to do with calories — and foods engineered to be easy to overeat are engineered to defeat each one of them. What actually produces

Question 3

What nutrients should I focus on when following a vegan diet?

Accepted Answer

Focusing on protein, vitamin B12, iron, calcium, omega-3 fatty acids, and vitamin D is crucial for a balanced vegan diet to prevent deficiencies.

Question 4

What does bioavailability mean in nutrition?

Accepted Answer

The proportion of a nutrient that is actually absorbed and available for use — as distinct from the amount present in the food. It is why the number on a label can substantially overstate what you

Question 5

What are the best protein sources for someone on a vegan diet?

Accepted Answer

A vegan diet can include various protein sources like legumes, nuts, seeds, and soy products. Combining these ensures a balanced intake of essential amino acids.

Question 6

What does the evidence say about saturated fat?

Accepted Answer

It is one of the most contested questions in nutrition, and the honest summary is that the confident positions on both sides overstate what the evidence supports. The established position. Major

Question 7

Is a calorie on a label the same as a calorie your body gets?

Accepted Answer

No — the label is a reasonable estimate, not a measurement of what you absorb, and several factors mean the number on the packet and the energy your body extracts differ. How labels are calculated.

Related Questions