GLOSSARY

Non-Viscous Fiber creates little viscosity under the conditions of use. This describes gel and flow behaviour, not lack of importance, non-fermentability or absence of physiological effects.

Solubility, viscosity and fermentability are separate properties. Inulin can be soluble, low-viscosity and readily fermented; psyllium forms gels but is generally less fermented. Two ingredients described as soluble fibre therefore need not produce the same intestinal consistency, gas production or post-meal response.

Dietary fibre comprises components resistant to small-intestinal digestion and absorption, with definitions and analytical methods differing between authorities. Some definitions admit isolated or manufactured carbohydrates when beneficial physiological effects are demonstrated. Being non-digestible alone does not automatically qualify an ingredient as declared fibre in every labelling framework.

Inulin can be added to yoghurt without much thickening and still be fermentable. Thin texture does not establish low fibre, nor does low viscosity guarantee no bloating. Athletes need the added amount and their tolerance, particularly when considering an unfamiliar product near competition.

Large-intestinal microbes can convert some remaining carbohydrates into short-chain fatty acids and gases. This differs from direct glucose absorption and cannot be treated as equivalent rapid running fuel. Both the amount and rate of fermentation depend on the substrate's structure and the individual's microbial community.

Fermentation alone does not establish prebiotic status: selective utilisation by host microorganisms and a health benefit must be demonstrated. Increasing one bacterial group alone does not prove improved sport performance either. Evidence depends on ingredient, dose, studied population and actual outcome, rather than every fibre-containing product having the same effect.

Increasing fibre works best with tolerable amounts, time to adapt and appropriate fluids. Suddenly adding several high-fibre products can cause bloating or altered bowel habits. The aim is a suitable combination of foods and timing; discomfort after one large serving is no reason to exclude every fibre source permanently.

Fibre and plant foods contribute to overall diet quality, but choices can change temporarily around competition. An athlete prone to digestive discomfort may choose a lower-fibre meal before intense exercise and eat higher-fibre foods at another time. Adjusting timing differs from excluding a food group in the long term.