LDL cholesterol
Viscous soluble fibers can reduce LDL cholesterol by increasing bile-acid loss and changing cholesterol metabolism. Oat beta-glucan is one of the better-studied examples.
Satiety
Appetite effects are less consistent. Some fibers increase fullness in some settings, but “fiber = automatic appetite suppression” is too broad. Fiber type, dose, food form and the individual matter.
Practical food sources
- Oats and oat bran
- Barley
- Beans and lentils
- Psyllium-containing foods/products
- Fruit and vegetables as part of total fiber intake
Evidence notes
- Whitehead et al. meta-analysis: ≥3 g/day oat beta-glucan reduced LDL cholesterol by about 0.25 mmol/L in controlled trials. PubMed: https://pubmed.ncbi.nlm.nih.gov/25411276/
- Clark & Slavin systematic review: appetite effects vary substantially by fiber type; most acute fiber treatments did not significantly increase satiety. PubMed: https://pubmed.ncbi.nlm.nih.gov/23885994/