Depletion and disruption of dietary fibre. Effects on satiety, plasma-glucose, and serum-insulin.
Level 2 - randomized trial
Individual randomized controlled crossover trial
PubMed 71495 · doi:10.1016/s0140-6736(77)90494-9
What was done
Ten normal subjects ingested three apple-based test meals (intact apples, fibre-disrupted purée, and fibre-free juice), each containing 60 g of available carbohydrate. Consumption speeds were evaluated, and when ingestion rates were equalized, satiety was assessed numerically alongside serial postprandial measurements of plasma glucose and serum insulin.
What was found
Fibre-free juice was consumed 11 times faster than intact apples and 4 times faster than purée. When ingestion rates were equalized, intact apples produced significantly greater satiety than purée, which was more satisfying than juice. Peak plasma glucose reached similar levels across all three meals; however, juice caused a striking rebound fall and purée a lesser rebound fall, whereas intact apples caused no rebound fall. Serum insulin rose to higher concentrations after juice and purée compared to intact apples (exact numerical values were not reported in the abstract).
Why it matters
This classic study demonstrated that food physical structure and intact dietary fibre regulate ingestion rate, satiety, and insulin secretion even when available carbohydrate amounts are identical.
Limits
The sample size was very small (n = 10) and restricted to healthy volunteers. Only acute postprandial responses to a single meal were measured rather than long-term metabolic outcomes, and specific numerical concentrations and confidence intervals were not provided in the abstract.
Cited by
- supports Consuming juiced fruit causes a rapid increase in blood sugar and an insulin response that leads to a subsequent blood sugar drop, driving hunger.