The Claim

In adult women, a low-glycemic-index diet increases fat oxidation at fasted rest to 45% ± 4% of total oxidative requirements, compared to 28% ± 5% on a high-glycemic-index diet, indicating that glycemic index modulates substrate utilization during fasting.

Source: Low-Versus High-Glycemic Index Diets in Women: Effects on Caloric Requirement, Substrate Utilization and Insulin Sensitivity

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
53score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Quantitative
1 study reviewed
In plain English

In adult women, eating a low-glycemic-index diet results in 45% ± 4% of energy being derived from fat oxidation during fasting, while a high-glycemic-index diet results in 28% ± 5% fat oxidation during fasting.

See the scientific wording

In adult women, a low-glycemic-index diet increases fat oxidation at fasted rest to 45% ± 4% of total oxidative requirements, compared to 28% ± 5% on a high-glycemic-index diet, indicating that glycemic index modulates substrate utilization during fasting.

Why this might work

When a person eats carbohydrates that release sugar slowly, their body releases less insulin after meals. Lower insulin levels allow fat cells to break down stored fat more freely, releasing fatty acids into the blood. These fatty acids travel to muscles and the liver, where they are burned for energy, especially when the body is at rest and hasn't eaten recently. This shifts the body's fuel use from sugar to fat, increasing the percentage of energy coming from fat during fasting.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: Low-Versus High-Glycemic Index Diets in Women: Effects on Caloric Requirement, Substrate Utilization and Insulin Sensitivity

    When women ate carbs that don't spike blood sugar quickly, their bodies burned more fat while resting after fasting—45% of their energy came from fat, compared to only 28% when they ate carbs that spike blood sugar fast.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

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