Role of substrate utilization and thermogenesis on body-weight control with particular reference to alcohol.
Level 5 - mechanism / opinion, no new human data
Narrative review of metabolic mechanisms without systematic search methodology
PubMed 11115785 · doi:10.1017/s0029665100000744
What was done
This narrative review synthesized evidence on the caloric yield, diet-induced thermogenesis, and substrate oxidation pathways of alcohol (ethanol) compared to carbohydrates and fats, assessing its influence on body weight regulation and fat storage.
What was found
Ethanol provides 29.7 kJ (7.1 kcal)/g or 23.4 kJ (5.6 kcal)/ml of fuel energy without essential nutrients. It produces an average thermogenic effect of 15% of its metabolizable value, resulting in lower net efficiency of energy utilization than fat or carbohydrates. Ethanol oxidation is obligatory, prioritised, and does not depend on the dose ingested. It shifts postprandial substrate utilization by decreasing fat oxidation via a non-insulin-mediated pathway and inhibits peripheral lipolysis through acetate production. Isoenergetic replacement of carbohydrates or fat with ethanol under normoenergetic conditions does not produce greater body fat storage.
Why it matters
The review clarifies that while alcohol acutely halts fat oxidation to prioritize ethanol clearance, its elevated thermogenic cost prevents disproportionate fat accumulation when total energy intake remains balanced.
Limits
The abstract outlines a narrative review rather than a systematic synthesis or primary human trial, providing no trial numbers or sample sizes. The authors specifically note a lack of experimental data on how alcohol consumption affects spontaneous physical activity.
Cited by
- supports Alcohol provides approximately 7 calories per gram of energy.