Apple Cider Vinegar: Does It Boost Your Metabolism?

study PMID: 34055150

Quick Summary: Researchers looked at whether taking apple cider vinegar (ACV) could help people burn more calories or use fat for fuel. They found that taking ACV for a short time didn't change how many calories people burned at rest or during exercise.

Does Apple Cider Vinegar Increase Metabolism?

This study aimed to see if taking apple cider vinegar could affect how your body uses energy. The researchers measured how many calories people burned while resting and exercising. They also looked at whether ACV changed the body's use of fat or carbohydrates for energy. The results showed that ACV didn't make a significant difference in any of these areas.

Study Details

Who was studied: 16 healthy adults.

How long: Participants took either ACV or a placebo (a drink without ACV) for 4 days.

What they took: Participants drank 30 ml of apple cider vinegar mixed in a lemon-flavored drink each day. The placebo group drank the same drink without ACV.

What This Means For You

This study suggests that taking apple cider vinegar for a short period (4 days) won't likely boost your metabolism or help you burn more fat. If you're looking for ways to increase your energy expenditure, this study doesn't support ACV as a solution.

Don't expect a quick fix: ACV might not be the magic bullet for weight loss or increased energy that some people claim.

Focus on proven methods: Consider other ways to boost your metabolism, like regular exercise and a balanced diet.

Study Limitations

It's important to remember that this study has some limitations:

Small group: The study only included 16 people, so the results might not apply to everyone.

Short time frame: The study lasted only 4 days. Longer-term effects of ACV are unknown.

Healthy individuals: The study focused on healthy adults. The results might be different for people with health conditions.

No blood tests: The study didn't measure blood sugar or other markers to understand how ACV might work.

Key Findings

This study found no significant effects of 4-day acetic acid (ACV) supplementation on resting energy expenditure (REE), exercise energy expenditure (EEE) at 40 W or 80 W, or substrate utilization (fat vs. carbohydrate oxidation) in healthy adults. Both REE and EEE outcomes showed minimal differences between ACV and placebo groups, with all p-values exceeding 0.05.

Study Design

The study employed a randomized, double-blind, crossover design with 16 healthy participants. Each underwent two 4-day supplementation periods (ACV vs. PLA) separated by a washout phase. Energy expenditure and substrate utilization were measured via indirect calorimetry at rest and during steady-state cycling exercises at 40 W and 80 W.

Dosage & Administration

Participants consumed 30 mL/day of apple cider vinegar (acetic acid concentration unspecified) mixed in 1 L of a non-nutritive lemon-flavored beverage. The placebo group received an identical drink without ACV. Supplementation duration was 4 days, with compliance monitored via returned container measurements.

Results & Efficacy

REE: No significant difference between ACV and PLA (p = 0.41).
EEE-40: No difference in energy expenditure (p = 0.55).
EEE-80: No significant difference (p = 0.26).
Substrate Utilization: Fat and carbohydrate oxidation rates were statistically similar between groups during rest and exercise (all p > 0.05).
Effect sizes and confidence intervals were not reported, as no meaningful differences were detected.

Limitations

Small Sample Size: n=16 limits statistical power and generalizability.
Short Duration: 4 days may be insufficient to observe metabolic adaptations.
Homogeneous Population: Results apply only to healthy adults; effects in metabolically diverse groups (e.g., overweight individuals) remain unknown.
Lack of Biomarkers: No measurements of blood glucose, insulin, or acetic acid absorption to explain mechanisms.
Exercise Intensity: Findings may not extend to higher-intensity or prolonged activity.

Clinical Relevance

For healthy adults, daily consumption of 30 mL ACV for 4 days does not appear to enhance energy expenditure or shift substrate utilization toward fat oxidation during rest or moderate-intensity exercise. These results suggest ACV may not support metabolic boosting or fat-burning claims in this context. However, the study does not address longer-term effects, higher doses, or potential benefits in other populations (e.g., those with insulin resistance). Users seeking metabolic support should consider evidence from larger, longer trials targeting specific health conditions.

Strengths: Rigorous crossover design minimized individual variability; indirect calorimetry ensured precise metabolic measurements.
Weaknesses: Limited sample size, duration, and lack of biochemical data weaken conclusions.

Takeaway: This trial does not support the use of ACV for acute improvements in energy metabolism in healthy individuals.