Sodium propionate, energy use and fat burning in people
What it found
In 18 healthy adults, a single dose of sodium propionate raised resting energy use and fat burning slightly, without changing blood sugar or insulin.
The authors say longer studies are needed to see if this matters for weight over time.
What they found
Studies in people
Energy use
Resting energy expenditure was higher after propionate than after the control, by an average of 0.045 kcal/min. The authors say this increase was independent of changes in glucose and insulin.
Fat burning
Whole-body lipid oxidation rates were higher after propionate, by an average of 0.012 g/min. The respiratory exchange ratio was lower in the propionate trial (0.85 vs 0.88).
Blood sugar and insulin
There were no differences between trials in circulating glucose or insulin levels. The authors say the effects on energy use were not related to these.
Propionate in blood
Blood propionate levels were higher in the propionate trial, with values significantly raised at 180 minutes compared with control (5.25 vs 3.04 μmol/L). There were no differences in acetate or butyrate levels.
Gut hormone PYY
PYY levels were raised after propionate at 180 minutes compared with control (56.9 vs 33.6 pmol/L). The authors say this may have modified energy intake if it had been measured.
Heart rate and blood pressure
There were no significant differences in heart rate or mean arterial blood pressure between the two visits.
Hunger and nausea
Volunteers reported no difference in subjective hunger between trials, but nausea was significantly higher in the propionate trial.
What the authors conclude
“In summary, the present study provides the first direct evidence that acute oral administration of sodium propionate stimulates REE and whole‐body lipid oxidation in humans, thus corroborating the outcome of investigations conducted in mice.”
Also in their conclusions
- They say the study provides the first direct evidence that acute oral sodium propionate stimulates resting energy expenditure and whole-body lipid oxidation in humans, corroborating mouse studies.
- They state that future studies are warranted to determine whether the acute effects translate into positive improvements in long-term energy balance in humans.
- They advise that long-term studies are needed to demonstrate the same benefits to body weight and glucose homeostasis seen in mice.
How it was done
The authors note that propionate, a short-chain fatty acid made by gut bacteria from dietary fibre, has been suggested to help control energy metabolism. Previous work in mice found that oral propionate raised resting energy expenditure by promoting fat oxidation, but there was little evidence in humans.
Eighteen healthy volunteers (9 women and 9 men, average age 25, average BMI 24.1) completed two study visits after an overnight fast, in random order. Over 180 minutes they took tablets containing a total of 6845 mg sodium propionate or 4164 mg sodium chloride. Resting energy expenditure and substrate oxidation were measured by indirect calorimetry.
What it can’t tell you
- This was a single dose in healthy fasted adults, so it cannot show what happens with long-term use or in other groups.
- The study did not measure energy intake, so it cannot show the full effect on energy balance.
- The authors note that the increase in energy use would need to last more than 3.5 hours to achieve a negative energy balance.
Who paid
- Funding
- Funded by Medical Research Council; Biotechnology and Biological Sciences Research Council (from the PubMed record).
- Conflicts
- The authors declare no conflicts of interest.
- Authors work at
- Imperial College London, UK; Scottish Universities Environmental Research Centre, UK
The paper
- Title
- Acute oral sodium propionate supplementation raises resting energy expenditure and lipid oxidation in fasted humans
- Type
- Randomised controlled trial
- Evidence
- Studies in people
- Summarised from
- Full text
- Cite
- Chambers ES, Byrne CS, Aspey K, et al (2018). Acute oral sodium propionate supplementation raises resting energy expenditure and lipid oxidation in fasted humans. Diabetes, obesity & metabolism. doi:10.1111/dom.13159Free full textPubMed 29134744DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error