Eating a high-salt diet nearly doubled fasting levels of ghrelin, the hunger-stimulating peptide hormone, in healthy non-obese adults.
~85% increase in ghrelinFasting ghrelin rose from 172.9 to 320.7 pg/mL when healthy adults switched from a low-salt to a high-salt diet for just one week
What the researchers found
Fasting plasma ghrelin levels were significantly higher during a high-salt diet (320.7 ± 30.6 pg/mL) compared to a low-salt diet (172.9 ± 8.9 pg/mL, p<0.01) in 38 healthy, non-obese adults. This represents an approximate 85% increase in the hunger hormone. A positive correlation between 24-hour urinary sodium excretion and fasting ghrelin levels was also demonstrated, suggesting a dose-response relationship between salt intake and ghrelin production.
Why it matters
Epidemiological studies have linked high salt intake to obesity, but the biological mechanism was unclear. This study proposes that salt drives up ghrelin — the peptide hormone that stimulates hunger and fat storage — offering a concrete physiological pathway that could explain why salty diets contribute to weight gain beyond just calorie intake.
The numbers in context
n=38 · ghrelin on high salt: 320.7 pg/mL · ghrelin on low salt: 172.9 pg/mL · ~85% increase · p<0.01 · low salt: 3 g/day · high salt: 18 g/day · 7-day interventions
How the study worked
Crossover dietary intervention in 38 healthy, non-obese, normotensive adults aged 25–50 from rural Northern China. Participants were sequentially placed on a normal diet for 3 days, a low-salt diet (3 g/day NaCl) for 7 days, then a high-salt diet (18 g/day NaCl) for 7 days. Fasting plasma ghrelin was measured by ELISA and 24-hour urinary sodium excretion was monitored to verify dietary compliance.
Who was studied
Healthy, non-obese, normotensive adults aged 25–50 from a rural community in Northern China
What this study cannot tell us
Small sample size of 38 participants. The sequential (non-randomized) design means order effects cannot be ruled out. The study only measured ghrelin over short 7-day periods and did not track actual changes in appetite, food intake, or body weight. All participants were from a single rural Chinese community, limiting generalizability.
How to read the evidence
This is a small crossover intervention study without randomization of diet order. While the within-subject design strengthens comparisons, the small sample, short duration, and lack of blinding limit the strength of evidence.
When this study was published
Published in 2016, this study remains relevant as the relationship between dietary salt, appetite hormones, and obesity continues to be an active area of research.
The bigger picture
Public health guidelines have long focused on salt's role in blood pressure, but this study adds weight to the idea that salt also affects metabolic hormones involved in appetite and weight regulation. If confirmed in larger studies, ghrelin could be a key link in understanding why populations with high salt intake tend to have higher obesity rates.
Questions still open
- Does the ghrelin increase from high-salt diets actually translate into increased food intake and weight gain over longer periods?
- Would ghrelin receptor antagonists or other peptide-based therapies counteract salt-driven appetite increases?
- Is the salt-ghrelin relationship consistent across different ethnic populations and age groups?
Common questions
What is ghrelin and what does it do?
Does this mean eating less salt could help with weight loss?
Read the original research
Elevation of Fasting Ghrelin in Healthy Human Subjects Consuming a High-Salt Diet: A Novel Mechanism of Obesity?
Nutrients, 8(6)
Citation
Zhang, Yong; Li, Fenxia; Liu, Fu-Qiang; Chu, Chao; Wang, Yang; Wang, Dan; Guo, Tong-Shuai; Wang, Jun-Kui; Guan, Gong-Chang; Ren, Ke-Yu; Mu, Jian-Jun. (2016). Elevation of Fasting Ghrelin in Healthy Human Subjects Consuming a High-Salt Diet: A Novel Mechanism of Obesity?. Nutrients, 8(6). https://doi.org/10.3390/nu8060323