Research

Mixed

Very-low-calorie diets (VLCDs, <800 kcal/day) significantly increase the risk of symptomatic gallstones requiring hospitalization and cholecystectomy compared to low-calorie diets (LCDs, 1200-1500 kcal/day) during commercial weight loss programs.

If you choose a very-low-calorie diet (around 500 calories/day) for rapid weight loss, be aware that your risk of developing symptomatic gallstones requiring hospital care is about three times higher than if you ate a standard low-calorie diet (1200-1500 calories). Although the absolute risk is still low, discuss this with your doctor, especially if you have other risk factors. Some studies suggest supplements like ursodeoxycholic acid might help reduce this risk.

GoodSupportsHIGH confidence
The risk of symptomatic gallstones requiring hospitalization or cholecystectomy, albeit low, was 3-fold greater with VLCD than LCD during the 1-year commercial weight loss program.
Kari Johansson et al. · International Journal of Obesity · 2013

Why this rating

Large matched cohort study (n=3320 per group) with long-term follow-up and linkage to national health registers, though non-randomized.

Source

Risk of symptomatic gallstones and cholecystectomy after a very-low-calorie diet or low-calorie diet in a commercial weight loss program: 1-year matched cohort study

Kari Johansson et al. · International Journal of Obesity · 2013

DOI 10.1038/ijo.2013.83

cohort · n=6640Cited 84×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →