Intermittent fasting trims weight and blood fats, but not blood pressure

Intermittent fasting has become one of the most popular weight-management strategies in the world, but most of the trial evidence comes from Western populations. Diet patterns, body composition and cardiometabolic risk profiles differ between populations, so it is fair to ask whether fasting regimens hold up in Chinese adults specifically. Weight, blood fats, insulin resistance and blood pressure all feed into long-term heart and metabolic health. This analysis set out to systematically pool the Chinese trial evidence for the first time.

The authors searched multiple databases for randomised controlled trials of intermittent fasting in Chinese participants, covering studies published up to October 2022. Nine trials with 899 participants qualified for inclusion. Time-restricted eating was the most common protocol, used in six of the nine trials, followed by alternate-day fasting. The primary outcome was weight loss after the intervention, with changes in cardiometabolic indicators such as blood fats, glucose measures and blood pressure as secondary outcomes. Results were pooled using a random-effects approach.

Intermittent fasting significantly reduced body weight, body mass index and body fat mass compared with control groups. It also improved insulin resistance and lowered LDL cholesterol and triglycerides. However, several markers did not shift to a statistically significant degree: waist circumference, total cholesterol, HDL cholesterol, fasting glucose, and both systolic and diastolic blood pressure. The wins were therefore concentrated in weight, body fat and a subset of blood markers rather than spread across the board.

The result broadly matches what fasting trials in other populations have tended to show: reliable short-term effects on weight and some metabolic markers, with less consistent movement elsewhere. It extends that picture to Chinese adults, a group that had not previously been studied systematically. The authors note that longer trials using different fasting strategies are still needed to generate robust evidence, so questions about durability, and about which regimen works best for whom, remain open.

This is a reason to view intermittent fasting as a credible weight-management option rather than a cure-all. In these trials it moved weight, body fat, insulin resistance and some blood fats, but left blood pressure, waist size and fasting glucose essentially unchanged. The evidence covers Chinese adults and mostly time-restricted eating, so it speaks most directly to that population and that pattern. Whether the benefits persist over the long run is not something these short trials can answer.