In 2024, researchers from Shanghai Jiao Tong University analyzed data from over 20,000 U.S. adults (average age 49) in the NHANES survey from 2003-2018, followed until 2019. They compared those eating in an 8-hour window (a common IF method) to those eating over 12-16 hours, adjusting for age, diet, and health factors.

In 2025, Matthew J. Breit and the University of Colorado Anschutz Medical Campus did a secondary look at a 12-month trial with 36 adults trying to lose weight. They compared two groups: one cut calories every day, the other did 4:3 intermittent fasting (normal eating 4 days, low calories 3 days). They tracked eating habits, hunger feelings, and hormones like ghrelin (hunger signal) and leptin (fullness signal) at start, 3 months, and 12 months using surveys and blood tests.

In 2025, Haohao Zhang and team at Zhengzhou University compared three diets for 52 obese people with type 2 diabetes: intermittent fasting (5:2 plan, eating normally five days and cutting calories two), time-restricted eating, and steady calorie reduction. They measured weight, blood sugar, and insulin response over months.

A 2025 meta-analysis by Kazeminasab et al. (Université Clermont Auvergne & CNRS) reviewed 35 randomized controlled trials with 1,266 adults. They found that combining intermittent fasting with exercise didn’t reduce VO₂max or leg/bench strength, but did slightly boost handgrip strength.

A 2025 feasibility trial by Meinlschmidt et al. studied 54 women with and without obesity after a 10-hour daytime fast. Both groups reported increased hunger and lower satiety, but mood effects differed: women with obesity experienced more depression and anger, while non-obese women mainly reported increased fatigue.