In 2025, Jessica M. Preston and Romain Barrès from the University of Copenhagen studied 43 men aged 20-35 in a crossover trial. Participants spent three weeks on ultra-processed diets (like processed meats and snacks) and three on unprocessed diets (whole foods), with equal calories, followed by a washout period. They measured weight, hormones, and pollutants in blood.

In 2025, Lucas Santos and a team from Brazil studied Wistar rats fed a high-fat diet from weaning to mimic obesity. They split them into four groups: standard diet, standard diet with extra-virgin olive oil (EVOO), high-fat diet, and high-fat diet with EVOO. They checked body weight, blood sugar, satiety, and brain inflammation markers in the hypothalamic arcuate nucleus.

A 2025 study by Zheng et al. used data from over 16,000 Chinese adults between 1997–2011. They found that simply owning a refrigerator was linked to a 39% increase in daily calorie intake, a rise in fat and protein consumption, and more processed food in the diet—alongside higher obesity risk, especially among older adults and men.