Two new studies suggest that the kinds of carbohydrates dominating modern diets may interfere with how full you feel in the moment and how your brain ages over time. A study from Virginia Tech found that participants consumed more snacks when exposed to an ultra-processed diet, even when not hungry. This tendency to snack when not hungry is a predictor of later weight gain in young people, especially adolescents, who are particularly susceptible to this effect.

Another long-term study analyzed dietary data from over 200,000 adults in the UK and found that diets high in refined carbs and sugars were associated with a higher risk of developing Alzheimer's disease. On the other hand, diets rich in low-glycemic-index foods, such as fruits, legumes, and whole grains, were linked to a decreased risk of cognitive decline and dementia. These findings highlight the importance of being mindful of the quality of carbohydrates consumed, as they can impact both immediate hunger cues and long-term brain health.