Each New Year, many resolve to prioritize health with new habits, including diets. But do these hold up scientifically? Johns Hopkins neuroscientist Mark Mattson, Ph.D., who has researched intermittent fasting's effects for 25 years and practiced it personally for 20, affirms in a review article that it can enhance a healthy lifestyle.
Intermittent fasting typically involves daily time-restricted eating (6-8 hour window) or the 5:2 approach, where you eat normally five days and limit to one moderate meal on two days a week.
Animal and human studies reveal that cycling fasting and eating bolsters cellular health via metabolic switching—an ancient adaptation to food scarcity. Cells deplete quick sugar fuels, then burn fat more slowly for energy.
This shift, per Mattson's findings, improves blood sugar control, stress resistance, and reduces inflammation. Constant three-meal-plus-snack routines prevent it, forgoing these gains.
Studies also show intermittent fasting lowers blood pressure, lipids, and resting heart rate in animals and humans.
Evidence mounts that it counters obesity and diabetes risks. At University Hospital of South Manchester NHS, 100 overweight women on 5:2 lost equal weight to calorie restrictors but excelled in insulin sensitivity and belly fat reduction.
Emerging research hints at brain benefits. A University of Toronto trial found 220 healthy adults on calorie restriction for two years improved memory on cognitive tests. More data could confirm fasting prevents neurodegeneration and dementia—or inspire mimicking drugs.
