Australian nutritionist Hayley O’Neill notes that intermittent fasting, defined as short-term caloric restriction, can enhance cognitive performance, support vascular health, and align circadian rhythms.
Intermittent fasting encompasses several eating patterns that alternate between voluntary fasting or reduced calorie intake and periods of normal eating. The expert explains that daily fasting typically spans 12 to 16 hours, with the remaining hours devoted to meals.
During initial stages, individuals may feel fatigue, nausea, mood changes, irritability, headaches, and weakness. These symptoms occur as metabolism slows to conserve energy and blood sugar dips at the start of fasting phases. Over time, the body adapts by switching to ketones, produced when carbohydrate intake is limited, which helps fuel various bodily processes.
An increase in ketone levels may support cognitive function in adults, according to the nutritionist. Calorie restriction also reduces oxidative stress, a process where oxygen-related molecules can damage cells and tissues if not balanced by antioxidants.
Lower oxidative stress contributes to stronger blood vessels, including those supplying the brain. This improved vascular tone may help lower the risk factors associated with neurodegenerative conditions.
Adhering to a regular eating schedule may also help restore circadian rhythms, which are the natural daily fluctuations in bodily functions tied to the day–night cycle. Scheduling meals can provide a period of rest for the digestive system in the evening and during nighttime hours.
Myths about healthy eating have been addressed by nutrition experts, emphasizing that consistency, balanced nutrition, and evidence-based practices matter most for long-term health.