Lifestyle

48-hour fast

Lifestyle.

In practice

It depends on the case; there is no single guideline.

Effect by goal · level of evidence

Mood and brain function

harms Low study (A)

In 9 amateur weightlifters, fasting for 48 h increased parasympathetic activity but lowered resting frontal brain activity and worsened mood (more anger). A signal that long fasts may affect mood; very small sample.

View the study (study) →

In depth

Lifestyle · Highest evidence: Low · 1 finding

Findings

Mood and brain function — harms (Low, study). In 9 amateur weightlifters, fasting for 48 h increased parasympathetic activity but lowered resting frontal brain activity and worsened mood (more anger). A sign that long fasts can affect mood; very small sample. 28025637

Information, not medical advice. Prescription drugs require a doctor.

Information, not medical advice. Scientific evidence reflects the quality of the studies.