When people don't eat for 3 days, their noradrenaline levels go up, but not until after the second day of fasting.

Scientific Claim

During acute starvation in healthy young adults, plasma noradrenaline levels increase significantly only after 72 hours, with no change at 36 hours, indicating a delayed sympathetic nervous system response to prolonged fasting.

Evidence Quality Assessment

Claim Status

appropriately stated

Study Design Support

Design supports claim

Appropriate Language Strength

association

Can only show association/correlation

Assessment Explanation

The study design (cohort study) can describe associations between starvation and physiological changes. The claim uses 'increase' which appropriately reflects the observed association.

Source Excerpt

“Plasma noradrenaline levels changed with starvation (Fig. 4; time effect P < 0.001, ANOVA). There was no change in levels at 36 h compared with those at 12 h (P= 0.89), but the levels at 72 h were significantly greater than those at both 12 and 36 h (P= 0.002 and P < 0.001 respectively).”

Evidence from Studies

Supporting Evidence (1)

Why it supports

The study measured plasma noradrenaline levels at multiple time points during starvation and found a statistically significant increase only at 72 hours, with no significant change at 36 hours.

Score

The cardiovascular, metabolic and hormonal changes accompanying acute starvation in men and women

Cross-Sectional Study

Supported

Source Study

The cardiovascular, metabolic and hormonal changes accompanying acute starvation in men and women

Score: 50

DOI: 10.1079/bjn19940150

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