The Claim

Plasma norepinephrine levels do not increase following the consumption of protein or fat, indicating that sympathetic nervous system activation is not triggered by these macronutrients.

Source: Thermic effect of feeding in man: increased plasma norepinephrine levels following glucose but not protein or fat consumption.

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
20score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

How it works
1 study reviewed
In plain English

Eating protein or fat does not cause an increase in norepinephrine in the blood, which means the sympathetic nervous system does not become more active after consuming these nutrients.

See the scientific wording

Sympathetic nervous system activation, as indicated by plasma norepinephrine levels, does not increase following protein or fat consumption, challenging the hypothesis that SNS mediates the thermic effect of these macronutrients.

Why this might work

When a person eats protein or fat, the body does not release more norepinephrine into the blood, and the nervous system does not become more active. This means the extra energy burned after eating these foods does not come from the nervous system turning up calorie burning.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: Thermic effect of feeding in man: increased plasma norepinephrine levels following glucose but not protein or fat consumption.

    After eating protein or fat, the body doesn’t release more of the stress hormone norepinephrine, which means the nervous system isn’t responsible for burning extra calories from these foods. This matches what the claim says.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.