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The Study

Does regular walnut consumption lead to weight gain?

In simple terms

This study is like a fair test where people were randomly told to eat walnuts for 6 months or not, then switch. It shows that eating walnuts didn’t cause much weight gain — much less than we’d expect from the extra calories. But it doesn’t prove walnuts have magic weight-loss powers; it just shows they don’t make people gain as much weight as you’d think.

51%

Analysis score

51/ 90

Maximum 90 for a randomized controlled trial.

Where the score came from

Reporting0
Methodology65
Publication100
Statistical31
Study type (basis of the score)
Randomized Controlled Trial
Level 1b - Individual RCT
What’s the bottom line?

This study checked if eating walnuts every day makes people gain weight, even though walnuts have a lot of calories.

Where does this study sit?

Systematic Reviews & Meta-analyses

Max 100

Randomized Trials

Max 90

Cohort Studies

Max 72

Case-Control

Max 58

Cross-Sectional

Max 44

Case Reports & Series

Max 30

Expert Opinion

Max 5
StrongerWeaker
Randomized Trials
Level 1b
51

51 / 100

Quality score

Participants are randomly assigned to treatment or control groups, minimizing bias. Considered the gold standard for testing whether an intervention causes an effect.

Can establish causation

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Key takeaways

Summary

Based on the study abstract and findings.

  1. 1The weight gain is very small and may not matter much in real life.
  2. 2Your body might naturally eat less of other foods when you eat walnuts.
  3. 3People ate about 35g of walnuts daily for 6 months.
  4. 4They ate 133 extra calories per day.
  5. 5They gained only 0.4kg instead of the expected 3.1kg.
  6. 6BMI went up slightly by 0.1 units.

Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data

Publication

Journal

British Journal of Nutrition

Year

2005

Authors

J. Sabaté, Z. Cordero-MacIntyre, Gina Siapco, S. Torabian, E. Haddad

Open Access
124 citations
Analysis v3
Fit Body Science verdict — we translate health studies 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.