The Study
Postprandial Thermogenesis Is Increased 100% on a High-Protein, Low-Fat Diet versus a High-Carbohydrate, Low-Fat Diet in Healthy, Young Women
This study found that eating more protein made young women burn a little more energy after meals — but it didn’t test if they actually lost weight. So we know protein might make the body work harder after eating, but we don’t know if that helps people lose fat.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
When young women ate meals with lots of protein instead of carbs, their bodies used more energy to digest and process the food, and they kept more protein in their bodies.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 546 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — burning 100% more calories after meals could meaningfully affect daily energy balance and weight management.
- 2Body burned 100% more calories after meals on high-protein diet.
- 3Nitrogen balance: +7.6 gN/day vs.
- 4-0.4 gN/day.
- 5Urea nitrogen: 13.9 mg/dL vs.
- 611.2 mg/dL.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of the American College of Nutrition
Year
2002
Authors
C. Johnston, C. Day, P. Swan
Related Content
Claims (10)
The body uses more energy to process protein from food than it does to process carbohydrates or fats, resulting in greater heat production after eating protein.
Eating protein causes the body to burn more calories during digestion than eating the same amount of carbohydrates or fats, because breaking down and processing protein requires more energy.
Eating protein causes the body to burn more calories during digestion than eating the same amount of carbohydrates or fats.
In healthy women aged 19–22, eating a high-protein, low-fat meal results in a 100% higher increase in energy expenditure after eating compared to eating a high-carbohydrate, low-fat meal, when measured 2.5 hours later.
Healthy young women on a high-protein, low-fat diet retain more protein than those on a high-carbohydrate, low-fat diet, as measured by nitrogen balance.
In healthy women aged 19–22, eating a diet high in protein and low in fat causes a 100% higher increase in calorie burning after meals compared to a diet high in carbohydrates and low in fat, with the difference occurring after breakfast and dinner.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.