Research

Mixed

Short-term (2-week) crossover metabolic ward trials without washout periods are invalid for determining chronic macronutrient effects on energy intake and body fat due to massive, differential carry-over effects from physiologic adaptation.

Do not rely on short-term (under 4-6 weeks) diet studies to predict long-term weight loss outcomes. The body's metabolic adaptation to macronutrient changes (like ketosis or insulin shifts) takes weeks to months. Short trials often measure transient adaptation rather than chronic effects, leading to misleading conclusions about which diet is superior for fat loss.

GoodRefutesHIGH confidence
These findings, which tend to support rather than oppose the CIM, suggest that differential (unequal) carry-over effects and short duration, with no washout period, preclude causal inferences regarding chronic macronutrient effects from this trial.
Adrián Soto-Mota et al. · Journal of Nutrition · 2023

Why this rating

High-quality reanalysis of raw data from a controlled metabolic ward study, though limited by the specific context of the original trial.

Source

Physiologic Adaptation to Macronutrient Change Distorts Findings from Short Dietary Trials: Reanalysis of a Metabolic Ward Study

Adrián Soto-Mota et al. · Journal of Nutrition · 2023

DOI 10.1016/j.tjnut.2023.12.017

crossover · n=16Cited 10×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →