Research

Energy balance

In crossover diet studies without washout periods, the order of macronutrient manipulation (specifically Low Carbohydrate vs. Low Fat) significantly affects energy balance and body composition outcomes due to carryover effects from gut adaptations.

If you are designing or interpreting a nutrition study that switches between two diets without a break, the order matters. Starting with a high-volume, high-fiber diet (like a Low Carb diet in this study) before switching to a lower-volume diet can lead to significantly greater weight loss than the reverse order, likely because the gut adapts to the volume/fiber of the first diet, reducing intake in the second. For individuals, this suggests that the sequence of dietary changes might impact long-term adherence and results, though this specific mechanism (gut adaptation to mass) is most relevant in controlled settings.

GoodSupportsHIGH confidence
Subjects randomized to LCLF lost 2.9 ± 1.1 kg more body weight (p < 0.001) and 1.5 ± 0.6 kg more body fat (p = 0.03) than the LFLC group likely because the LCLF group consumed 922 ± 304 kcal/d less than the LFLC group (p = 0.0024). Reduced energy intake in LCLF vs LFLC was driven by the last two weeks (-1610 ± 306 kcal/d; p<0.00001) perhaps due to carryover effects of gut adaptations over the first two weeks arising from large differences in the mass of food (1295 ± 209 g/d; p<0.00001) and fiber intake (58 ± 5 g/d; p<0.00001).
Christina M. Sciarrillo et al. · medRxiv · 2023

Why this rating

Randomized crossover inpatient feeding study (gold standard for nutrition), but it is a secondary analysis of existing trials and the paper is a preprint.

Source

Diet order affects energy balance in randomized crossover feeding studies that vary in macronutrients but not ultra-processing

Christina M. Sciarrillo et al. · medRxiv · 2023

DOI 10.1101/2023.10.03.23296501

preprint · n=40Cited 6×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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